mdbx: release v0.11.2

Acknowledgements:
-----------------

 - [장세연 (Чан Се Ен)](https://github.com/sasgas) for contributing to C++ API.
 - [Alain Picard](https://github.com/castortech) for [Java bindings](https://github.com/castortech/mdbxjni).
 - [Alex Sharov](https://github.com/AskAlexSharov) for reporting and testing.
 - [Kris Zyp](https://github.com/kriszyp) for reporting and testing.
 - [Artem Vorotnikov](https://github.com/vorot93) for support [Rust wrapper](https://github.com/vorot93/libmdbx-rs).

Fixes:
------

 - [Fixed compilation](https://github.com/erthink/libmdbx/pull/239) with `devtoolset-9` on CentOS/RHEL 7.
 - [Fixed unexpected `MDBX_PROBLEM` error](https://github.com/erthink/libmdbx/issues/242) because of update an obsolete meta-page.
 - [Fixed returning `MDBX_NOTFOUND` error](https://github.com/erthink/libmdbx/issues/243) in case an inexact value found for `MDBX_GET_BOTH` operation.
 - [Fixed compilation](https://github.com/erthink/libmdbx/issues/245) without kernel/libc-devel headers.

Minors:
-------

 - Fixed `constexpr`-related macros for legacy compilers.
 - Allowed to define 'CMAKE_CXX_STANDARD` using an environment variable.
 - Simplified collection statistics of page operation .
 - Added `MDBX_FORCE_BUILD_AS_MAIN_PROJECT` cmake option.
 - Remove unneeded `#undef P_DIRTY`.

Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>

.circleci/config.yml

@@ -11,8 +11,7 @@ jobs:
       - TESTLOG: /tmp/test.log
     steps:
       - checkout
-      - run: make all
-      - run: ulimit -c unlimited && make check
+      - run: ulimit -c unlimited && MDBX_BUILD_OPTIONS="-DNDEBUG=1 -DMDBX_FORCE_ASSERTIONS=1" make test-ubsan
       - run:
           command: |
             mkdir -p /tmp/artifacts

.cirrus.yml

@@ -3,4 +3,4 @@ freebsd_instance:
 
 task:
   install_script: pkg install -y gmake bash git
-  script: git fetch --tags --force && gmake check
+  script: git fetch --tags --force && gmake MDBX_BUILD_OPTIONS="-DNDEBUG=1 -DMDBX_FORCE_ASSERTIONS=1" check

.github/FUNDING.yml

@@ -9,4 +9,4 @@ community_bridge: # Replace with a single Community Bridge project-name e.g., cl
 liberapay: # Replace with a single Liberapay username
 issuehunt: # Replace with a single IssueHunt username
 otechie: # Replace with a single Otechie username
-custom: ['https://sobe.ru/na/libmdbx', 'https://paypal.me/erthink', 'https://etherscan.io/address/0xe8a741a2a0a4850c5bdbb415aaaaf8fb46f06fb7']
+custom: ['https://sobe.ru/na/libmdbx', 'https://paypal.me/erthink', 'https://www.blockchain.com/en/eth/address/0x19291d8658f762f3baceae1700c0b9466572ceab', 'https://www.blockchain.com/en/btc/address/152u2KXNWWGHQS3qiBEoQaveWyPvaSWYGC']

.github/actions/spelling/excludes.txt

@@ -8,3 +8,4 @@
 ^\.gitignore$
 ^\.travis\.yml$
 ^packages/buildroot/
+^CMakeSettings\.json$

.github/actions/spelling/expect.txt

@@ -9,6 +9,7 @@ acision
 AClass
 adata
 addprefix
+addressof
 addsuffix
 addtogroup
 advapi
@@ -22,6 +23,7 @@ alevel
 alexey
 Alfke
 alignas
+alignof
 alldbs
 ALLDUPS
 ALLEXTERNALS
@@ -59,12 +61,14 @@ ARMEL
 ARMT
 Artem
 asan
+Ashikhmin
 asis
 asm
 asprintf
 aspx
 assection
 AstraLinux
+astralinux
 atal
 atexit
 atfork
@@ -96,6 +100,7 @@ bfin
 biarch
 bibtex
 BIGDATA
+bigdata
 bindir
 binfmt
 binutils
@@ -103,6 +108,7 @@ bitfield
 bitmaps
 bitmask
 bitness
+bitops
 blogger
 blogs
 blogspot
@@ -126,6 +132,7 @@ buflen
 bufsize
 BUGLIST
 bugzilla
+buildflags
 buildpack
 buildroot
 builtins
@@ -170,6 +177,7 @@ cifs
 cinttypes
 circleci
 claude
+climits
 clockid
 CLOEXEC
 closefile
@@ -283,6 +291,8 @@ ddl
 deadread
 deadwrite
 debian
+Debroux
+debrouxl
 debruijn
 DECC
 declspec
@@ -350,6 +360,8 @@ dprefix
 DPs
 dqiqg
 dreamsxin
+drv
+drvfs
 dsize
 dso
 dst
@@ -401,7 +413,6 @@ ELBRUSC
 ELBRUSCXX
 elif
 elseif
-elsif
 emoji
 emscripten
 EMULTIVAL
@@ -470,6 +481,7 @@ exactkey
 exactp
 excpt
 exe
+executables
 exename
 exherbo
 exitcode
@@ -488,6 +500,7 @@ FCXX
 fd
 fdatasync
 featuredarticles
+fedotov
 FEEDNAME
 feof
 ferror
@@ -510,6 +523,7 @@ Firefox
 firstvalue
 fixedpoint
 FIXME
+fjvallarino
 flagbit
 flg
 flipcoin
@@ -588,6 +602,7 @@ github
 githubusercontent
 gitignore
 glibc
+GLIBCXX
 globals
 gmail
 gmake
@@ -607,9 +622,11 @@ grep
 gtags
 gz
 gzip
+hackage
 HAGL
 hallvard
 hardcoded
+haskell
 HASSEMAPHORE
 hdiutil
 hdr
@@ -680,6 +697,7 @@ img
 impl
 IMPLIB
 inblock
+INCLUDEDIR
 indx
 INDXSIZE
 ini
@@ -694,6 +712,7 @@ inprocess
 INSTEADOF
 integerdup
 integerkey
+interoperability
 interprocedural
 intlimits
 intptr
@@ -774,6 +793,7 @@ klen
 KMGTPEZY
 knipp
 kp
+kriszyp
 ks
 ksize
 kstat
@@ -781,8 +801,10 @@ Kuntze
 kurt
 kuznik
 kval
+Lanfranchi
 largedata
 largepage
+lastbyte
 lastest
 lastvalue
 lastword
@@ -828,6 +850,7 @@ LLV
 llvm
 lmb
 lmdb
+lmdbx
 LMEM
 LNK
 lnps
@@ -873,6 +896,7 @@ MACROFILE
 MADV
 madvise
 mahlonsmith
+mailto
 maindb
 mainpage
 maj
@@ -958,6 +982,8 @@ microsoft
 Mikkelson
 minflt
 MINGW
+mingw
+minimalistic
 minkeys
 minlen
 MINSIZEREL
@@ -1095,6 +1121,7 @@ nordahead
 NOREPLACE
 NORESERVE
 noreturn
+NOSANITIZE
 nospill
 nosubdir
 nosync
@@ -1105,8 +1132,10 @@ notls
 notracking
 NOWAIT
 npages
+npmjs
 npos
 npr
+nproc
 nptl
 nreaders
 nrepeat
@@ -1252,6 +1281,7 @@ pmax
 pmccntr
 pmcntenset
 pmedvedev
+pmeta
 pmr
 pmuseren
 pmwkaa
@@ -1270,7 +1300,6 @@ ppc
 pragma
 pread
 prealloc
-prealloc'd
 PREDEF
 prefetch
 Prefetcher
@@ -1284,7 +1313,7 @@ PRIa
 PRId
 PRIi
 printf
-Prioritization
+prioritization
 PRIu
 prng
 prno
@@ -1292,6 +1321,7 @@ proba
 proces
 procfs
 progname
+programdata
 PROGRAMLISTING
 projectbrief
 projectlogo
@@ -1320,6 +1350,7 @@ putflags
 pv
 pvalue
 PVOID
+pwd
 PWIM
 PWIN
 PWOF
@@ -1379,11 +1410,13 @@ REALMEM
 REALPATH
 realtime
 Rebuffo
+rebuffo
 RECO
 redis
 reedom
 reefont
 refname
+refreshenv
 REGEX
 regexp
 reinited
@@ -1464,6 +1497,7 @@ semop
 sems
 sendfile
 sepkey
+sergey
 SETALL
 SETFD
 setlen
@@ -1646,6 +1680,7 @@ svg
 svnweb
 svr
 swait
+swappable
 symas
 SYMLINKS
 syncbytes
@@ -1714,6 +1749,7 @@ toolset
 tooltip
 torquem
 TOUPPER
+transcoder
 transcoding
 treeview
 tribudubois
@@ -1769,6 +1805,7 @@ underfilled
 UNDOC
 unicode
 UNIFORUM
+uninit
 uninstall
 UNINSTALLING
 uniq
@@ -1787,6 +1824,7 @@ updation
 upsert
 UPSERTING
 upsertion
+upto
 URG
 url
 usec
@@ -1812,6 +1850,7 @@ Vaefnrs
 valbool
 valgrind
 validator
+Vallarino
 valnum
 valsize
 valstr
@@ -1863,6 +1902,7 @@ webclient
 WERROR
 WEXITSTATUS
 WEXTRA
+whitelist
 wholetable
 WIFCONTINUED
 WIFEXITED
@@ -1932,6 +1972,7 @@ xsize
 yml
 Yota
 Yotta
+yperbasis
 Yq
 yuriev
 Zano
@@ -1945,3 +1986,4 @@ zi
 ZLIB
 zu
 zx
+Zyp

.github/workflows/MinGW.yml

@@ -3,8 +3,7 @@ name: MinGW
 on:
   pull_request:
   push:
-    branches-ignore:
-    - coverity_scan
+    branches: mingw
     paths-ignore:
     - '.circleci/**'
     - '.github/actions/spelling/**'
@@ -23,25 +22,44 @@ on:
 
 jobs:
   build:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [windows-latest]
+    runs-on: [windows-latest]
     steps:
     - uses: actions/checkout@v2
     - name: fetch tags
       run: git fetch --unshallow --tags --prune --force
-    - name: configure
-      run: cmake  -G "MinGW Makefiles" .
-    - name: build
-      run: cmake --build .
-#    - name: test
-#      shell: pwsh
-#      run: |
-#        & mdbx_test.exe --progress --console=no --pathname=test.db --dont-cleanup-after basic > test.log
-#        Get-Content test.log | Select-Object -last 42
-#        if ($LastExitCode -ne 0) {
-#            throw "Exec: $ErrorMessage"
-#        } else {
-#            & mdbx_chk.exe -nvv test.db | Tee-Object -file chk.log | Select-Object -last 42
-#        }
+    - name: append PATH
+      run: echo 'C:/ProgramData/chocolatey/lib/mingw/tools/install/mingw64/bin' >> $GITHUB_PATH
+    - name: update mingw64
+      # wanna version >= 10.2
+      run: choco upgrade mingw -y --no-progress && refreshenv
+    - name: configure-dll
+      shell: bash
+      run: |
+        mkdir build-dll && cd build-dll && \
+        cmake -G "MinGW Makefiles" -DMDBX_BUILD_SHARED_LIBRARY:BOOL=ON -DMDBX_INSTALL_STATIC:BOOL=OFF -DMDBX_ENABLE_TESTS:BOOL=ON ..
+    - name: build-dll
+      shell: bash
+      run: cd build-dll && cmake --build .
+    - name: test-dll
+      shell: bash
+      run: |
+        export "PATH=/c/programdata/chocolatey/lib/mingw/tools/install/mingw64/bin:$PATH" && \
+        cd build-dll && \
+        ./mdbx_test.exe --progress --console=no --pathname=test.db --dont-cleanup-after basic && \
+        ./mdbx_chk.exe -nvv test.db
+    - name: configure-static
+      shell: bash
+      run: |
+        mkdir build-static && cd build-static && \
+        cmake -G "MinGW Makefiles" -DMDBX_BUILD_SHARED_LIBRARY:BOOL=OFF -DMDBX_INSTALL_STATIC:BOOL=ON -DMDBX_ENABLE_TESTS:BOOL=ON ..
+    - name: build-static
+      shell: bash
+      run: |
+        cd build-static && cmake --build .
+    - name: test-static
+      shell: bash
+      run: |
+        export "PATH=/c/programdata/chocolatey/lib/mingw/tools/install/mingw64/bin:$PATH" && \
+        cd build-static && \
+        ./mdbx_test.exe --progress --console=no --pathname=test.db --dont-cleanup-after basic && \
+        ./mdbx_chk.exe -nvv test.db

.github/workflows/ci.yml

@@ -27,11 +27,11 @@ jobs:
     strategy:
       matrix:
 #, windows-latest
-        os: [ubuntu-latest, macos-latest, ubuntu-16.04]
+        os: [ubuntu-latest, macos-latest, ubuntu-18.04]
     steps:
     - uses: actions/checkout@v2
     - name: fetch tags
       run: git fetch --unshallow --tags --prune --force
     - name: make check
-      run: make --keep-going all && MALLOC_CHECK_=7 MALLOC_PERTURB_=42 make --keep-going check
+      run: make MDBX_BUILD_OPTIONS="-DNDEBUG=1 -DMDBX_FORCE_ASSERTIONS=1" --keep-going all && MALLOC_CHECK_=7 MALLOC_PERTURB_=42 make MDBX_BUILD_OPTIONS="-DNDEBUG=1 -DMDBX_FORCE_ASSERTIONS=1" --keep-going check
       shell: bash

.github/workflows/release-assets.yml

@@ -24,8 +24,8 @@ jobs:
         run: |
           echo "::set-output name=tarball::$(ls *.tar.gz)"
           echo "::set-output name=zip::$(ls *.zip)"
-          echo "::set-output name=suffix_unix::$(sed 's|^\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\)\.\(.*\)$|\1|' dist/VERSION)"
-          echo "::set-output name=suffix_dos::$(sed 's|^\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\)\.\(.*\)$|\1|' dist/VERSION | tr . _)"
+          echo "::set-output name=suffix_unix::$(sed 's|^\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\)\.\(.*\)$|\1|' dist/VERSION.txt)"
+          echo "::set-output name=suffix_dos::$(sed 's|^\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\)\.\(.*\)$|\1|' dist/VERSION.txt | tr . _)"
       - name: Create Release
         id: create_release
         uses: actions/create-release@v1

.gitignore

@@ -15,11 +15,13 @@
 .idea
 .le.ini
 .vs/
+.vscode/
 cmake-build-*
 @*
 core
 mdbx_example
 libmdbx.creator.user
+CMakeLists.txt.user
 mdbx_chk
 mdbx_copy
 mdbx_drop
@@ -36,6 +38,9 @@ valgrind.*
 src/version.c
 src/config.h
 dist/
+dist-check/
+dist-checked.tag
 *.tar*
 docs/Doxyfile
 docs/html/
+buildflags.tag

AUTHORS

@@ -2,6 +2,7 @@ Contributors
 ============
 
 - Alexey Naumov <alexey.naumov@gmail.com>
+- Andrew Ashikhmin <andrey.ashikhmin@gmail.com>
 - Chris Mikkelson <cmikk@qwest.net>
 - Claude Brisson <claude.brisson@gmail.com>
 - David Barbour <dmbarbour@gmail.com>
@@ -16,7 +17,7 @@ Contributors
 - John Hewson <john@jahewson.com>
 - Klaus Malorny <klaus.malorny@knipp.de>
 - Kurt Zeilenga <kurt.zeilenga@isode.com>
-- Leonid Yuriev <leo@yuriev.ru>, <lyuryev@ptsecurity.com>
+- Leonid Yuriev <leo@yuriev.ru>, <lyuryev@ptsecurity.ru>
 - Lorenz Bauer <lmb@cloudflare.com>
 - Luke Yeager <lyeager@nvidia.com>
 - Martin Hedenfalk <martin@bzero.se>

CMakeLists.txt

@@ -34,10 +34,14 @@
 ##  The Future will (be) Positive. Всё будет хорошо.
 ##
 
-cmake_minimum_required(VERSION 3.8.2)
+if(CMAKE_VERSION VERSION_LESS 3.12)
+  cmake_minimum_required(VERSION 3.8.2)
+else()
+  cmake_minimum_required(VERSION 3.12)
+endif()
 
 cmake_policy(PUSH)
-cmake_policy(VERSION 3.8.2)
+cmake_policy(VERSION ${CMAKE_MINIMUM_REQUIRED_VERSION})
 if(NOT CMAKE_VERSION VERSION_LESS 3.15)
   cmake_policy(SET CMP0091 NEW)
 endif()
@@ -70,7 +74,7 @@ if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.git" AND
     message(SEND_ERROR "Git command-line tool not found")
   endif()
   set(MDBX_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src")
-elseif(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/VERSION" AND
+elseif(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/VERSION.txt" AND
     EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/mdbx.c" AND
     EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/mdbx.c++" AND
     EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/config.h.in" AND
@@ -79,10 +83,20 @@ elseif(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/VERSION" AND
   set(MDBX_AMALGAMATED_SOURCE TRUE)
   set(MDBX_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 else()
-  message(FATAL_ERROR "Please use libmdbx as a git-submodule or the amalgamated source code")
+  message(FATAL_ERROR "\n"
+    "Please don't use tarballs nor zips which are automatically provided by Github!  "
+    "These archives do not contain version information and thus are unfit to build libmdbx.  "
+    "You can vote for ability of disabling auto-creation such unsuitable archives at https://github.community/t/disable-tarball\n"
+    "Instead of above, just clone the git repository, either download a tarball or zip with the properly amalgamated source core.  "
+    "For embedding libmdbx use a git-submodule or the amalgamated source code.\n"
+    "Please, avoid using any other techniques.")
 endif()
 
 if(DEFINED PROJECT_NAME)
+  option(MDBX_FORCE_BUILD_AS_MAIN_PROJECT "Force libmdbx to full control build options even it added as a subdirectory to your project." OFF)
+endif()
+
+if(DEFINED PROJECT_NAME AND NOT MDBX_FORCE_BUILD_AS_MAIN_PROJECT)
   set(SUBPROJECT ON)
   set(NOT_SUBPROJECT OFF)
   if(NOT MDBX_AMALGAMATED_SOURCE AND NOT DEFINED BUILD_TESTING)
@@ -222,8 +236,13 @@ else()
   endif()
 
   if(CMAKE_INTERPROCEDURAL_OPTIMIZATION_AVAILABLE
-      OR GCC_LTO_AVAILABLE OR MSVC_LTO_AVAILABLE OR CLANG_LTO_AVAILABLE)
+      OR GCC_LTO_AVAILABLE OR MSVC_LTO_AVAILABLE OR
+      (CLANG_LTO_AVAILABLE AND
+        ((DEFINED MDBX_ENABLE_TESTS AND NOT MDBX_ENABLE_TESTS)
+        OR NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.0)))
     option(INTERPROCEDURAL_OPTIMIZATION "Enable interprocedural/LTO optimization" ${INTERPROCEDURAL_OPTIMIZATION_DEFAULT})
+  else()
+    set(INTERPROCEDURAL_OPTIMIZATION OFF)
   endif()
 
   if(INTERPROCEDURAL_OPTIMIZATION)
@@ -279,11 +298,11 @@ else()
 
     if(UNIX)
       find_program(CLANG_FORMAT
-        NAMES clang-format-12 clang-format-11 clang-format-10 clang-format)
+        NAMES clang-format-13 clang-format)
       if(CLANG_FORMAT)
         execute_process(COMMAND ${CLANG_FORMAT} "--version" OUTPUT_VARIABLE clang_format_version_info)
         string(REGEX MATCH "version ([0-9]+)\\.([0-9]+)\\.([0-9]+)(.*)?" clang_format_version_info CLANG_FORMAT_VERSION)
-        if(clang_format_version_info AND NOT CLANG_FORMAT_VERSION VERSION_LESS 10.0)
+        if(clang_format_version_info AND NOT CLANG_FORMAT_VERSION VERSION_LESS 13.0)
           # Enable 'make reformat' target.
           add_custom_target(reformat
             VERBATIM
@@ -319,12 +338,21 @@ list(FIND CMAKE_CXX_COMPILE_FEATURES cxx_std_11 HAS_CXX11)
 list(FIND CMAKE_CXX_COMPILE_FEATURES cxx_std_14 HAS_CXX14)
 list(FIND CMAKE_CXX_COMPILE_FEATURES cxx_std_17 HAS_CXX17)
 list(FIND CMAKE_CXX_COMPILE_FEATURES cxx_std_20 HAS_CXX20)
+list(FIND CMAKE_CXX_COMPILE_FEATURES cxx_std_23 HAS_CXX23)
 if(NOT DEFINED MDBX_CXX_STANDARD)
+  if(DEFINED ENV{CMAKE_CXX_STANDARD})
+    set(CMAKE_CXX_STANDARD $ENV{CMAKE_CXX_STANDARD})
+  endif()
   if(DEFINED CMAKE_CXX_STANDARD)
     set(MDBX_CXX_STANDARD ${CMAKE_CXX_STANDARD})
-  elseif(NOT HAS_CXX20 LESS 0)
+  elseif(NOT HAS_CXX23 LESS 0
+      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12))
+    set(MDBX_CXX_STANDARD 23)
+  elseif(NOT HAS_CXX20 LESS 0
+      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9))
     set(MDBX_CXX_STANDARD 20)
-  elseif(NOT HAS_CXX17 LESS 0)
+  elseif(NOT HAS_CXX17 LESS 0
+      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5))
     set(MDBX_CXX_STANDARD 17)
   elseif(NOT HAS_CXX14 LESS 0)
     set(MDBX_CXX_STANDARD 14)
@@ -477,7 +505,7 @@ if(CMAKE_CXX_COMPILER_LOADED AND MDBX_CXX_STANDARD GREATER_EQUAL 11 AND MDBX_CXX
   endif()
   if(NOT MDBX_WITHOUT_MSVC_CRT
       AND NOT (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.8)
-      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4)
+      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.9)
       AND NOT (MSVC AND MSVC_VERSION LESS 1900))
     option(MDBX_BUILD_CXX "Build C++ portion" ON)
   else()
@@ -533,6 +561,13 @@ else()
   message(STATUS "Use C${MDBX_C_STANDARD} for libmdbx but C++ portion is disabled")
 endif()
 
+if(SUBPROJECT AND MSVC)
+  if(MSVC_VERSION LESS 1900)
+    message(FATAL_ERROR "At least \"Microsoft C/C++ Compiler\" version 19.0.24234.1 (Visual Studio 2015 Update 3) is required.")
+  endif()
+  add_compile_options("/utf-8")
+endif()
+
 macro(target_setup_options TARGET)
   if(DEFINED INTERPROCEDURAL_OPTIMIZATION)
     set_target_properties(${TARGET} PROPERTIES
@@ -543,22 +578,26 @@ macro(target_setup_options TARGET)
   if(MDBX_BUILD_CXX)
     set_target_properties(${TARGET} PROPERTIES
       CXX_STANDARD ${MDBX_CXX_STANDARD} CXX_STANDARD_REQUIRED ON)
+    if(MSVC AND NOT MSVC_VERSION LESS 1910)
+      target_compile_options(${TARGET} INTERFACE "/Zc:__cplusplus")
+    endif()
   endif()
-  if(CC_HAS_FASTMATH)
+  if(CC_HAS_FASTMATH
+      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10))
     target_compile_options(${TARGET} PRIVATE "-ffast-math")
   endif()
   if(CC_HAS_VISIBILITY)
     target_compile_options(${TARGET} PRIVATE "-fvisibility=hidden")
   endif()
   if(BUILD_FOR_NATIVE_CPU AND CC_HAS_ARCH_NATIVE)
-    target_compile_options(${TARGET} PUBLIC "-march=native")
+    target_compile_options(${TARGET} PRIVATE "-march=native")
   endif()
 endmacro()
 
 macro(libmdbx_setup_libs TARGET MODE)
   target_link_libraries(${TARGET} ${MODE} Threads::Threads)
   if(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
-    target_link_libraries(${TARGET} ${MODE} ntdll.lib)
+    target_link_libraries(${TARGET} ${MODE} ntdll)
     if(MDBX_NTDLL_EXTRA_IMPLIB AND MDBX_WITHOUT_MSVC_CRT)
       target_link_libraries(${TARGET} ${MODE} ntdll_extra)
     endif()
@@ -567,7 +606,7 @@ macro(libmdbx_setup_libs TARGET MODE)
   elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Android")
     target_link_libraries(${TARGET} ${MODE} log)
   endif()
-  if(LIBCXX_FILESYSTEM AND MDBX_BUILD_CXX)
+  if(MDBX_CXX_STANDARD GREATER_EQUAL 17 AND LIBCXX_FILESYSTEM AND MDBX_BUILD_CXX)
     target_link_libraries(${TARGET} ${MODE} ${LIBCXX_FILESYSTEM})
   endif()
 endmacro()
@@ -664,34 +703,34 @@ endif()
 # mdbx-shared-lib installation
 if(NOT DEFINED MDBX_DLL_INSTALL_DESTINATION)
   if(WIN32)
-    set(MDBX_DLL_INSTALL_DESTINATION bin)
+    set(MDBX_DLL_INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
   else()
-    set(MDBX_DLL_INSTALL_DESTINATION lib)
+    set(MDBX_DLL_INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR})
   endif()
 endif()
 if(MDBX_BUILD_SHARED_LIBRARY)
   if(CMAKE_VERSION VERSION_LESS 3.12)
     install(TARGETS mdbx EXPORT libmdbx
       LIBRARY DESTINATION ${MDBX_DLL_INSTALL_DESTINATION} COMPONENT runtime
-      OBJECTS DESTINATION lib COMPONENT devel
-      ARCHIVE DESTINATION lib COMPONENT devel
-      PUBLIC_HEADER DESTINATION include COMPONENT devel
-      INCLUDES DESTINATION include COMPONENT devel)
+      OBJECTS DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel
+      INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel)
   else()
     install(TARGETS mdbx EXPORT libmdbx
       LIBRARY DESTINATION ${MDBX_DLL_INSTALL_DESTINATION} COMPONENT runtime
       NAMELINK_COMPONENT devel
-      OBJECTS DESTINATION lib COMPONENT devel
-      ARCHIVE DESTINATION lib COMPONENT devel
-      PUBLIC_HEADER DESTINATION include COMPONENT devel
-      INCLUDES DESTINATION include COMPONENT devel)
+      OBJECTS DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel
+      INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel)
   endif()
 endif(MDBX_BUILD_SHARED_LIBRARY)
 
 # mdbx-tools installation
 if(MDBX_BUILD_TOOLS)
   if(NOT DEFINED MDBX_TOOLS_INSTALL_DESTINATION)
-    set(MDBX_TOOLS_INSTALL_DESTINATION bin)
+    set(MDBX_TOOLS_INSTALL_DESTINATION ${CMAKE_INSTALL_BINDIR})
   endif()
   install(
     TARGETS
@@ -706,7 +745,7 @@ if(MDBX_BUILD_TOOLS)
     COMPONENT runtime)
   if(MDBX_INSTALL_MANPAGES)
     if(NOT DEFINED MDBX_MAN_INSTALL_DESTINATION)
-      set(MDBX_MAN_INSTALL_DESTINATION man/man1)
+      set(MDBX_MAN_INSTALL_DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
     endif()
     install(
       FILES
@@ -725,26 +764,28 @@ endif(MDBX_BUILD_TOOLS)
 if(MDBX_INSTALL_STATIC)
   if(CMAKE_VERSION VERSION_LESS 3.12)
     install(TARGETS mdbx-static EXPORT libmdbx
-      LIBRARY DESTINATION lib COMPONENT devel
-      OBJECTS DESTINATION lib COMPONENT devel
-      ARCHIVE DESTINATION lib COMPONENT devel
-      PUBLIC_HEADER DESTINATION include COMPONENT devel
-      INCLUDES DESTINATION include COMPONENT devel)
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      OBJECTS DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel
+      INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel)
   else()
     install(TARGETS mdbx-static EXPORT libmdbx
-      LIBRARY DESTINATION lib COMPONENT devel
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
       NAMELINK_COMPONENT devel
-      OBJECTS DESTINATION lib COMPONENT devel
-      ARCHIVE DESTINATION lib COMPONENT devel
-      PUBLIC_HEADER DESTINATION include COMPONENT devel
-      INCLUDES DESTINATION include COMPONENT devel)
+      OBJECTS DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT devel
+      PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel
+      INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} COMPONENT devel)
   endif()
 endif(MDBX_INSTALL_STATIC)
 
 ################################################################################
 
 # collect options & build info
-string(TIMESTAMP MDBX_BUILD_TIMESTAMP UTC)
+if(NOT DEFINED MDBX_BUILD_TIMESTAMP)
+  string(TIMESTAMP MDBX_BUILD_TIMESTAMP UTC)
+endif()
 set(MDBX_BUILD_FLAGS ${CMAKE_C_FLAGS})
 if(MDBX_BUILD_CXX)
   set(MDBX_BUILD_FLAGS ${CMAKE_CXX_FLAGS})

CMakeSettings.json

@@ -0,0 +1,26 @@
+{
+  "configurations": [
+    {
+      "name": "x64-Debug",
+      "generator": "Ninja",
+      "configurationType": "Debug",
+      "inheritEnvironments": [ "msvc_x64_x64" ],
+      "buildRoot": "${env.USERPROFILE}\\CMakeBuilds\\libmdbx\\build\\${name}",
+      "installRoot": "${env.USERPROFILE}\\CMakeBuilds\\libmdbx\\install\\${name}",
+      "cmakeCommandArgs": "",
+      "buildCommandArgs": "",
+      "ctestCommandArgs": ""
+    },
+    {
+      "name": "x64-Release",
+      "generator": "Ninja",
+      "configurationType": "Release",
+      "inheritEnvironments": [ "msvc_x64_x64" ],
+      "buildRoot": "${env.USERPROFILE}\\CMakeBuilds\\libmdbx\\build\\${name}",
+      "installRoot": "${env.USERPROFILE}\\CMakeBuilds\\libmdbx\\install\\${name}",
+      "cmakeCommandArgs": "",
+      "buildCommandArgs": "",
+      "ctestCommandArgs": ""
+    }
+  ]
+}

ChangeLog.md

@@ -1,19 +1,211 @@
 ChangeLog
 ---------
 
-## v0.10.1 (in development)
-
-TODO:
+### TODO
 
+ - [Engage an "overlapped I/O" on Windows](https://github.com/erthink/libmdbx/issues/224).
+ - [Simple careful mode for working with corrupted DB](https://github.com/erthink/libmdbx/issues/223).
+ - [Move most of `mdbx_chk` functional to the library API](https://github.com/erthink/libmdbx/issues/204).
+ - [Replace SRW-lock on Windows to allow shrink DB with `MDBX_NOTLS` option](https://github.com/erthink/libmdbx/issues/210).
+ - [More flexible support of asynchronous runtime/framework(s)](https://github.com/erthink/libmdbx/issues/200).
+ - [Migration guide from LMDB to MDBX](https://github.com/erthink/libmdbx/issues/199).
  - [Get rid of dirty-pages list in MDBX_WRITEMAP mode](https://github.com/erthink/libmdbx/issues/193).
  - [Large/Overflow pages accounting for dirty-room](https://github.com/erthink/libmdbx/issues/192).
- - [C++ Buffer issue](https://github.com/erthink/libmdbx/issues/191).
- - Finalize C++ API (few typos and trivia bugs are still likely for now).
  - [Support for RAW devices](https://github.com/erthink/libmdbx/issues/124).
- - [Test framework issue](https://github.com/erthink/libmdbx/issues/127).
  - [Support MessagePack for Keys & Values](https://github.com/erthink/libmdbx/issues/115).
  - [Engage new terminology](https://github.com/erthink/libmdbx/issues/137).
- - Packages for [Astra Linux](https://astralinux.ru/), [ALT Linux](https://www.altlinux.org/), [ROSA Linux](https://www.rosalinux.ru/), Fedora/RHEL, Debian/Ubuntu.
+ - Finalize C++ API (there is still a small chance for a few typos and bugs).
+ - Packages for [Astra Linux](https://astralinux.ru/), [ALT Linux](https://www.altlinux.org/), [ROSA Linux](https://www.rosalinux.ru/), etc.
+
+
+## v0.11.2 at 2021-12-02
+
+Acknowledgements:
+
+ - [장세연 (Чан Се Ен)](https://github.com/sasgas) for contributing to C++ API.
+ - [Alain Picard](https://github.com/castortech) for [Java bindings](https://github.com/castortech/mdbxjni).
+ - [Alex Sharov](https://github.com/AskAlexSharov) for reporting and testing.
+ - [Kris Zyp](https://github.com/kriszyp) for reporting and testing.
+ - [Artem Vorotnikov](https://github.com/vorot93) for support [Rust wrapper](https://github.com/vorot93/libmdbx-rs).
+
+Fixes:
+
+ - [Fixed compilation](https://github.com/erthink/libmdbx/pull/239) with `devtoolset-9` on CentOS/RHEL 7.
+ - [Fixed unexpected `MDBX_PROBLEM` error](https://github.com/erthink/libmdbx/issues/242) because of update an obsolete meta-page.
+ - [Fixed returning `MDBX_NOTFOUND` error](https://github.com/erthink/libmdbx/issues/243) in case an inexact value found for `MDBX_GET_BOTH` operation.
+ - [Fixed compilation](https://github.com/erthink/libmdbx/issues/245) without kernel/libc-devel headers.
+
+Minors:
+
+ - Fixed `constexpr`-related macros for legacy compilers.
+ - Allowed to define 'CMAKE_CXX_STANDARD` using an environment variable.
+ - Simplified collection statistics of page operation .
+ - Added `MDBX_FORCE_BUILD_AS_MAIN_PROJECT` cmake option.
+ - Remove unneeded `#undef P_DIRTY`.
+
+
+## v0.11.1 at 2021-10-23
+
+### Backward compatibility break:
+
+The database format signature has been changed to prevent
+forward-interoperability with an previous releases, which may lead to a
+[false positive diagnosis of database corruption](https://github.com/erthink/libmdbx/issues/238)
+due to flaws of an old library versions.
+
+This change is mostly invisible:
+
+ - previously versions are unable to read/write a new DBs;
+ - but the new release is able to handle an old DBs and will silently upgrade ones.
+
+Acknowledgements:
+
+ - [Alex Sharov](https://github.com/AskAlexSharov) for reporting and testing.
+
+
+## v0.10.5 at 2021-10-13 (obsolete, please use v0.11.1)
+
+Unfortunately, the `v0.10.5` accidentally comes not full-compatible with previous releases:
+
+ - `v0.10.5` can read/processing DBs created by previous releases, i.e. the backward-compatibility is provided;
+ - however, previous releases may lead to false-corrupted state with DB that was touched by `v0.10.5`, i.e. the forward-compatibility is broken for `v0.10.4` and earlier.
+
+This cannot be fixed, as it requires fixing past versions, which as a result we will just get a current version.
+Therefore, it is recommended to use `v0.11.1` instead of `v0.10.5`.
+
+Acknowledgements:
+
+ - [Noel Kuntze](https://github.com/Thermi) for immediately bug reporting.
+
+Fixes:
+
+ - Fixed unaligned access regression after the `#pragma pack` fix for modern compilers.
+ - Added UBSAN-test to CI to avoid a regression(s) similar to lately fixed.
+ - Fixed possibility of meta-pages clashing after manually turn to a particular meta-page using `mdbx_chk` utility.
+
+Minors:
+
+ - Refined handling of weak or invalid meta-pages while a DB opening.
+ - Refined providing information for the @MAIN and @GC sub-databases of a last committed modification transaction's ID.
+
+
+## v0.10.4 at 2021-10-10
+
+Acknowledgements:
+
+ - [Artem Vorotnikov](https://github.com/vorot93) for support [Rust wrapper](https://github.com/vorot93/libmdbx-rs).
+ - [Andrew Ashikhmin](https://github.com/yperbasis) for contributing to C++ API.
+
+Fixes:
+
+ - Fixed possibility of looping update GC during transaction commit (no public issue since the problem was discovered inside [Positive Technologies](https://www.ptsecurity.ru)).
+ - Fixed `#pragma pack` to avoid provoking some compilers to generate code with [unaligned access](https://github.com/erthink/libmdbx/issues/235).
+ - Fixed `noexcept` for potentially throwing `txn::put()` of C++ API.
+
+Minors:
+
+ - Added stochastic test script for checking small transactions cases.
+ - Removed extra transaction commit/restart inside test framework.
+ - In debugging builds fixed a too small (single page) by default DB shrink threshold.
+
+
+## v0.10.3 at 2021-08-27
+
+Acknowledgements:
+
+ - [Francisco Vallarino](https://github.com/fjvallarino) for [Haskell bindings for libmdbx](https://hackage.haskell.org/package/libmdbx).
+ - [Alex Sharov](https://github.com/AskAlexSharov) for reporting and testing.
+ - [Andrea Lanfranchi](https://github.com/AndreaLanfranchi) for contributing.
+
+Extensions and improvements:
+
+ - Added `cursor::erase()` overloads for `key` and for `key-value`.
+ - Resolve minor Coverity Scan issues (no fixes but some hint/comment were added).
+ - Resolve minor UndefinedBehaviorSanitizer issues (no fixes but some workaround were added).
+
+Fixes:
+
+ - Always setup `madvise` while opening DB (fixes https://github.com/erthink/libmdbx/issues/231).
+ - Fixed checking legacy `P_DIRTY` flag (`0x10`) for nested/sub-pages.
+
+Minors:
+
+ - Fixed getting revision number from middle of history during amalgamation (GNU Makefile).
+ - Fixed search GCC tools for LTO (CMake scripts).
+ - Fixed/reorder dirs list for search CLANG tools for LTO (CMake scripts).
+ - Fixed/workarounds for CLANG < 9.x
+ - Fixed CMake warning about compatibility with 3.8.2
+
+
+## v0.10.2 at 2021-07-26
+
+Acknowledgements:
+
+ - [Alex Sharov](https://github.com/AskAlexSharov) for reporting and testing.
+ - [Andrea Lanfranchi](https://github.com/AndreaLanfranchi) for reporting bugs.
+ - [Lionel Debroux](https://github.com/debrouxl) for fuzzing tests and reporting bugs.
+ - [Sergey Fedotov](https://github.com/SergeyFromHell/) for [`node-mdbx` NodeJS bindings](https://www.npmjs.com/package/node-mdbx).
+ - [Kris Zyp](https://github.com/kriszyp) for [`lmdbx-store` NodeJS bindings](https://github.com/kriszyp/lmdbx-store).
+ - [Noel Kuntze](https://github.com/Thermi) for [draft Python bindings](https://github.com/erthink/libmdbx/commits/python-bindings).
+
+New features, extensions and improvements:
+
+ - [Allow to predefine/override `MDBX_BUILD_TIMESTAMP` for builds reproducibility](https://github.com/erthink/libmdbx/issues/201).
+ - Added options support for `long-stochastic` script.
+ - Avoided `MDBX_TXN_FULL` error for large transactions when possible.
+ - The `MDBX_READERS_LIMIT` increased to `32767`.
+ - Raise `MDBX_TOO_LARGE` under Valgrind/ASAN if being opened DB is 100 larger than RAM (to avoid hangs and OOM).
+ - Minimized the size of poisoned/unpoisoned regions to avoid Valgrind/ASAN stuck.
+ - Added more workarounds for QEMU for testing builds for 32-bit platforms, Alpha and Sparc architectures.
+ - `mdbx_chk` now skips iteration & checking of DB' records if corresponding page-tree is corrupted (to avoid `SIGSEGV`, ASAN failures, etc).
+ - Added more checks for [rare/fuzzing corruption cases](https://github.com/erthink/libmdbx/issues/217).
+
+Backward compatibility break:
+
+ - Use file `VERSION.txt` for version information instead of `VERSION` to avoid collision with `#include <version>`.
+ - Rename `slice::from/to_FOO_bytes()` to `slice::envisage_from/to_FOO_length()'.
+ - Rename `MDBX_TEST_EXTRA` make's variable to `MDBX_SMOKE_EXTRA`.
+ - Some details of the C++ API have been changed for subsequent freezing.
+
+Fixes:
+
+ - Fixed excess meta-pages checks in case `mdbx_chk` is called to check the DB for a specific meta page and thus could prevent switching to the selected meta page, even if the check passed without errors.
+ - Fixed [recursive use of SRW-lock on Windows cause by `MDBX_NOTLS` option](https://github.com/erthink/libmdbx/issues/203).
+ - Fixed [log a warning during a new DB creation](https://github.com/erthink/libmdbx/issues/205).
+ - Fixed [false-negative `mdbx_cursor_eof()` result](https://github.com/erthink/libmdbx/issues/207).
+ - Fixed [`make install` with non-GNU `install` utility (OSX, BSD)](https://github.com/erthink/libmdbx/issues/208).
+ - Fixed [installation by `CMake` in special cases by complete use `GNUInstallDirs`'s variables](https://github.com/erthink/libmdbx/issues/209).
+ - Fixed [C++ Buffer issue with `std::string` and alignment](https://github.com/erthink/libmdbx/issues/191).
+ - Fixed `safe64_reset()` for platforms without atomic 64-bit compare-and-swap.
+ - Fixed hang/shutdown on big-endian platforms without `__cxa_thread_atexit()`.
+ - Fixed [using bad meta-pages if DB was partially/recoverable corrupted](https://github.com/erthink/libmdbx/issues/217).
+ - Fixed extra `noexcept` for `buffer::&assign_reference()`.
+ - Fixed `bootid` generation on Windows for case of change system' time.
+ - Fixed [test framework keygen-related issue](https://github.com/erthink/libmdbx/issues/127).
+
+
+## v0.10.1 at 2021-06-01
+
+Acknowledgements:
+
+ - [Alexey Akhunov](https://github.com/AlexeyAkhunov) and [Alex Sharov](https://github.com/AskAlexSharov) for bug reporting and testing.
+ - [Andrea Lanfranchi](https://github.com/AndreaLanfranchi) for bug reporting and testing related to WSL2.
+
+New features:
+
+ - Added `-p` option to `mdbx_stat` utility for printing page operations statistic.
+ - Added explicit checking for and warning about using unfit github's archives.
+ - Added fallback from [OFD locking](https://bit.ly/3yFRtYC) to legacy non-OFD POSIX file locks on an `EINVAL` error.
+ - Added [Plan 9](https://en.wikipedia.org/wiki/9P_(protocol)) network file system to the whitelist for an ability to open a DB in exclusive mode.
+ - Support for opening from WSL2 environment a DB hosted on Windows drive and mounted via [DrvFs](https://docs.microsoft.com/it-it/archive/blogs/wsl/wsl-file-system-support#drvfs) (i.e by Plan 9 noted above).
+
+Fixes:
+
+ - Fixed minor "foo not used" warnings from modern C++ compilers when building the C++ part of the library.
+ - Fixed confusing/messy errors when build library from unfit github's archives (https://github.com/erthink/libmdbx/issues/197).
+ - Fixed `#​e​l​s​i​f` typo.
+ - Fixed rare unexpected `MDBX_PROBLEM` error during altering data in huge transactions due to wrong spilling/oust of dirty pages (https://github.com/erthink/libmdbx/issues/195).
+ - Re-Fixed WSL1/WSL2 detection with distinguishing (https://github.com/erthink/libmdbx/issues/97).
 
 
 ## v0.10.0 at 2021-05-09

GNUmakefile

@@ -29,18 +29,19 @@ INSTALL ?= install
 CC      ?= gcc
 CFLAGS_EXTRA ?=
 LD      ?= ld
-MDBX_BUILD_OPTIONS ?= -DNDEBUG=1
+MDBX_BUILD_OPTIONS ?=-DNDEBUG=1
+MDBX_BUILD_TIMESTAMP ?=$(shell date +%Y-%m-%dT%H:%M:%S%z)
 CFLAGS  ?= -std=gnu11 -O2 -g -Wall -Werror -Wextra -Wpedantic -ffunction-sections -fPIC -fvisibility=hidden -pthread -Wno-error=attributes $(CFLAGS_EXTRA)
 # -Wno-tautological-compare
 CXX     ?= g++
 # Choosing C++ standard with deferred simple variable expansion trick
-CXXSTD  ?= $(eval CXXSTD := $$(shell PROBE=$$$$([ -f mdbx.c++ ] && echo mdbx.c++ || echo src/mdbx.c++); for std in gnu++20 c++20 gnu++2a c++2a gnu++17 c++17 gnu++14 c++14 gnu+11 c++11; do $(CXX) -std=$$$${std} -c $$$${PROBE} -o /dev/null 2>/dev/null >/dev/null && echo "-std=$$$${std}" && exit; done))$(CXXSTD)
+CXXSTD  ?= $(eval CXXSTD := $$(shell PROBE=$$$$([ -f mdbx.c++ ] && echo mdbx.c++ || echo src/mdbx.c++); for std in gnu++23 c++23 gnu++2b c++2b gnu++20 c++20 gnu++2a c++2a gnu++17 c++17 gnu++1z c++1z gnu++14 c++14 gnu++1y c++1y gnu+11 c++11 gnu++0x c++0x; do $(CXX) -std=$$$${std} -c $$$${PROBE} -o /dev/null 2>std-$$$${std}.err >/dev/null && echo "-std=$$$${std}" && exit; done))$(CXXSTD)
 CXXFLAGS = $(CXXSTD) $(filter-out -std=gnu11,$(CFLAGS))
 
-# HINT: Try append '--no-as-needed,-lrt' for ability to built with modern glibc, but then run with the old.
-LIBS    ?= $(shell uname | grep -qi SunOS && echo "-lkstat") $(shell uname | grep -qi -e Darwin -e OpenBSD || echo "-lrt") $(shell uname | grep -qi Windows && echo "-lntdll")
+# TIP: Try append '--no-as-needed,-lrt' for ability to built with modern glibc, but then use with the old.
+LIBS    ?= $(strip -lm $(shell uname | grep -qi SunOS && echo "-lkstat") $(shell uname | grep -qi -e Darwin -e OpenBSD || echo "-lrt") $(shell uname | grep -qi Windows && echo "-lntdll"))
 
-LDFLAGS ?= $(shell $(LD) --help 2>/dev/null | grep -q -- --gc-sections && echo '-Wl,--gc-sections,-z,relro,-O1')$(shell $(LD) --help 2>/dev/null | grep -q -- -dead_strip && echo '-Wl,-dead_strip')
+LDFLAGS ?= $(strip $(shell $(LD) --help 2>/dev/null | grep -q -- --gc-sections && echo '-Wl,--gc-sections,-z,relro,-O1')$(shell $(LD) --help 2>/dev/null | grep -q -- -dead_strip && echo '-Wl,-dead_strip'))
 EXE_LDFLAGS ?= -pthread
 
 ################################################################################
@@ -58,8 +59,9 @@ HEADERS    := mdbx.h mdbx.h++
 LIBRARIES  := libmdbx.a libmdbx.$(SO_SUFFIX)
 TOOLS      := mdbx_stat mdbx_copy mdbx_dump mdbx_load mdbx_chk mdbx_drop
 MANPAGES   := mdbx_stat.1 mdbx_copy.1 mdbx_dump.1 mdbx_load.1 mdbx_chk.1 mdbx_drop.1
+TIP        := // TIP:
 
-.PHONY: all help options lib tools clean install uninstall
+.PHONY: all help options lib tools clean install uninstall check_buildflags_tag
 .PHONY: install-strip install-no-strip strip libmdbx mdbx show-options
 
 ifeq ("$(origin V)", "command line")
@@ -72,11 +74,11 @@ endif
 ifeq ($(MDBX_BUILD_VERBOSE),1)
   QUIET :=
   HUSH :=
-  $(info ## TIP: Use `make V=0` for quiet.)
+  $(info $(TIP) Use `make V=0` for quiet.)
 else
   QUIET := @
   HUSH := >/dev/null
-  $(info ## TIP: Use `make V=1` for verbose.)
+  $(info $(TIP) Use `make V=1` for verbose.)
 endif
 
 all: show-options $(LIBRARIES) $(TOOLS)
@@ -102,19 +104,22 @@ help:
 	@echo "  make bench-clean         - remove temp database(s) after benchmark"
 #> dist-cutoff-begin
 	@echo ""
+	@echo "  make smoke               - fast smoke test"
 	@echo "  make test                - basic test"
-	@echo "  make check               - basic test"
-	@echo "  make memcheck            - build with Valgrind's and test with memcheck tool"
-	@echo "  make test-valgrind       - build with Valgrind's and test with memcheck tool"
-	@echo "  make test-asan           - build with AddressSanitizer and test"
-	@echo "  make test-leak           - build with LeakSanitizer and test"
-	@echo "  make test-ubsan          - build with UndefinedBehaviourSanitizer and test"
-	@echo "  make cross-gcc           - run cross-compilation testset"
-	@echo "  make cross-qemu          - run cross-compilation and execution testset with QEMU"
+	@echo "  make check               - smoke test with amalgamation and installation checking"
+	@echo "  make long-test           - execute long test which runs for several weeks, or until you interrupt it"
+	@echo "  make memcheck            - build with Valgrind's and smoke test with memcheck tool"
+	@echo "  make test-valgrind       - build with Valgrind's and basic test with memcheck tool"
+	@echo "  make test-asan           - build with AddressSanitizer and basic test"
+	@echo "  make test-leak           - build with LeakSanitizer and basic test"
+	@echo "  make test-ubsan          - build with UndefinedBehaviourSanitizer and basic test"
+	@echo "  make cross-gcc           - check cross-compilation without test execution"
+	@echo "  make cross-qemu          - run cross-compilation and execution basic test with QEMU"
 	@echo "  make gcc-analyzer        - run gcc-analyzer (mostly useless for now)"
 	@echo "  make build-test          - build test executable(s)"
-	@echo "  make test-fault          - run transaction owner failure testcase"
-	@echo "  make test-singleprocess  - run single-process test (used by make cross-qemu)"
+	@echo "  make smoke-fault         - execute transaction owner failure smoke testcase"
+	@echo "  make smoke-singleprocess - execute single-process smoke test"
+	@echo "  make test-singleprocess  - execute single-process basic test (also used by make cross-qemu)"
 	@echo ""
 	@echo "  make dist                - build amalgamated source code"
 	@echo "  make doxygen             - build HTML documentation"
@@ -123,12 +128,14 @@ help:
 #< dist-cutoff-end
 
 show-options:
-	@echo "  MDBX_BUILD_OPTIONS =$(MDBX_BUILD_OPTIONS)"
-	@echo '## TIP: Use `make options` to listing available build options.'
+	@echo "  MDBX_BUILD_OPTIONS   = $(MDBX_BUILD_OPTIONS)"
+	@echo "  MDBX_BUILD_TIMESTAMP = $(MDBX_BUILD_TIMESTAMP)"
+	@echo '$(TIP) Use `make options` to listing available build options.'
+	@echo "  CC       =`which $(CC)` | `$(CC) --version | head -1`"
 	@echo "  CFLAGS   =$(CFLAGS)"
 	@echo "  CXXFLAGS =$(CXXFLAGS)"
 	@echo "  LDFLAGS  =$(LDFLAGS) $(LIBS) $(EXE_LDFLAGS)"
-	@echo '## TIP: Use `make help` to listing available targets.'
+	@echo '$(TIP) Use `make help` to listing available targets.'
 
 options:
 	@echo "  INSTALL      =$(INSTALL)"
@@ -149,7 +156,8 @@ options:
 	@echo "  EXE_LDFLAGS  =$(EXE_LDFLAGS)"
 	@echo "  LIBS         =$(LIBS)"
 	@echo ""
-	@echo "  MDBX_BUILD_OPTIONS =$(MDBX_BUILD_OPTIONS)"
+	@echo "  MDBX_BUILD_OPTIONS   = $(MDBX_BUILD_OPTIONS)"
+	@echo "  MDBX_BUILD_TIMESTAMP = $(MDBX_BUILD_TIMESTAMP)"
 	@echo ""
 	@echo "## Assortment items for MDBX_BUILD_OPTIONS:"
 	@echo "##   Note that the defaults should already be correct for most platforms;"
@@ -178,7 +186,17 @@ clean:
 	@echo '  REMOVE ...'
 	$(QUIET)rm -rf $(TOOLS) mdbx_test @* *.[ao] *.[ls]o *.$(SO_SUFFIX) *.dSYM *~ tmp.db/* \
 		*.gcov *.log *.err src/*.o test/*.o mdbx_example dist \
-		config.h src/config.h src/version.c *.tar*
+		config.h src/config.h src/version.c *.tar* buildflags.tag
+
+MDBX_BUILD_FLAGS =$(strip $(MDBX_BUILD_OPTIONS) $(CXXSTD) $(CFLAGS) $(LDFLAGS) $(LIBS))
+check_buildflags_tag:
+	$(QUIET)if [ "$(MDBX_BUILD_FLAGS)" != "$$(cat buildflags.tag 2>&1)" ]; then \
+		echo -n "  CLEAN for build with specified flags..." && \
+		$(MAKE) IOARENA=false CXXSTD= -s clean >/dev/null && echo " Ok" && \
+		echo '$(MDBX_BUILD_FLAGS)' > buildflags.tag; \
+	fi
+
+buildflags.tag: check_buildflags_tag
 
 libmdbx.a: mdbx-static.o mdbx++-static.o
 	@echo '  AR $@'
@@ -196,13 +214,13 @@ ifeq ($(wildcard mdbx.c),mdbx.c)
 # Amalgamated source code, i.e. distributed after `make dist`
 MAN_SRCDIR := man1/
 
-config.h: mdbx.c $(lastword $(MAKEFILE_LIST))
+config.h: buildflags.tag mdbx.c $(lastword $(MAKEFILE_LIST))
 	@echo '  MAKE $@'
-	$(QUIET)(echo '#define MDBX_BUILD_TIMESTAMP "$(shell date +%Y-%m-%dT%H:%M:%S%z)"' \
-	&& echo '#define MDBX_BUILD_FLAGS "$(CXXSTD) $(CFLAGS) $(LDFLAGS) $(LIBS)"' \
+	$(QUIET)(echo '#define MDBX_BUILD_TIMESTAMP "$(MDBX_BUILD_TIMESTAMP)"' \
+	&& echo "#define MDBX_BUILD_FLAGS \"$$(cat buildflags.tag)\"" \
 	&& echo '#define MDBX_BUILD_COMPILER "$(shell (LC_ALL=C $(CC) --version || echo 'Please use GCC or CLANG compatible compiler') | head -1)"' \
 	&& echo '#define MDBX_BUILD_TARGET "$(shell set -o pipefail; (LC_ALL=C $(CC) -v 2>&1 | grep -i '^Target:' | cut -d ' ' -f 2- || (LC_ALL=C $(CC) --version | grep -qi e2k && echo E2K) || echo 'Please use GCC or CLANG compatible compiler') | head -1)"' \
-	) > $@
+	) >$@
 
 mdbx-dylib.o: config.h mdbx.c mdbx.h $(lastword $(MAKEFILE_LIST))
 	@echo '  CC $@'
@@ -229,9 +247,9 @@ else
 ################################################################################
 # Plain (non-amalgamated) sources with test
 
-.PHONY: build-test check cross-gcc cross-qemu dist doxygen gcc-analyzer
-.PHONY: reformat release-assets tags test test-asan test-fault test-leak
-.PHONY: test-singleprocess test-ubsan test-valgrind memcheck
+.PHONY: build-test build-test-with-valgrind check cross-gcc cross-qemu dist doxygen gcc-analyzer long-test
+.PHONY: reformat release-assets tags smoke test test-asan smoke-fault test-leak
+.PHONY: smoke-singleprocess test-singleprocess test-ubsan test-valgrind memcheck
 
 define uname2osal
   case "$(UNAME)" in
@@ -247,7 +265,7 @@ define uname2titer
   esac
 endef
 
-DIST_EXTRA := LICENSE README.md CMakeLists.txt GNUmakefile Makefile ChangeLog.md VERSION config.h.in ntdll.def \
+DIST_EXTRA := LICENSE README.md CMakeLists.txt GNUmakefile Makefile ChangeLog.md VERSION.txt config.h.in ntdll.def \
 	$(addprefix man1/, $(MANPAGES)) cmake/compiler.cmake cmake/profile.cmake cmake/utils.cmake
 DIST_SRC   := mdbx.h mdbx.h++ mdbx.c mdbx.c++ $(addsuffix .c, $(TOOLS))
 
@@ -271,71 +289,90 @@ reformat:
 	fi
 
 MAN_SRCDIR := src/man1/
-ALLOY_DEPS := $(wildcard src/*)
-MDBX_GIT_VERSION = $(shell set -o pipefail; git describe --tags | sed -n 's|^v*\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\)\(.*\)|\1|p' || echo 'Please fetch tags and/or use non-obsolete git version')
-MDBX_GIT_REVISION = $(shell set -o pipefail; git rev-list --count HEAD ^`git tag --sort=-version:refname | sed -n '/^\(v[0-9]\+\.[0-9]\+\.[0-9]\+\)*/p;q' || echo 'failed_git_tag_with_sort'` || echo 'Please use non-obsolete git version')
-MDBX_GIT_TIMESTAMP = $(shell git show --no-patch --format=%cI HEAD || echo 'Please install latest get version')
-MDBX_GIT_DESCRIBE = $(shell git describe --tags --long --dirty=-dirty || echo 'Please fetch tags and/or install non-obsolete git version')
+ALLOY_DEPS := $(shell git ls-files src/)
+git_DIR := $(shell if [ -d .git ]; then echo .git; elif [ -s .git -a -f .git ]; then grep '^gitdir: ' .git | cut -d ':' -f 2; else echo git_directory_is_absent; fi)
+MDBX_GIT_VERSION = $(shell set -o pipefail; git describe --tags 2>&- | sed -n 's|^v*\([0-9]\{1,\}\.[0-9]\{1,\}\.[0-9]\{1,\}\)\(.*\)|\1|p' || echo 'Please fetch tags and/or use non-obsolete git version')
+MDBX_GIT_REVISION = $(shell set -o pipefail; git rev-list `git describe --tags --abbrev=0`..HEAD --count 2>&- || echo 'Please fetch tags and/or use non-obsolete git version')
+MDBX_GIT_TIMESTAMP = $(shell git show --no-patch --format=%cI HEAD 2>&- || echo 'Please install latest get version')
+MDBX_GIT_DESCRIBE = $(shell git describe --tags --long --dirty=-dirty 2>&- || echo 'Please fetch tags and/or install non-obsolete git version')
 MDBX_VERSION_SUFFIX = $(shell set -o pipefail; echo -n '$(MDBX_GIT_DESCRIBE)' | tr -c -s '[a-zA-Z0-9]' _)
-MDBX_BUILD_SOURCERY = $(shell set -o pipefail; $(MAKE) CXXSTD= -s src/version.c >/dev/null && (openssl dgst -r -sha256 src/version.c || sha256sum src/version.c || shasum -a 256 src/version.c) 2>/dev/null | cut -d ' ' -f 1 || echo 'Please install openssl or sha256sum or shasum')_$(MDBX_VERSION_SUFFIX)
+MDBX_BUILD_SOURCERY = $(shell set -o pipefail; $(MAKE) IOARENA=false CXXSTD= -s src/version.c >/dev/null && (openssl dgst -r -sha256 src/version.c || sha256sum src/version.c || shasum -a 256 src/version.c) 2>/dev/null | cut -d ' ' -f 1 || (echo 'Please install openssl or sha256sum or shasum' >&2 && echo sha256sum_is_no_available))_$(MDBX_VERSION_SUFFIX)
 MDBX_DIST_DIR = libmdbx-$(MDBX_VERSION_SUFFIX)
 
 # Extra options mdbx_test utility
-MDBX_TEST_EXTRA ?=
+MDBX_SMOKE_EXTRA ?=
 
-check: test dist
+check: DESTDIR = $(shell pwd)/@check-install
+check: test dist install
 
-test: build-test
-	@echo '  RUNNING `mdbx_test basic`...'
+smoke: build-test
+	@echo '  SMOKE `mdbx_test basic`...'
 	$(QUIET)rm -f $(TEST_DB) $(TEST_LOG).gz && (set -o pipefail; \
-		(./mdbx_test --table=+data.integer --keygen.split=29 --datalen.min=min --datalen.max=max --progress --console=no --repeat=$(TEST_ITER) --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_TEST_EXTRA) basic && \
-		./mdbx_test --mode=-writemap,-nosync-safe,-lifo --progress --console=no --repeat=12 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_TEST_EXTRA) basic) \
-		| tee >(gzip --stdout > $(TEST_LOG).gz) | tail -n 42) \
+		(./mdbx_test --table=+data.integer --keygen.split=29 --datalen.min=min --datalen.max=max --progress --console=no --repeat=$(TEST_ITER) --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_SMOKE_EXTRA) basic && \
+		./mdbx_test --mode=-writemap,-nosync-safe,-lifo --progress --console=no --repeat=12 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_SMOKE_EXTRA) basic) \
+		| tee >(gzip --stdout >$(TEST_LOG).gz) | tail -n 42) \
 	&& ./mdbx_chk -vvn $(TEST_DB) && ./mdbx_chk -vvn $(TEST_DB)-copy
 
-test-singleprocess: all mdbx_test
-	@echo '  RUNNING `mdbx_test --nested`...'
+smoke-singleprocess: build-test
+	@echo '  SMOKE `mdbx_test --nested`...'
 	$(QUIET)rm -f $(TEST_DB) $(TEST_LOG).gz && (set -o pipefail; \
-		(./mdbx_test --table=+data.integer --keygen.split=29 --datalen.min=min --datalen.max=max --progress --console=no --repeat=42 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_TEST_EXTRA) --hill && \
+		(./mdbx_test --table=+data.integer --keygen.split=29 --datalen.min=min --datalen.max=max --progress --console=no --repeat=42 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_SMOKE_EXTRA) --hill && \
 		./mdbx_test --progress --console=no --repeat=2 --pathname=$(TEST_DB) --dont-cleanup-before --dont-cleanup-after --copy && \
-		./mdbx_test --mode=-writemap,-nosync-safe,-lifo --progress --console=no --repeat=42 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_TEST_EXTRA) --nested) \
-		| tee >(gzip --stdout > $(TEST_LOG).gz) | tail -n 42) \
+		./mdbx_test --mode=-writemap,-nosync-safe,-lifo --progress --console=no --repeat=42 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_SMOKE_EXTRA) --nested) \
+		| tee >(gzip --stdout >$(TEST_LOG).gz) | tail -n 42) \
 	&& ./mdbx_chk -vvn $(TEST_DB) && ./mdbx_chk -vvn $(TEST_DB)-copy
 
-test-fault: all mdbx_test
-	@echo '  RUNNING `mdbx_test --inject-writefault=42 basic`...'
-	$(QUIET)rm -f $(TEST_DB) $(TEST_LOG).gz && (set -o pipefail; ./mdbx_test --progress --console=no --pathname=$(TEST_DB) --inject-writefault=42 --dump-config --dont-cleanup-after $(MDBX_TEST_EXTRA) basic \
-		| tee >(gzip --stdout > $(TEST_LOG).gz) | tail -n 42) \
+smoke-fault: build-test
+	@echo '  SMOKE `mdbx_test --inject-writefault=42 basic`...'
+	$(QUIET)rm -f $(TEST_DB) $(TEST_LOG).gz && (set -o pipefail; ./mdbx_test --progress --console=no --pathname=$(TEST_DB) --inject-writefault=42 --dump-config --dont-cleanup-after $(MDBX_SMOKE_EXTRA) basic \
+		| tee >(gzip --stdout >$(TEST_LOG).gz) | tail -n 42) \
 	; ./mdbx_chk -vvnw $(TEST_DB) && ([ ! -e $(TEST_DB)-copy ] || ./mdbx_chk -vvn $(TEST_DB)-copy)
 
-VALGRIND=valgrind --trace-children=yes --log-file=valgrind-%p.log --leak-check=full --track-origins=yes --error-exitcode=42 --suppressions=test/valgrind_suppress.txt
-memcheck test-valgrind:
-	@echo "  RUNNING \`mdbx_test basic\` under Valgrind's memcheck..."
-	$(QUIET)$(MAKE) CXXSTD= clean && $(MAKE) CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-Ofast -DMDBX_USE_VALGRIND" build-test && \
-	rm -f valgrind-*.log $(TEST_DB) $(TEST_LOG).gz && (set -o pipefail; ( \
-		$(VALGRIND) ./mdbx_test --table=+data.integer --keygen.split=29 --datalen.min=min --datalen.max=max --progress --console=no --repeat=2 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_TEST_EXTRA) basic && \
+test: build-test
+	@echo '  RUNNING `test/long_stochastic.sh --loops 2`...'
+	$(QUIET)test/long_stochastic.sh --loops 2 --db-upto-mb 256 --skip-make >$(TEST_LOG)
+
+long-test: build-test
+	@echo '  RUNNING `test/long_stochastic.sh --loops 42`...'
+	$(QUIET)test/long_stochastic.sh --loops 42 --db-upto-mb 1024 --skip-make
+
+test-singleprocess: build-test
+	@echo '  RUNNING `test/long_stochastic.sh --single --loops 2`...'
+	$(QUIET)test/long_stochastic.sh --single --loops 2 --db-upto-mb 256 --skip-make >$(TEST_LOG)
+
+test-valgrind: CFLAGS_EXTRA=-Ofast -DMDBX_USE_VALGRIND
+test-valgrind: build-test
+	@echo '  RUNNING `test/long_stochastic.sh --with-valgrind --loops 2`...'
+	$(QUIET)test/long_stochastic.sh --with-valgrind --loops 2 --db-upto-mb 256 --skip-make >$(TEST_LOG)
+
+memcheck: VALGRIND=valgrind --trace-children=yes --log-file=valgrind-%p.log --leak-check=full --track-origins=yes --error-exitcode=42 --suppressions=test/valgrind_suppress.txt
+memcheck: CFLAGS_EXTRA=-Ofast -DMDBX_USE_VALGRIND
+memcheck: build-test
+	@echo "  SMOKE \`mdbx_test basic\` under Valgrind's memcheck..."
+	$(QUIET)rm -f valgrind-*.log $(TEST_DB) $(TEST_LOG).gz && (set -o pipefail; ( \
+		$(VALGRIND) ./mdbx_test --table=+data.integer --keygen.split=29 --datalen.min=min --datalen.max=max --progress --console=no --repeat=2 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_SMOKE_EXTRA) basic && \
 		$(VALGRIND) ./mdbx_test --progress --console=no --pathname=$(TEST_DB) --dont-cleanup-before --dont-cleanup-after --copy && \
-		$(VALGRIND) ./mdbx_test --mode=-writemap,-nosync-safe,-lifo --progress --console=no --repeat=4 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_TEST_EXTRA) basic && \
+		$(VALGRIND) ./mdbx_test --mode=-writemap,-nosync-safe,-lifo --progress --console=no --repeat=4 --pathname=$(TEST_DB) --dont-cleanup-after $(MDBX_SMOKE_EXTRA) basic && \
 		$(VALGRIND) ./mdbx_chk -vvn $(TEST_DB) && \
 		$(VALGRIND) ./mdbx_chk -vvn $(TEST_DB)-copy \
-	) | tee >(gzip --stdout > $(TEST_LOG).gz) | tail -n 42)
+	) | tee >(gzip --stdout >$(TEST_LOG).gz) | tail -n 42)
 
 gcc-analyzer:
 	@echo '  RE-BUILD with `-fanalyzer` option...'
 	@echo "NOTE: There a lot of false-positive warnings at 2020-05-01 by pre-release GCC-10 (20200328, Red Hat 10.0.1-0.11)"
-	$(QUIET)$(MAKE) CXXSTD=$(CXXSTD) --always-make CFLAGS_EXTRA="-Og -fanalyzer -Wno-error" build-test
+	$(QUIET)$(MAKE) IOARENA=false CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-Og -fanalyzer -Wno-error" build-test
 
 test-ubsan:
-	@echo '  RE-CHECK with `-fsanitize=undefined` option...'
-	$(QUIET)$(MAKE) CXXSTD= clean && $(MAKE) CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-Ofast -fsanitize=undefined -fsanitize-undefined-trap-on-error" check
+	@echo '  RE-TEST with `-fsanitize=undefined` option...'
+	$(QUIET)$(MAKE) IOARENA=false CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-Ofast -fsanitize=undefined -fsanitize-undefined-trap-on-error" test
 
 test-asan:
-	@echo '  RE-CHECK with `-fsanitize=address` option...'
-	$(QUIET)$(MAKE) CXXSTD= clean && $(MAKE) CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-Os -fsanitize=address" check
+	@echo '  RE-TEST with `-fsanitize=address` option...'
+	$(QUIET)$(MAKE) IOARENA=false CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-Os -fsanitize=address" test
 
 test-leak:
-	@echo '  RE-CHECK with `-fsanitize=leak` option...'
-	$(QUIET)$(MAKE) CXXSTD= clean && $(MAKE) CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-fsanitize=leak" check
+	@echo '  RE-TEST with `-fsanitize=leak` option...'
+	$(QUIET)$(MAKE) IOARENA=false CXXSTD=$(CXXSTD) CFLAGS_EXTRA="-fsanitize=leak" test
 
 mdbx_example: mdbx.h example/example-mdbx.c libmdbx.$(SO_SUFFIX)
 	@echo '  CC+LD $@'
@@ -344,7 +381,7 @@ mdbx_example: mdbx.h example/example-mdbx.c libmdbx.$(SO_SUFFIX)
 build-test: all mdbx_example mdbx_test
 
 define test-rule
-$(patsubst %.cc,%.o,$(1)): $(1) $(TEST_INC) mdbx.h $(lastword $(MAKEFILE_LIST))
+$(patsubst %.cc,%.o,$(1)): $(1) $(TEST_INC) $(HEADERS) $(lastword $(MAKEFILE_LIST))
 	@echo '  CC $$@'
 	$(QUIET)$$(CXX) $$(CXXFLAGS) $$(MDBX_BUILD_OPTIONS) -c $(1) -o $$@
 
@@ -359,7 +396,18 @@ mdbx_test: $(TEST_OBJ) libmdbx.$(SO_SUFFIX)
 	@echo '  LD $@'
 	$(QUIET)$(CXX) $(CXXFLAGS) $(TEST_OBJ) -Wl,-rpath . -L . -l mdbx $(EXE_LDFLAGS) $(LIBS) -o $@
 
-git_DIR := $(shell if [ -d .git ]; then echo .git; elif [ -s .git -a -f .git ]; then grep '^gitdir: ' .git | cut -d ':' -f 2; else echo "Please use libmdbx as a git-submodule or the amalgamated source code" >&2 && echo git_directory; fi)
+$(git_DIR)/HEAD $(git_DIR)/index $(git_DIR)/refs/tags:
+	@echo '*** ' >&2
+	@echo '*** Please don''t use tarballs nor zips which are automatically provided by Github !' >&2
+	@echo '*** These archives do not contain version information and thus are unfit to build libmdbx.' >&2
+	@echo '*** You can vote for ability of disabling auto-creation such unsuitable archives at https://github.community/t/disable-tarball' >&2
+	@echo '*** ' >&2
+	@echo '*** Instead of above, just clone the git repository, either download a tarball or zip with the properly amalgamated source core.' >&2
+	@echo '*** For embedding libmdbx use a git-submodule or the amalgamated source code.' >&2
+	@echo '*** ' >&2
+	@echo '*** Please, avoid using any other techniques.' >&2
+	@echo '*** ' >&2
+	@false
 
 src/version.c: src/version.c.in $(lastword $(MAKEFILE_LIST)) $(git_DIR)/HEAD $(git_DIR)/index $(git_DIR)/refs/tags
 	@echo '  MAKE $@'
@@ -372,16 +420,16 @@ src/version.c: src/version.c.in $(lastword $(MAKEFILE_LIST)) $(git_DIR)/HEAD $(g
 		-e "s|\$${MDBX_VERSION_MINOR}|$(shell echo '$(MDBX_GIT_VERSION)' | cut -d . -f 2)|" \
 		-e "s|\$${MDBX_VERSION_RELEASE}|$(shell echo '$(MDBX_GIT_VERSION)' | cut -d . -f 3)|" \
 		-e "s|\$${MDBX_VERSION_REVISION}|$(MDBX_GIT_REVISION)|" \
-	src/version.c.in > $@
+	src/version.c.in >$@
 
-src/config.h: src/version.c $(lastword $(MAKEFILE_LIST))
+src/config.h: buildflags.tag src/version.c $(lastword $(MAKEFILE_LIST))
 	@echo '  MAKE $@'
-	$(QUIET)(echo '#define MDBX_BUILD_TIMESTAMP "$(shell date +%Y-%m-%dT%H:%M:%S%z)"' \
-	&& echo '#define MDBX_BUILD_FLAGS "$(CXXSTD) $(CFLAGS) $(LDFLAGS) $(LIBS)"' \
+	$(QUIET)(echo '#define MDBX_BUILD_TIMESTAMP "$(MDBX_BUILD_TIMESTAMP)"' \
+	&& echo "#define MDBX_BUILD_FLAGS \"$$(cat buildflags.tag)\"" \
 	&& echo '#define MDBX_BUILD_COMPILER "$(shell (LC_ALL=C $(CC) --version || echo 'Please use GCC or CLANG compatible compiler') | head -1)"' \
 	&& echo '#define MDBX_BUILD_TARGET "$(shell set -o pipefail; (LC_ALL=C $(CC) -v 2>&1 | grep -i '^Target:' | cut -d ' ' -f 2- || (LC_ALL=C $(CC) --version | grep -qi e2k && echo E2K) || echo 'Please use GCC or CLANG compatible compiler') | head -1)"' \
 	&& echo '#define MDBX_BUILD_SOURCERY $(MDBX_BUILD_SOURCERY)' \
-	) > $@
+	) >$@
 
 mdbx-dylib.o: src/config.h src/version.c src/alloy.c $(ALLOY_DEPS) $(lastword $(MAKEFILE_LIST))
 	@echo '  CC $@'
@@ -402,32 +450,32 @@ docs/Doxyfile: docs/Doxyfile.in src/version.c
 		-e "s|\$${MDBX_VERSION_MINOR}|$(shell echo '$(MDBX_GIT_VERSION)' | cut -d . -f 2)|" \
 		-e "s|\$${MDBX_VERSION_RELEASE}|$(shell echo '$(MDBX_GIT_VERSION)' | cut -d . -f 3)|" \
 		-e "s|\$${MDBX_VERSION_REVISION}|$(MDBX_GIT_REVISION)|" \
-	docs/Doxyfile.in > $@
+	docs/Doxyfile.in >$@
 
 define md-extract-section
 docs/__$(1).md: $(2)
 	@echo '  EXTRACT $1'
-	$(QUIET)sed -n '/<!-- section-begin $(1) -->/,/<!-- section-end -->/p' $$< > $$@ && test -s $$@
+	$(QUIET)sed -n '/<!-- section-begin $(1) -->/,/<!-- section-end -->/p' $$< >$$@ && test -s $$@
 
 endef
 $(foreach section,overview mithril characteristics improvements history usage performance bindings,$(eval $(call md-extract-section,$(section),README.md)))
 
 docs/overall.md: docs/__overview.md docs/_toc.md docs/__mithril.md docs/__history.md AUTHORS LICENSE
 	@echo '  MAKE $@'
-	$(QUIET)echo -e "\\mainpage Overall\n\\section brief Brief" | cat - $(filter %.md, $^) > $@ && echo -e "\n\n\nLicense\n=======\n" | cat AUTHORS - LICENSE >> $@
+	$(QUIET)echo -e "\\mainpage Overall\n\\section brief Brief" | cat - $(filter %.md, $^) >$@ && echo -e "\n\n\nLicense\n=======\n" | cat AUTHORS - LICENSE >>$@
 
 docs/intro.md: docs/_preface.md docs/__characteristics.md docs/__improvements.md docs/_restrictions.md docs/__performance.md
 	@echo '  MAKE $@'
-	$(QUIET)cat $^ | sed 's/^Performance comparison$$/Performance comparison {#performance}/' > $@
+	$(QUIET)cat $^ | sed 's/^Performance comparison$$/Performance comparison {#performance}/' >$@
 
 docs/usage.md: docs/__usage.md docs/_starting.md docs/__bindings.md
 	@echo '  MAKE $@'
-	$(QUIET)echo -e "\\page usage Usage\n\\section getting Building & Embedding" | cat - $^ | sed 's/^Bindings$$/Bindings {#bindings}/' > $@
+	$(QUIET)echo -e "\\page usage Usage\n\\section getting Building & Embedding" | cat - $^ | sed 's/^Bindings$$/Bindings {#bindings}/' >$@
 
 doxygen: docs/Doxyfile docs/overall.md docs/intro.md docs/usage.md mdbx.h mdbx.h++ src/options.h ChangeLog.md AUTHORS LICENSE
 	@echo '  RUNNING doxygen...'
 	$(QUIET)rm -rf docs/html && \
-	cat mdbx.h | tr '\n' '\r' | sed -e 's/LIBMDBX_INLINE_API\s*(\s*\([^,]\+\),\s*\([^,]\+\),\s*(\s*\([^)]\+\)\s*)\s*)\s*{/inline \1 \2(\3) {/g' | tr '\r' '\n' > docs/mdbx.h && \
+	cat mdbx.h | tr '\n' '\r' | sed -e 's/LIBMDBX_INLINE_API\s*(\s*\([^,]\+\),\s*\([^,]\+\),\s*(\s*\([^)]\+\)\s*)\s*)\s*{/inline \1 \2(\3) {/g' | tr '\r' '\n' >docs/mdbx.h && \
 	cp mdbx.h++ src/options.h ChangeLog.md docs/ && (cd docs && doxygen Doxyfile $(HUSH)) && cp AUTHORS LICENSE docs/html/
 
 mdbx++-dylib.o: src/config.h src/mdbx.c++ mdbx.h mdbx.h++ $(lastword $(MAKEFILE_LIST))
@@ -450,15 +498,14 @@ release-assets: libmdbx-sources-$(MDBX_VERSION_SUFFIX).tar.gz libmdbx-sources-$(
 
 dist-checked.tag: $(addprefix dist/, $(DIST_SRC) $(DIST_EXTRA))
 	@echo -n '  VERIFY amalgamated sources...'
-	$(QUIET)rm -rf $@ \
+	$(QUIET)rm -rf $@ dist/@tmp-shared_internals.inc \
 	&& if grep -R "define xMDBX_ALLOY" dist | grep -q MDBX_BUILD_SOURCERY; then echo "sed output is WRONG!" >&2; exit 2; fi \
-	&& rm -rf dist-check && cp -r -p dist dist-check && ($(MAKE) -C dist-check > dist-check/build.log 2> dist-check/build.err || (cat dist-check/build.err && exit 1)) \
-	&& touch $@ || (echo " FAILED! See dist-check/build.err" >&2; exit 2) && echo " Ok" \
-	&& rm dist/@tmp-shared_internals.inc
+	&& rm -rf dist-check && cp -r -p dist dist-check && ($(MAKE) IOARENA=false CXXSTD=$(CXXSTD) -C dist-check >dist-check.log 2>dist-check.err || (cat dist-check.err && exit 1)) \
+	&& touch $@ || (echo " FAILED! See dist-check.log and dist-check.err" >&2; exit 2) && echo " Ok"
 
 libmdbx-sources-$(MDBX_VERSION_SUFFIX).tar.gz: dist-checked.tag
 	@echo '  CREATE $@'
-	$(QUIET)$(TAR) -c $(shell LC_ALL=C $(TAR) --help | grep -q -- '--owner' && echo '--owner=0 --group=0') -f - -C dist $(DIST_SRC) $(DIST_EXTRA) | gzip -c -9 > $@
+	$(QUIET)$(TAR) -c $(shell LC_ALL=C $(TAR) --help | grep -q -- '--owner' && echo '--owner=0 --group=0') -f - -C dist $(DIST_SRC) $(DIST_EXTRA) | gzip -c -9 >$@
 
 libmdbx-sources-$(MDBX_VERSION_SUFFIX).zip: dist-checked.tag
 	@echo '  CREATE $@'
@@ -475,26 +522,26 @@ dist/mdbx.h++: mdbx.h++ src/version.c $(lastword $(MAKEFILE_LIST))
 dist/@tmp-shared_internals.inc: src/version.c $(ALLOY_DEPS) $(lastword $(MAKEFILE_LIST))
 	@echo '  ALLOYING...'
 	$(QUIET)mkdir -p dist \
-	&& echo '#define xMDBX_ALLOY 1' > dist/@tmp-sed.inc && echo '#define MDBX_BUILD_SOURCERY $(MDBX_BUILD_SOURCERY)' >> dist/@tmp-sed.inc \
+	&& echo '#define xMDBX_ALLOY 1' >dist/@tmp-sed.inc && echo '#define MDBX_BUILD_SOURCERY $(MDBX_BUILD_SOURCERY)' >>dist/@tmp-sed.inc \
 	&& sed \
 		-e '/#pragma once/r dist/@tmp-sed.inc' \
 		-e 's|#include "../mdbx.h"|@INCLUDE "mdbx.h"|' \
 		-e '/#include "defs.h"/r src/defs.h' \
 		-e '/#include "osal.h"/r src/osal.h' \
 		-e '/#include "options.h"/r src/options.h' \
-		src/internals.h > $@ \
+		src/internals.h >$@ \
 	&& rm -rf dist/@tmp-sed.inc
 
 dist/mdbx.c: dist/@tmp-shared_internals.inc $(lastword $(MAKEFILE_LIST))
 	@echo '  MAKE $@'
 	$(QUIET)mkdir -p dist && (cat dist/@tmp-shared_internals.inc \
 	&& cat src/core.c src/osal.c src/version.c src/lck-windows.c src/lck-posix.c \
-	) | grep -v -e '#include "' -e '#pragma once' | sed 's|@INCLUDE|#include|' > $@
+	) | grep -v -e '#include "' -e '#pragma once' | sed 's|@INCLUDE|#include|' >$@
 
 dist/mdbx.c++: dist/@tmp-shared_internals.inc src/mdbx.c++ $(lastword $(MAKEFILE_LIST))
 	@echo '  MAKE $@'
 	$(QUIET)mkdir -p dist && (cat dist/@tmp-shared_internals.inc && cat src/mdbx.c++) \
-	| grep -v -e '#include "' -e '#pragma once' | sed 's|@INCLUDE|#include|;s|"mdbx.h"|"mdbx.h++"|' > $@
+	| grep -v -e '#include "' -e '#pragma once' | sed 's|@INCLUDE|#include|;s|"mdbx.h"|"mdbx.h++"|' >$@
 
 define dist-tool-rule
 dist/$(1).c: src/$(1).c src/wingetopt.h src/wingetopt.c \
@@ -505,7 +552,7 @@ dist/$(1).c: src/$(1).c src/wingetopt.h src/wingetopt.c \
 		-e '/#include "wingetopt.h"/r src/wingetopt.c' \
 		src/$(1).c \
 	| grep -v -e '#include "' -e '#pragma once' -e '#define xMDBX_ALLOY' \
-	| sed 's|@INCLUDE|#include|' > $$@
+	| sed 's|@INCLUDE|#include|' >$$@
 
 endef
 $(foreach file,$(TOOLS),$(eval $(call dist-tool-rule,$(file))))
@@ -513,14 +560,14 @@ $(foreach file,$(TOOLS),$(eval $(call dist-tool-rule,$(file))))
 define dist-extra-rule
 dist/$(1): $(1)
 	@echo '  REFINE $$@'
-	$(QUIET)mkdir -p $$(dir $$@) && sed -e '/^#> dist-cutoff-begin/,/^#< dist-cutoff-end/d' $$< > $$@
+	$(QUIET)mkdir -p $$(dir $$@) && sed -e '/^#> dist-cutoff-begin/,/^#< dist-cutoff-end/d' $$< >$$@
 
 endef
-$(foreach file,$(filter-out man1/% VERSION %.in ntdll.def,$(DIST_EXTRA)),$(eval $(call dist-extra-rule,$(file))))
+$(foreach file,$(filter-out man1/% VERSION.txt %.in ntdll.def,$(DIST_EXTRA)),$(eval $(call dist-extra-rule,$(file))))
 
-dist/VERSION: src/version.c
+dist/VERSION.txt: src/version.c
 	@echo '  MAKE $@'
-	$(QUIET)mkdir -p dist/ && echo "$(MDBX_GIT_VERSION).$(MDBX_GIT_REVISION)" > $@
+	$(QUIET)mkdir -p dist/ && echo "$(MDBX_GIT_VERSION).$(MDBX_GIT_REVISION)" >$@
 
 dist/ntdll.def: src/ntdll.def
 	@echo '  COPY $@'
@@ -539,7 +586,7 @@ endif
 ################################################################################
 # Cross-compilation simple test
 
-CROSS_LIST = sparc64-linux-gnu-gcc alpha-linux-gnu-gcc mips-linux-gnu-gcc \
+CROSS_LIST = mips-linux-gnu-gcc \
 	powerpc64-linux-gnu-gcc powerpc-linux-gnu-gcc \
 	arm-linux-gnueabihf-gcc aarch64-linux-gnu-gcc \
 	sh4-linux-gnu-gcc mips64-linux-gnuabi64-gcc \
@@ -550,7 +597,7 @@ CROSS_LIST = sparc64-linux-gnu-gcc alpha-linux-gnu-gcc mips-linux-gnu-gcc \
 # s390x-linux-gnu-gcc         - works (previously: qemu hang/abort)
 # sparc64-linux-gnu-gcc       - coredump (qemu mmap-troubles, previously: qemu fails fcntl for F_SETLK/F_GETLK)
 # alpha-linux-gnu-gcc         - coredump (qemu mmap-troubles)
-CROSS_LIST_NOQEMU =
+CROSS_LIST_NOQEMU = sparc64-linux-gnu-gcc alpha-linux-gnu-gcc
 
 cross-gcc:
 	@echo '  Re-building by cross-compiler for: $(CROSS_LIST_NOQEMU) $(CROSS_LIST)'
@@ -558,7 +605,7 @@ cross-gcc:
 	@echo "FOR INSTANCE: apt install g++-aarch64-linux-gnu g++-alpha-linux-gnu g++-arm-linux-gnueabihf g++-hppa-linux-gnu g++-mips-linux-gnu g++-mips64-linux-gnuabi64 g++-powerpc-linux-gnu g++-powerpc64-linux-gnu g++-s390x-linux-gnu g++-sh4-linux-gnu g++-sparc64-linux-gnu"
 	$(QUIET)for CC in $(CROSS_LIST_NOQEMU) $(CROSS_LIST); do \
 		echo "===================== $$CC"; \
-		$(MAKE) CXXSTD= clean && CC=$$CC CXX=$$(echo $$CC | sed 's/-gcc/-g++/') EXE_LDFLAGS=-static $(MAKE) all || exit $$?; \
+		$(MAKE) IOARENA=false CXXSTD= clean && CC=$$CC CXX=$$(echo $$CC | sed 's/-gcc/-g++/') EXE_LDFLAGS=-static $(MAKE) IOARENA=false all || exit $$?; \
 	done
 
 # Unfortunately qemu don't provide robust support for futexes.
@@ -571,21 +618,25 @@ cross-qemu:
 	@echo "	2) apt install binfmt-support qemu-user-static qemu-user qemu-system-arm qemu-system-mips qemu-system-misc qemu-system-ppc qemu-system-sparc"
 	$(QUIET)for CC in $(CROSS_LIST); do \
 		echo "===================== $$CC + qemu"; \
-		$(MAKE) CXXSTD= clean && \
-			MDBX_TEST_EXTRA="$(MDBX_TEST_EXTRA)$$(echo $$CC | grep -q -e alpha -e sparc && echo ' --size-upper=64M --size-lower=64M')" \
+		$(MAKE) IOARENA=false CXXSTD= clean && \
 			CC=$$CC CXX=$$(echo $$CC | sed 's/-gcc/-g++/') EXE_LDFLAGS=-static MDBX_BUILD_OPTIONS="-DMDBX_SAFE4QEMU $(MDBX_BUILD_OPTIONS)" \
-			$(MAKE) test-singleprocess || exit $$?; \
+			$(MAKE) IOARENA=false smoke-singleprocess test-singleprocess || exit $$?; \
 	done
 
 #< dist-cutoff-end
 
 install: $(LIBRARIES) $(TOOLS) $(HEADERS)
 	@echo '  INSTALLING...'
-	$(INSTALL) -D -p $(EXE_INSTALL_FLAGS) -t $(DESTDIR)$(prefix)/bin$(suffix) $(TOOLS) && \
-	$(INSTALL) -D -p $(EXE_INSTALL_FLAGS) -t $(DESTDIR)$(prefix)/lib$(suffix) $(filter-out libmdbx.a,$(LIBRARIES)) && \
-	$(INSTALL) -D -p -t $(DESTDIR)$(prefix)/lib$(suffix) libmdbx.a && \
-	$(INSTALL) -D -p -m 444 -t $(DESTDIR)$(prefix)/include $(HEADERS) && \
-	$(INSTALL) -D -p -m 444 -t $(DESTDIR)$(mandir)/man1 $(addprefix $(MAN_SRCDIR), $(MANPAGES))
+	$(QUIET)mkdir -p $(DESTDIR)$(prefix)/bin$(suffix) && \
+		$(INSTALL) -p $(EXE_INSTALL_FLAGS) $(TOOLS) $(DESTDIR)$(prefix)/bin$(suffix)/ && \
+	mkdir -p $(DESTDIR)$(prefix)/lib$(suffix)/ && \
+		$(INSTALL) -p $(EXE_INSTALL_FLAGS) $(filter-out libmdbx.a,$(LIBRARIES)) $(DESTDIR)$(prefix)/lib$(suffix)/ && \
+	mkdir -p $(DESTDIR)$(prefix)/lib$(suffix)/ && \
+		$(INSTALL) -p libmdbx.a $(DESTDIR)$(prefix)/lib$(suffix)/ && \
+	mkdir -p $(DESTDIR)$(prefix)/include/ && \
+		$(INSTALL) -p -m 444 $(HEADERS) $(DESTDIR)$(prefix)/include/ && \
+	mkdir -p $(DESTDIR)$(mandir)/man1/ && \
+		$(INSTALL) -p -m 444 $(addprefix $(MAN_SRCDIR), $(MANPAGES)) $(DESTDIR)$(mandir)/man1/
 
 install-strip: EXE_INSTALL_FLAGS = -s
 install-strip: install
@@ -603,23 +654,32 @@ uninstall:
 ################################################################################
 # Benchmarking by ioarena
 
-IOARENA ?= $(shell \
+ifeq ($(origin IOARENA),undefined)
+IOARENA := $(shell \
   (test -x ../ioarena/@BUILD/src/ioarena && echo ../ioarena/@BUILD/src/ioarena) || \
   (test -x ../../@BUILD/src/ioarena && echo ../../@BUILD/src/ioarena) || \
-  (test -x ../../src/ioarena && echo ../../src/ioarena) || which ioarena)
+  (test -x ../../src/ioarena && echo ../../src/ioarena) || which ioarena 2>&- || \
+  (echo false && echo '$(TIP) Clone and build the https://github.com/pmwkaa/ioarena.git within a neighbouring directory for availability of benchmarking.' >&2))
+endif
 NN	?= 25000000
 BENCH_CRUD_MODE ?= nosync
 
-ifneq ($(wildcard $(IOARENA)),)
-
-.PHONY: bench bench-clean bench-couple re-bench bench-quartet bench-triplet
-
 bench-clean:
 	@echo '  REMOVE bench-*.txt _ioarena/*'
 	$(QUIET)rm -rf bench-*.txt _ioarena/*
 
 re-bench: bench-clean bench
 
+ifeq ($(or $(IOARENA),false),false)
+bench bench-quartet bench-triplet bench-couple:
+	$(QUIET)echo 'The `ioarena` benchmark is required.' >&2 && \
+	echo 'Please clone and build the https://github.com/pmwkaa/ioarena.git within a neighbouring `ioarena` directory.' >&2 && \
+	false
+
+else
+
+.PHONY: bench bench-clean bench-couple re-bench bench-quartet bench-triplet
+
 define bench-rule
 bench-$(1)_$(2).txt: $(3) $(IOARENA) $(lastword $(MAKEFILE_LIST))
 	@echo '  RUNNING ioarena for $1/$2...'

Makefile

@@ -5,8 +5,8 @@ clean install install-no-strip install-strip strip tools uninstall \
 bench bench-clean bench-couple bench-quartet bench-triplet re-bench \
 lib libmdbx mdbx mdbx_chk mdbx_copy mdbx_drop mdbx_dump mdbx_load mdbx_stat \
 check dist memcheck cross-gcc cross-qemu doxygen gcc-analyzer reformat \
-release-assets tags test build-test mdbx_test \
-test-asan test-fault test-leak test-singleprocess test-ubsan test-valgrind:
+release-assets tags test build-test mdbx_test smoke smoke-fault smoke-singleprocess \
+test-asan test-leak test-singleprocess test-ubsan test-valgrind:
 	@CC=$(CC) \
 	CXX=`if test -n "$(CXX)" && which "$(CXX)" > /dev/null; then echo "$(CXX)"; elif test -n "$(CCC)" && which "$(CCC)" > /dev/null; then echo "$(CCC)"; else echo "c++"; fi` \
 	`which gmake || which gnumake || echo 'echo "GNU Make 3.80 or above is required"; exit 2;'` \

README.md

@@ -91,7 +91,7 @@ _MithrilDB_ is a rightly relevant name.
     - [Improvements beyond LMDB](#improvements-beyond-lmdb)
     - [History & Acknowledgments](#history)
 - [Usage](#usage)
-    - [Building](#building)
+    - [Building and Testing](#building-and-testing)
     - [API description](#api-description)
     - [Bindings](#bindings)
 - [Performance comparison](#performance-comparison)
@@ -154,8 +154,8 @@ transaction journal. No crash recovery needed. No maintenance is required.
 ## Limitations
 
 - **Page size**: a power of 2, minimum `256` (mostly for testing), maximum `65536` bytes, default `4096` bytes.
-- **Key size**: minimum `0`, maximum ≈¼ pagesize (`1348` bytes for default 4K pagesize, `21828` bytes for 64K pagesize).
-- **Value size**: minimum `0`, maximum `2146435072` (`0x7FF00000`) bytes for maps, ≈¼ pagesize for multimaps (`1348` bytes for default 4K pagesize, `21828` bytes for 64K pagesize).
+- **Key size**: minimum `0`, maximum ≈½ pagesize (`2022` bytes for default 4K pagesize, `32742` bytes for 64K pagesize).
+- **Value size**: minimum `0`, maximum `2146435072` (`0x7FF00000`) bytes for maps, ≈½ pagesize for multimaps (`2022` bytes for default 4K pagesize, `32742` bytes for 64K pagesize).
 - **Write transaction size**: up to `1327217884` pages (`4.944272` TiB for default 4K pagesize, `79.108351` TiB for 64K pagesize).
 - **Database size**: up to `2147483648` pages (≈`8.0` TiB for default 4K pagesize, ≈`128.0` TiB for 64K pagesize).
 - **Maximum sub-databases**: `32765`.
@@ -167,9 +167,11 @@ transaction journal. No crash recovery needed. No maintenance is required.
 2. _libmdbx_ is based on [B+ tree](https://en.wikipedia.org/wiki/B%2B_tree), so access to database pages is mostly random.
 Thus SSDs provide a significant performance boost over spinning disks for large databases.
 
-3. _libmdbx_ uses [shadow paging](https://en.wikipedia.org/wiki/Shadow_paging) instead of [WAL](https://en.wikipedia.org/wiki/Write-ahead_logging). Thus syncing data to disk might be a bottleneck for write intensive workload.
+3. _libmdbx_ uses [shadow paging](https://en.wikipedia.org/wiki/Shadow_paging) instead of [WAL](https://en.wikipedia.org/wiki/Write-ahead_logging).
+Thus syncing data to disk might be a bottleneck for write intensive workload.
 
-4. _libmdbx_ uses [copy-on-write](https://en.wikipedia.org/wiki/Copy-on-write) for [snapshot isolation](https://en.wikipedia.org/wiki/Snapshot_isolation) during updates, but read transactions prevents recycling an old retired/freed pages, since it read ones. Thus altering of data during a parallel
+4. _libmdbx_ uses [copy-on-write](https://en.wikipedia.org/wiki/Copy-on-write) for [snapshot isolation](https://en.wikipedia.org/wiki/Snapshot_isolation) during updates,
+but read transactions prevents recycling an old retired/freed pages, since it read ones. Thus altering of data during a parallel
 long-lived read operation will increase the process work set, may exhaust entire free database space,
 the database can grow quickly, and result in performance degradation.
 Try to avoid long running read transactions.
@@ -200,8 +202,8 @@ the user's point of view.
 ## Added Features
 
 1. Keys could be more than 2 times longer than _LMDB_.
-  > For DB with default page size _libmdbx_ support keys up to 1300 bytes
-  > and up to 21780 bytes for 64K page size. _LMDB_ allows key size up to
+  > For DB with default page size _libmdbx_ support keys up to 2022 bytes
+  > and up to 32742 bytes for 64K page size. _LMDB_ allows key size up to
   > 511 bytes and may silently loses data with large values.
 
 2. Up to 30% faster than _LMDB_ in [CRUD](https://en.wikipedia.org/wiki/Create,_read,_update_and_delete) benchmarks.
@@ -343,6 +345,13 @@ Currently, libmdbx is only available in a
 Packages support for common Linux distributions is planned in the future,
 since release the version 1.0.
 
+## Never use tarballs nor zips automatically provided by Github !
+
+Please don't use tarballs nor zips which are automatically provided by Github.
+These archives do not contain version information and thus are unfit to build _libmdbx_.
+Instead of ones just clone the git repository, either download a tarball or zip with the properly amalgamated source core.
+Moreover, please vote for [ability of disabling auto-creation such unsuitable archives](https://github.community/t/disable-tarball).
+
 ## Source code embedding
 
 _libmdbx_ provides two official ways for integration in source code form:
@@ -362,7 +371,7 @@ The amalgamated source code could be created from the original clone of git
 repository on Linux by executing `make dist`. As a result, the desired
 set of files will be formed in the `dist` subdirectory.
 
-## Building
+## Building and Testing
 
 Both amalgamated and original source code provides build through the use
 [CMake](https://cmake.org/) or [GNU
@@ -376,10 +385,76 @@ target platform. Obviously you need building tools itself, i.e. `git`,
 and `make options` are also available for listing existing targets
 and build options respectively.
 
+The only significant specificity is that git' tags are required
+to build from complete (not amalgamated) source codes.
+Executing **`git fetch --tags --force --prune`** is enough to get ones,
+or `git fetch --unshallow --tags --prune --force` after the Github's
+[`actions/checkout@v2`](https://github.com/actions/checkout) either set **`fetch-depth: 0`** for it.
+
 So just using CMake or GNU Make in your habitual manner and feel free to
 fill an issue or make pull request in the case something will be
 unexpected or broken down.
 
+### Testing
+The amalgamated source code does not contain any tests for or several reasons.
+Please read [the explanation](https://github.com/erthink/libmdbx/issues/214#issuecomment-870717981) and don't ask to alter this.
+So for testing _libmdbx_ itself you need a full source code, i.e. the clone of a git repository, there is no option.
+
+The full source code of _libmdbx_ has a [`test` subdirectory](https://github.com/erthink/libmdbx/tree/master/test) with minimalistic test "framework".
+Actually yonder is a source code of the `mdbx_test` – console utility which has a set of command-line options that allow construct and run a reasonable enough test scenarios.
+This test utility is intended for _libmdbx_'s developers for testing library itself, but not for use by users.
+Therefore, only basic information is provided:
+
+   - There are few CRUD-based test cases (hill, TTL, nested, append, jitter, etc),
+     which can be combined to test the concurrent operations within shared database in a multi-processes environment.
+     This is the `basic` test scenario.
+   - The `Makefile` provide several self-described targets for testing: `smoke`, `test`, `check`, `memcheck`, `test-valgrind`,
+     `test-asan`, `test-leak`, `test-ubsan`, `cross-gcc`, `cross-qemu`, `gcc-analyzer`, `smoke-fault`, `smoke-singleprocess`,
+     `test-singleprocess`, 'long-test'. Please run `make --help` if doubt.
+   - In addition to the `mdbx_test` utility, there is the script [`long_stochastic.sh`](https://github.com/erthink/libmdbx/blob/master/test/long_stochastic.sh),
+     which calls `mdbx_test` by going through set of modes and options, with gradually increasing the number of operations and the size of transactions.
+     This script is used for mostly of all automatic testing, including `Makefile` targets and Continuous Integration.
+   - Brief information of available command-line options is available by `--help`.
+     However, you should dive into source code to get all, there is no option.
+
+Anyway, no matter how thoroughly the _libmdbx_ is tested, you should rely only on your own tests for a few reasons:
+
+1. Mostly of all use cases are unique.
+   So it is no warranty that your use case was properly tested, even the _libmdbx_'s tests engages stochastic approach.
+2. If there are problems, then your test on the one hand will help to verify whether you are using _libmdbx_ correctly,
+   on the other hand it will allow to reproduce the problem and insure against regression in a future.
+3. Actually you should rely on than you checked by yourself or take a risk.
+
+### Common important details
+
+#### Build reproducibility
+By default _libmdbx_ track build time via `MDBX_BUILD_TIMESTAMP` build option and macro.
+So for a [reproducible builds](https://en.wikipedia.org/wiki/Reproducible_builds) you should predefine/override it to known fixed string value.
+For instance:
+
+ - for reproducible build with make: `make MDBX_BUILD_TIMESTAMP=unknown ` ...
+ - or during configure by CMake: `cmake -DMDBX_BUILD_TIMESTAMP:STRING=unknown ` ...
+
+Of course, in addition to this, your toolchain must ensure the reproducibility of builds.
+For more information please refer to [reproducible-builds.org](https://reproducible-builds.org/).
+
+#### Containers
+There are no special traits nor quirks if you use libmdbx ONLY inside the single container.
+But in a cross-container cases or with a host-container(s) mix the two major things MUST be
+guaranteed:
+
+1. Coherence of memory mapping content and unified page cache inside OS kernel for host and all container(s) operated with a some DB.
+Basically this means must be only a single physical copy of each memory mapped DB' page in the system memory.
+
+2. Uniqueness of PID values and/or a common space for ones:
+    - for POSIX systems: PID uniqueness for all processes operated with a DB.
+      I.e. the `--pid=host` is required for run DB-aware processes inside Docker,
+      either without host interaction a `--pid=container:<name|id>` with the same name/id.
+    - for non-POSIX (i.e. Windows) systems: inter-visibility of processes handles.
+      I.e. the `OpenProcess(SYNCHRONIZE, ..., PID)` must return reasonable error,
+      including `ERROR_ACCESS_DENIED`,
+      but not the `ERROR_INVALID_PARAMETER` as for an invalid/non-existent PID.
+
 #### DSO/DLL unloading and destructors of Thread-Local-Storage objects
 When building _libmdbx_ as a shared library or use static _libmdbx_ as a
 part of another dynamic library, it is advisable to make sure that your
@@ -472,7 +547,7 @@ Please refer to the [official guide](https://developer.android.com/studio/projec
 
 ### iOS
 To build _libmdbx_ for iOS, we recommend using CMake with the
-"[toolchain file](https://cmake.org/cmake/help/latest/variable/CMAKE_TOOLCHAIN_FILE.html)"
+["toolchain file"](https://cmake.org/cmake/help/latest/variable/CMAKE_TOOLCHAIN_FILE.html)
 from the [ios-cmake](https://github.com/leetal/ios-cmake) project.
 
 <!-- section-end -->
@@ -489,12 +564,16 @@ Bindings
 
 | Runtime |  Repo  | Author |
 | ------- | ------ | ------ |
+| Haskell | [libmdbx-hs](https://hackage.haskell.org/package/libmdbx) | [Francisco Vallarino](https://github.com/fjvallarino) |
+| Python (draft) | [python-bindings](https://github.com/erthink/libmdbx/commits/python-bindings) branch | [Noel Kuntze](https://github.com/Thermi)
+| NodeJS  | [lmdbx-js](https://github.com/kriszyp/lmdbx-js) | [Kris Zyp](https://github.com/kriszyp/)
+| NodeJS  | [node-mdbx](https://www.npmjs.com/package/node-mdbx/) | [Сергей Федотов](mailto:sergey.fedotov@corp.mail.ru) |
 | Ruby    | [ruby-mdbx](https://rubygems.org/gems/mdbx/) | [Mahlon E. Smith](https://github.com/mahlonsmith) |
 | Go      | [mdbx-go](https://github.com/torquem-ch/mdbx-go) | [Alex Sharov](https://github.com/AskAlexSharov) |
 | [Nim](https://en.wikipedia.org/wiki/Nim_(programming_language)) | [NimDBX](https://github.com/snej/nimdbx) | [Jens Alfke](https://github.com/snej)
-| Rust    | [heed](https://github.com/Kerollmops/heed), [mdbx-rs](https://github.com/Kerollmops/mdbx-rs)   | [Clément Renault](https://github.com/Kerollmops) |
-| Java    | [mdbxjni](https://github.com/castortech/mdbxjni)   | [Castor Technologies](https://castortech.com/) |
-| .NET    | [mdbx.NET](https://github.com/wangjia184/mdbx.NET) | [Jerry Wang](https://github.com/wangjia184) |
+| Rust    | [libmdbx-rs](https://github.com/vorot93/libmdbx-rs)   | [Artem Vorotnikov](https://github.com/vorot93) |
+| Java   | [mdbxjni](https://github.com/castortech/mdbxjni)   | [Castor Technologies](https://castortech.com/) |
+| .NET (obsolete)   | [mdbx.NET](https://github.com/wangjia184/mdbx.NET) | [Jerry Wang](https://github.com/wangjia184) |
 
 <!-- section-end -->
 
@@ -603,7 +682,9 @@ records.
  execution time of transactions. Each interval shows minimal and maximum
  execution time, cross marks standard deviation.
 
-**1,000,000 transactions in async-write mode**. In case of a crash all data is consistent and conforms to the one of last successful transactions, but lost transaction count is much higher than in
+**1,000,000 transactions in async-write mode**.
+In case of a crash all data is consistent and conforms to the one of last successful transactions,
+but lost transaction count is much higher than in
 lazy-write mode. All DB engines in this mode do as little writes as
 possible on persistent storage. _libmdbx_ uses
 [msync(MS_ASYNC)](https://linux.die.net/man/2/msync) in this mode.

appveyor.yml

@@ -1,4 +1,4 @@
-version: 0.10.0.{build}
+version: 0.11.2.{build}
 
 environment:
   matrix:
@@ -52,8 +52,8 @@ matrix:
       configuration: Release
 
 # Enable RDP for troubleshooting
-init:
-  - ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
+#init:
+#  - ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
 
 before_build:
 - git clean -x -f -d

cmake/compiler.cmake

@@ -13,9 +13,14 @@
 ##  limitations under the License.
 ##
 
-cmake_minimum_required(VERSION 3.8.2)
+if(CMAKE_VERSION VERSION_LESS 3.12)
+  cmake_minimum_required(VERSION 3.8.2)
+else()
+  cmake_minimum_required(VERSION 3.12)
+endif()
+
 cmake_policy(PUSH)
-cmake_policy(VERSION 3.8.2)
+cmake_policy(VERSION ${CMAKE_MINIMUM_REQUIRED_VERSION})
 
 if(CMAKE_VERSION MATCHES ".*MSVC.*" AND CMAKE_VERSION VERSION_LESS 3.16)
   message(FATAL_ERROR "CMake from MSVC kit is unfit! "
@@ -286,21 +291,21 @@ if(CMAKE_COMPILER_IS_GNU${CMAKE_PRIMARY_LANG})
 
     set(gcc_suffix "")
     if(gcc_collect_valid AND gcc_collect)
-      string(REGEX MATCH "^(.*cc)(-.+)$" gcc_suffix_valid ${gcc_collect})
+      string(REGEX MATCH "^(.*(cc|\\+\\+))(-.+)$" gcc_suffix_valid ${gcc_collect})
       if(gcc_suffix_valid)
-        string(REGEX MATCH "^(.*cc)(-.+)$" "\\2" gcc_suffix ${gcc_collect})
+        string(REGEX REPLACE "^(.*(cc|\\+\\+))(-.+)$" "\\3" gcc_suffix ${gcc_collect})
       endif()
     endif()
 
     get_filename_component(gcc_dir ${CMAKE_${CMAKE_PRIMARY_LANG}_COMPILER} DIRECTORY)
     if(NOT CMAKE_GCC_AR)
-      find_program(CMAKE_GCC_AR NAMES gcc${gcc_suffix}-ar gcc-ar${gcc_suffix} PATHS ${gcc_dir} NO_DEFAULT_PATH)
+      find_program(CMAKE_GCC_AR NAMES "gcc${gcc_suffix}-ar" "gcc-ar${gcc_suffix}" PATHS "${gcc_dir}" NO_DEFAULT_PATH)
     endif()
     if(NOT CMAKE_GCC_NM)
-      find_program(CMAKE_GCC_NM NAMES gcc${gcc_suffix}-nm gcc-nm${gcc_suffix} PATHS ${gcc_dir} NO_DEFAULT_PATH)
+      find_program(CMAKE_GCC_NM NAMES "gcc${gcc_suffix}-nm" "gcc-nm${gcc_suffix}" PATHS "${gcc_dir}" NO_DEFAULT_PATH)
     endif()
     if(NOT CMAKE_GCC_RANLIB)
-      find_program(CMAKE_GCC_RANLIB NAMES gcc${gcc_suffix}-ranlib gcc-ranlib${gcc_suffix} PATHS ${gcc_dir} NO_DEFAULT_PATH)
+      find_program(CMAKE_GCC_RANLIB NAMES "gcc${gcc_suffix}-ranlib" "gcc-ranlib${gcc_suffix}" PATHS "${gcc_dir}" NO_DEFAULT_PATH)
     endif()
 
     unset(gcc_dir)
@@ -342,30 +347,40 @@ if(CMAKE_COMPILER_IS_CLANG)
       OUTPUT_VARIABLE clang_search_dirs RESULT_VARIABLE clang_probe_result ERROR_QUIET)
 
     unset(clang_bindirs)
+    unset(clang_bindirs_x)
     unset(clang_libdirs)
+    unset(clang_libdirs_x)
     if(clang_probe_result EQUAL 0)
-        string(REGEX MATCH "(^|\n.*)(.*programs: =)([^\n]+)((\n.*)|$)" regexp_valid ${clang_search_dirs})
-        if(regexp_valid)
-          string(REGEX REPLACE "(^|\n.*)(.*programs: =)([^\n]+)((\n.*)|$)" "\\3" list ${clang_search_dirs})
-          string(REPLACE ":" ";" list "${list}")
-          #set(clang_bindirs "")
-          foreach(dir IN LISTS list)
-            get_filename_component(dir "${dir}" REALPATH)
+      string(REGEX MATCH "(^|\n.*)(.*programs: =)([^\n]+)((\n.*)|$)" regexp_valid ${clang_search_dirs})
+      if(regexp_valid)
+        string(REGEX REPLACE "(^|\n.*)(.*programs: =)([^\n]+)((\n.*)|$)" "\\3" list ${clang_search_dirs})
+        string(REPLACE ":" ";" list "${list}")
+        foreach(dir IN LISTS list)
+          get_filename_component(dir "${dir}" REALPATH)
+          if(dir MATCHES ".*llvm.*" OR dir MATCHES ".*clang.*")
             list(APPEND clang_bindirs "${dir}")
-          endforeach()
-          list(REMOVE_DUPLICATES clang_bindirs)
-        endif()
-        string(REGEX MATCH "(^|\n.*)(.*libraries: =)([^\n]+)((\n.*)|$)" regexp_valid ${clang_search_dirs})
-        if(regexp_valid)
-          string(REGEX REPLACE "(^|\n.*)(.*libraries: =)([^\n]+)((\n.*)|$)" "\\3" list ${clang_search_dirs})
-          string(REPLACE ":" ";" list "${list}")
-          #set(clang_libdirs "")
-          foreach(dir IN LISTS list)
-            get_filename_component(dir "${dir}" REALPATH)
+          else()
+            list(APPEND clang_bindirs_x "${dir}")
+          endif()
+        endforeach()
+        list(APPEND clang_bindirs "${clang_bindirs_x}")
+        list(REMOVE_DUPLICATES clang_bindirs)
+      endif()
+      string(REGEX MATCH "(^|\n.*)(.*libraries: =)([^\n]+)((\n.*)|$)" regexp_valid ${clang_search_dirs})
+      if(regexp_valid)
+        string(REGEX REPLACE "(^|\n.*)(.*libraries: =)([^\n]+)((\n.*)|$)" "\\3" list ${clang_search_dirs})
+        string(REPLACE ":" ";" list "${list}")
+        foreach(dir IN LISTS list)
+          get_filename_component(dir "${dir}" REALPATH)
+          if(dir MATCHES ".*llvm.*" OR dir MATCHES ".*clang.*")
             list(APPEND clang_libdirs "${dir}")
-          endforeach()
-          list(REMOVE_DUPLICATES clang_libdirs)
-        endif()
+          else()
+            list(APPEND clang_libdirs_x "${dir}")
+          endif()
+        endforeach()
+        list(APPEND clang_libdirs "${clang_libdirs_x}")
+        list(REMOVE_DUPLICATES clang_libdirs)
+      endif()
     else()
       get_filename_component(clang_bindirs ${CMAKE_${CMAKE_PRIMARY_LANG}_COMPILER} DIRECTORY)
       if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")

cmake/profile.cmake

@@ -13,9 +13,14 @@
 ##  limitations under the License.
 ##
 
-cmake_minimum_required(VERSION 3.8.2)
+if(CMAKE_VERSION VERSION_LESS 3.12)
+  cmake_minimum_required(VERSION 3.8.2)
+else()
+  cmake_minimum_required(VERSION 3.12)
+endif()
+
 cmake_policy(PUSH)
-cmake_policy(VERSION 3.8.2)
+cmake_policy(VERSION ${CMAKE_MINIMUM_REQUIRED_VERSION})
 
 include(CheckLibraryExists)
 check_library_exists(gcov __gcov_flush "" HAVE_GCOV)

cmake/utils.cmake

@@ -13,9 +13,14 @@
 ##  limitations under the License.
 ##
 
-cmake_minimum_required(VERSION 3.8.2)
+if(CMAKE_VERSION VERSION_LESS 3.12)
+  cmake_minimum_required(VERSION 3.8.2)
+else()
+  cmake_minimum_required(VERSION 3.12)
+endif()
+
 cmake_policy(PUSH)
-cmake_policy(VERSION 3.8.2)
+cmake_policy(VERSION ${CMAKE_MINIMUM_REQUIRED_VERSION})
 
 macro(add_compile_flags languages)
   foreach(_lang ${languages})
@@ -173,7 +178,10 @@ macro(fetch_version name source_root_directory parent_scope)
     set(${name}_GIT_REVISION 0)
 
     # Try to get version from VERSION file
-    set(version_file "${source_root_directory}/VERSION")
+    set(version_file "${source_root_directory}/VERSION.txt")
+    if(NOT EXISTS "${version_file}")
+      set(version_file "${source_root_directory}/VERSION")
+    endif()
     if(EXISTS "${version_file}")
       file(STRINGS "${version_file}" ${name}_VERSION LIMIT_COUNT 1 LIMIT_INPUT 42)
     endif()

mdbx.h

@@ -361,6 +361,12 @@ typedef mode_t mdbx_mode_t;
 #define LIBMDBX_INLINE_API(TYPE, NAME, ARGS) static __inline TYPE NAME ARGS
 #endif /* LIBMDBX_INLINE_API */
 
+/** \brief Converts a macro argument into a string constant. */
+#ifndef MDBX_STRINGIFY
+#define MDBX_STRINGIFY_HELPER(x) #x
+#define MDBX_STRINGIFY(x) MDBX_STRINGIFY_HELPER(x)
+#endif /* MDBX_STRINGIFY */
+
 /*----------------------------------------------------------------------------*/
 
 #ifndef __cplusplus
@@ -387,7 +393,8 @@ typedef mode_t mdbx_mode_t;
 #define MDBX_CXX01_CONSTEXPR __inline
 #define MDBX_CXX01_CONSTEXPR_VAR const
 #elif !defined(DOXYGEN) &&                                                     \
-    (!defined(__cpp_constexpr) || __cpp_constexpr < 200704L ||                 \
+    ((__cplusplus < 201103L && defined(__cpp_constexpr) &&                     \
+      __cpp_constexpr < 200704L) ||                                            \
      (defined(__LCC__) && __LCC__ < 124) ||                                    \
      (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 407) &&          \
       !defined(__clang__) && !defined(__LCC__)) ||                             \
@@ -404,7 +411,7 @@ typedef mode_t mdbx_mode_t;
 #define MDBX_CXX11_CONSTEXPR __inline
 #define MDBX_CXX11_CONSTEXPR_VAR const
 #elif !defined(DOXYGEN) &&                                                     \
-    (!defined(__cpp_constexpr) || __cpp_constexpr < 201304 ||                  \
+    (!defined(__cpp_constexpr) || __cpp_constexpr < 201304L ||                 \
      (defined(__LCC__) && __LCC__ < 124) ||                                    \
      (defined(__GNUC__) && __GNUC__ < 6 && !defined(__clang__) &&              \
       !defined(__LCC__)) ||                                                    \
@@ -454,6 +461,25 @@ typedef mode_t mdbx_mode_t;
 #endif
 #endif /* MDBX_PRINTF_ARGS */
 
+#if defined(DOXYGEN) ||                                                        \
+    (defined(__cplusplus) && __cplusplus >= 201603 &&                          \
+     __has_cpp_attribute(maybe_unused) &&                                      \
+     __has_cpp_attribute(maybe_unused) >= 201603) ||                           \
+    (!defined(__cplusplus) && defined(__STDC_VERSION__) &&                     \
+     __STDC_VERSION__ > 202005L)
+#define MDBX_MAYBE_UNUSED [[maybe_unused]]
+#elif defined(__GNUC__) || __has_attribute(__unused__)
+#define MDBX_MAYBE_UNUSED __attribute__((__unused__))
+#else
+#define MDBX_MAYBE_UNUSED
+#endif /* MDBX_MAYBE_UNUSED */
+
+#if __has_attribute(no_sanitize)
+#define MDBX_NOSANITIZE_ENUM __attribute((__no_sanitize__("enum")))
+#else
+#define MDBX_NOSANITIZE_ENUM
+#endif /* MDBX_NOSANITIZE_ENUM */
+
 /* Oh, below are some songs and dances since:
  *  - C++ requires explicit definition of the necessary operators.
  *  - the proper implementation of DEFINE_ENUM_FLAG_OPERATORS for C++ required
@@ -479,28 +505,40 @@ typedef mode_t mdbx_mode_t;
 /// used to define flags (based on Microsoft's DEFINE_ENUM_FLAG_OPERATORS).
 #define DEFINE_ENUM_FLAG_OPERATORS(ENUM)                                       \
   extern "C++" {                                                               \
-  MDBX_CXX01_CONSTEXPR ENUM operator|(ENUM a, ENUM b) {                        \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX01_CONSTEXPR ENUM operator|(ENUM a, ENUM b) {   \
     return ENUM(unsigned(a) | unsigned(b));                                    \
   }                                                                            \
-  MDBX_CXX14_CONSTEXPR ENUM &operator|=(ENUM &a, ENUM b) { return a = a | b; } \
-  MDBX_CXX01_CONSTEXPR ENUM operator&(ENUM a, ENUM b) {                        \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX14_CONSTEXPR ENUM &operator|=(ENUM &a,          \
+                                                             ENUM b) {         \
+    return a = a | b;                                                          \
+  }                                                                            \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX01_CONSTEXPR ENUM operator&(ENUM a, ENUM b) {   \
     return ENUM(unsigned(a) & unsigned(b));                                    \
   }                                                                            \
-  MDBX_CXX01_CONSTEXPR ENUM operator&(ENUM a, unsigned b) {                    \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX01_CONSTEXPR ENUM operator&(ENUM a,             \
+                                                           unsigned b) {       \
     return ENUM(unsigned(a) & b);                                              \
   }                                                                            \
-  MDBX_CXX01_CONSTEXPR ENUM operator&(unsigned a, ENUM b) {                    \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX01_CONSTEXPR ENUM operator&(unsigned a,         \
+                                                           ENUM b) {           \
     return ENUM(a & unsigned(b));                                              \
   }                                                                            \
-  MDBX_CXX14_CONSTEXPR ENUM &operator&=(ENUM &a, ENUM b) { return a = a & b; } \
-  MDBX_CXX14_CONSTEXPR ENUM &operator&=(ENUM &a, unsigned b) {                 \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX14_CONSTEXPR ENUM &operator&=(ENUM &a,          \
+                                                             ENUM b) {         \
+    return a = a & b;                                                          \
+  }                                                                            \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX14_CONSTEXPR ENUM &operator&=(ENUM &a,          \
+                                                             unsigned b) {     \
     return a = a & b;                                                          \
   }                                                                            \
   MDBX_CXX01_CONSTEXPR unsigned operator~(ENUM a) { return ~unsigned(a); }     \
-  MDBX_CXX01_CONSTEXPR ENUM operator^(ENUM a, ENUM b) {                        \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX01_CONSTEXPR ENUM operator^(ENUM a, ENUM b) {   \
     return ENUM(unsigned(a) ^ unsigned(b));                                    \
   }                                                                            \
-  MDBX_CXX14_CONSTEXPR ENUM &operator^=(ENUM &a, ENUM b) { return a = a ^ b; } \
+  MDBX_NOSANITIZE_ENUM MDBX_CXX14_CONSTEXPR ENUM &operator^=(ENUM &a,          \
+                                                             ENUM b) {         \
+    return a = a ^ b;                                                          \
+  }                                                                            \
   }
 #else /* __cplusplus */
 /* nope for C since it always allows these operators for enums */
@@ -531,9 +569,9 @@ typedef mode_t mdbx_mode_t;
 extern "C" {
 #endif
 
-/* MDBX version 0.10.x */
+/* MDBX version 0.11.x */
 #define MDBX_VERSION_MAJOR 0
-#define MDBX_VERSION_MINOR 10
+#define MDBX_VERSION_MINOR 11
 
 #ifndef LIBMDBX_API
 #if defined(LIBMDBX_EXPORTS)
@@ -772,6 +810,10 @@ enum MDBX_log_level_t {
       and all other log-messages */
   MDBX_LOG_EXTRA = 7,
 
+#ifdef ENABLE_UBSAN
+  MDBX_LOG_MAX = 7 /* avoid UBSAN false-positive trap by a tests */,
+#endif /* ENABLE_UBSAN */
+
   /** for \ref mdbx_setup_debug() only: Don't change current settings */
   MDBX_LOG_DONTCHANGE = -1
 };
@@ -785,6 +827,8 @@ typedef enum MDBX_log_level_t MDBX_log_level_t;
  * effect, but `MDBX_DBG_ASSERT`, `MDBX_DBG_AUDIT` and `MDBX_DBG_JITTER` only if
  * libmdbx builded with \ref MDBX_DEBUG. */
 enum MDBX_debug_flags_t {
+  MDBX_DBG_NONE = 0,
+
   /** Enable assertion checks.
    * Requires build with \ref MDBX_DEBUG > 0 */
   MDBX_DBG_ASSERT = 1,
@@ -807,6 +851,11 @@ enum MDBX_debug_flags_t {
   /** Allow read and write transactions overlapping for the same thread */
   MDBX_DBG_LEGACY_OVERLAP = 32,
 
+#ifdef ENABLE_UBSAN
+  MDBX_DBG_MAX = ((unsigned)MDBX_LOG_MAX) << 16 |
+                 63 /* avoid UBSAN false-positive trap by a tests */,
+#endif /* ENABLE_UBSAN */
+
   /** for mdbx_setup_debug() only: Don't change current settings */
   MDBX_DBG_DONTCHANGE = -1
 };
@@ -1334,10 +1383,10 @@ DEFINE_ENUM_FLAG_OPERATORS(MDBX_txn_flags_t)
 enum MDBX_db_flags_t {
   MDBX_DB_DEFAULTS = 0,
 
-  /** Use reverse string keys */
+  /** Use reverse string comparison for keys. */
   MDBX_REVERSEKEY = UINT32_C(0x02),
 
-  /** Use sorted duplicates, i.e. allow multi-values */
+  /** Use sorted duplicates, i.e. allow multi-values for a keys. */
   MDBX_DUPSORT = UINT32_C(0x04),
 
   /** Numeric keys in native byte order either uint32_t or uint64_t. The keys
@@ -1345,18 +1394,19 @@ enum MDBX_db_flags_t {
    * arguments. */
   MDBX_INTEGERKEY = UINT32_C(0x08),
 
-  /** With \ref MDBX_DUPSORT; sorted dup items have fixed size */
+  /** With \ref MDBX_DUPSORT; sorted dup items have fixed size. The data values
+   * must all be of the same size. */
   MDBX_DUPFIXED = UINT32_C(0x10),
 
   /** With \ref MDBX_DUPSORT and with \ref MDBX_DUPFIXED; dups are fixed size
-   * \ref MDBX_INTEGERKEY -style integers. The data values must all be of the
-   * same size and must be aligned while passing as arguments. */
+   * like \ref MDBX_INTEGERKEY -style integers. The data values must all be of
+   * the same size and must be aligned while passing as arguments. */
   MDBX_INTEGERDUP = UINT32_C(0x20),
 
-  /** With \ref MDBX_DUPSORT; use reverse string comparison */
+  /** With \ref MDBX_DUPSORT; use reverse string comparison for data values. */
   MDBX_REVERSEDUP = UINT32_C(0x40),
 
-  /** Create DB if not already existing */
+  /** Create DB if not already existing. */
   MDBX_CREATE = UINT32_C(0x40000),
 
   /** Opens an existing sub-database created with unknown flags.
@@ -1687,7 +1737,7 @@ enum MDBX_error_t {
 #ifdef ENODATA
   MDBX_ENODATA = ENODATA,
 #else
-  MDBX_ENODATA = -1,
+  MDBX_ENODATA = 9919 /* for compatibility with LLVM's C++ libraries/headers */,
 #endif /* ENODATA */
   MDBX_EINVAL = EINVAL,
   MDBX_EACCESS = EACCES,
@@ -2275,7 +2325,8 @@ struct MDBX_envinfo {
   /** Statistics of page operations.
    * \details Overall statistics of page operations of all (running, completed
    * and aborted) transactions in the current multi-process session (since the
-   * first process opened the database). */
+   * first process opened the database after everyone had previously closed it).
+   */
   struct {
     uint64_t newly;   /**< Quantity of a new pages added */
     uint64_t cow;     /**< Quantity of pages copied for update */
@@ -3235,9 +3286,11 @@ struct MDBX_commit_latency {
   uint32_t gc;
   /** \brief Duration of internal audit if enabled. */
   uint32_t audit;
-  /** \brief Duration of writing dirty/modified data pages. */
+  /** \brief Duration of writing dirty/modified data pages to a filesystem,
+   * i.e. the summary duration of a `write()` syscalls during commit. */
   uint32_t write;
-  /** \brief Duration of syncing written data to the dist/storage. */
+  /** \brief Duration of syncing written data to the disk/storage, i.e.
+   * the duration of a `fdatasync()` or a `msync()` syscall during commit. */
   uint32_t sync;
   /** \brief Duration of transaction ending (releasing resources). */
   uint32_t ending;
@@ -3451,7 +3504,23 @@ LIBMDBX_API int mdbx_canary_get(const MDBX_txn *txn, MDBX_canary *canary);
 /** \brief A callback function used to compare two keys in a database
  * \ingroup c_crud
  * \see mdbx_cmp() \see mdbx_get_keycmp()
- * \see mdbx_get_datacmp \see mdbx_dcmp() */
+ * \see mdbx_get_datacmp \see mdbx_dcmp()
+ *
+ * \anchor avoid_custom_comparators
+ * It is recommend not using custom comparison functions, but instead
+ * converting the keys to one of the forms that are suitable for built-in
+ * comparators (for instance take look to the \ref value2key).
+ * The reasons to not using custom comparators are:
+ *   - The order of records could not be validated without your code.
+ *     So `mdbx_chk` utility will reports "wrong order" errors
+ *     and the `-i` option is required to suppress ones.
+ *   - A records could not be ordered or sorted without your code.
+ *     So `mdbx_load` utility should be used with `-a` option to preserve
+ *     input data order.
+ *   - However, the custom comparators feature will never be removed.
+ *     You have been warned but still can use custom comparators knowing
+ *     about the issues noted above. In this case you should ignore `deprecated`
+ *     warnings or define `MDBX_DEPRECATED` macro to empty to avoid ones. */
 typedef int(MDBX_cmp_func)(const MDBX_val *a,
                            const MDBX_val *b) MDBX_CXX17_NOEXCEPT;
 
@@ -3528,16 +3597,7 @@ typedef int(MDBX_cmp_func)(const MDBX_val *a,
  *
  * For \ref mdbx_dbi_open_ex() additional arguments allow you to set custom
  * comparison functions for keys and values (for multimaps).
- * However, I recommend not using custom comparison functions, but instead
- * converting the keys to one of the forms that are suitable for built-in
- * comparators (for instance take look to the \ref value2key).
- * The reasons to not using custom comparators are:
- *   - The order of records could not be validated without your code.
- *     So `mdbx_chk` utility will reports "wrong order" errors
- *     and the `-i` option is required to ignore ones.
- *   - A records could not be ordered or sorted without your code.
- *     So mdbx_load utility should be used with `-a` option to preserve
- *     input data order.
+ * \see avoid_custom_comparators
  *
  * \returns A non-zero error value on failure and 0 on success,
  *          some possible errors are:
@@ -3554,8 +3614,10 @@ typedef int(MDBX_cmp_func)(const MDBX_val *a,
 LIBMDBX_API int mdbx_dbi_open(MDBX_txn *txn, const char *name,
                               MDBX_db_flags_t flags, MDBX_dbi *dbi);
 
-/** \deprecated Please avoid using custom comparators
- *              and use mdbx_dbi_open() instead.
+/** \deprecated Please
+ * \ref avoid_custom_comparators "avoid using custom comparators" and use
+ * \ref mdbx_dbi_open() instead.
+ *
  * \ingroup c_dbi
  *
  * \param [in] txn    transaction handle returned by \ref mdbx_txn_begin().
@@ -3571,7 +3633,9 @@ MDBX_DEPRECATED LIBMDBX_API int
 mdbx_dbi_open_ex(MDBX_txn *txn, const char *name, MDBX_db_flags_t flags,
                  MDBX_dbi *dbi, MDBX_cmp_func *keycmp, MDBX_cmp_func *datacmp);
 
-/** \defgroup value2key Value-to-Key functions to avoid custom comparators
+/** \defgroup value2key Value-to-Key functions
+ * \brief Value-to-Key functions to
+ * \ref avoid_custom_comparators "avoid using custom comparators"
  * \see key2value
  * @{
  *
@@ -3606,7 +3670,9 @@ MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_INLINE_API(uint32_t, mdbx_key_from_int32,
 }
 /** @} */
 
-/** \defgroup key2value Key-to-Value functions to avoid custom comparators
+/** \defgroup key2value Key-to-Value functions
+ * \brief Key-to-Value functions to
+ * \ref avoid_custom_comparators "avoid using custom comparators"
  * \see value2key
  * @{ */
 MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int64_t
@@ -4542,6 +4608,7 @@ LIBMDBX_API int mdbx_dbi_sequence(MDBX_txn *txn, MDBX_dbi dbi, uint64_t *result,
 
 /** \brief Compare two keys according to a particular database.
  * \ingroup c_crud
+ * \see MDBX_cmp_func
  *
  * This returns a comparison as if the two data items were keys in the
  * specified database.
@@ -4566,6 +4633,7 @@ mdbx_get_keycmp(MDBX_db_flags_t flags);
 
 /** \brief Compare two data items according to a particular database.
  * \ingroup c_crud
+ * \see MDBX_cmp_func
  *
  * This returns a comparison as if the two items were data items of the
  * specified database.

packages/buildroot/0001-package-libmdbx-new-package-library-database.patch

@@ -1,10 +1,9 @@
-From 7834ae8fc834f5f7b98d45703079cd94e5402ed6 Mon Sep 17 00:00:00 2001
+From f732fc79456f3b296543ab2625d35eeef2655618 Mon Sep 17 00:00:00 2001
 From: Leonid Yuriev <leo@yuriev.ru>
-Date: Fri, 27 Nov 2020 16:31:12 +0300
-Cc: Heiko Thiery <heiko.thiery@gmail.com>, Thomas Petazzoni <thomas.petazzoni@bootlin.com>, Leonid Yuriev <leo@yuriev.ru
-Subject: [PATCH v5 1/1] package/libmdbx: new package (library/database).
+Date: Sun, 24 Oct 2021 20:13:33 +0300
+Subject: [PATCH] package/libmdbx: new package (library/database).
 
-This patch adds libmdbx v0.9.2:
+This patch adds libmdbx v0.11.1:
  - libmdbx is one of the fastest compact embeddable key-value ACID database.
  - libmdbx has a specific set of properties and capabilities,
    focused on creating unique lightweight solutions.
@@ -13,44 +12,14 @@ This patch adds libmdbx v0.9.2:
  - https://github.com/erthink/libmdbx
 
 Signed-off-by: Leonid Yuriev <leo@yuriev.ru>
-
----
-Changes v1 -> v2:
-  - libmdbx version v0.8.2 -> v0.9.1 (released 2020-09-30)
-
-Changes v2 -> v3:
-  - removed outcommented stuff (suggested by Heiko Thiery).
-  - cleaned up and simplified the makefile (suggested by Heiko Thiery).
-  - added patch for C++ header installation.
-  - added patch with fix minor copy&paste typo.
-  - added patch with pthread workaround for buggy toolchain/cmake/buildroot.
-  - added patch for `pthread_yield()`.
-  - passed `utils/check-package package/libmdbx/*` (suggested by Heiko Thiery)
-  - passed `utils/test-pkg -a -p libmdbx`,
-    except w/o threads & w/o MMU (suggested by Heiko Thiery).
-
-Changes v3 -> v4:
-  - fix passing BR2_PACKAGE_LIBMDBX_TOOLS option to cmake.
-  - fix using `depend on` instead of `select`,
-    and add `comment` for C++ toolchain (suggested by Heiko Thiery).
-  - fix minor help typo.
-
-Changes v4 -> v5:
-  - libmdbx version v0.9.1 -> v0.9.2 (released 2020-11-27)
-  - dropped all patch since not needed.
-  - cosmetic changes (suggested by Thomas Petazzoni <thomas.petazzoni@bootlin.com>).
-  - added dependence of BR2_TOOLCHAIN_HAS_SYNC_4 (suggested by Thomas Petazzoni <thomas.petazzoni@bootlin.com>).
-  - added dependence of !BR2_TOOLCHAIN_HAS_GCC_BUG_64735 (suggested by Thomas Petazzoni <thomas.petazzoni@bootlin.com>).
-  - take in account the BR2_SHARED_STATIC_LIBS (suggested by Thomas Petazzoni <thomas.petazzoni@bootlin.com>).
-
-Signed-off-by: Leonid Yuriev <leo@yuriev.ru>
+Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
 ---
  DEVELOPERS                   |  3 +++
  package/Config.in            |  1 +
  package/libmdbx/Config.in    | 45 ++++++++++++++++++++++++++++++++++++
  package/libmdbx/libmdbx.hash |  5 ++++
- package/libmdbx/libmdbx.mk   | 33 ++++++++++++++++++++++++++
- 5 files changed, 87 insertions(+)
+ package/libmdbx/libmdbx.mk   | 42 +++++++++++++++++++++++++++++++++
+ 5 files changed, 96 insertions(+)
  create mode 100644 package/libmdbx/Config.in
  create mode 100644 package/libmdbx/libmdbx.hash
  create mode 100644 package/libmdbx/libmdbx.mk
@@ -134,28 +103,28 @@ index 0000000000..d13f73938f
 +		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
 diff --git a/package/libmdbx/libmdbx.hash b/package/libmdbx/libmdbx.hash
 new file mode 100644
-index 0000000000..0d3501f1d9
+index 0000000000..c8b50f9ac3
 --- /dev/null
 +++ b/package/libmdbx/libmdbx.hash
 @@ -0,0 +1,5 @@
 +# Hashes from: https://github.com/erthink/libmdbx/releases/
-+sha256  c35cc53d66d74ebfc86e39441ba26276541ac7892bf91dba1e70c83665a02767  libmdbx-amalgamated-0.9.2.tar.gz
++sha256  f954ba8c9768914a92c2b46aac0d66bec674dbb4d7b0f01e362ea2921746ddaa  libmdbx-amalgamated-0.11.1.tar.gz
 +
 +# Locally calculated
 +sha256  310fe25c858a9515fc8c8d7d1f24a67c9496f84a91e0a0e41ea9975b1371e569  LICENSE
 diff --git a/package/libmdbx/libmdbx.mk b/package/libmdbx/libmdbx.mk
 new file mode 100644
-index 0000000000..f3720130ec
+index 0000000000..02d00b1a5a
 --- /dev/null
 +++ b/package/libmdbx/libmdbx.mk
-@@ -0,0 +1,33 @@
+@@ -0,0 +1,42 @@
 +################################################################################
 +#
 +# libmdbx
 +#
 +################################################################################
 +
-+LIBMDBX_VERSION = 0.9.2
++LIBMDBX_VERSION = 0.11.1
 +LIBMDBX_SOURCE = libmdbx-amalgamated-$(LIBMDBX_VERSION).tar.gz
 +LIBMDBX_SITE = https://github.com/erthink/libmdbx/releases/download/v$(LIBMDBX_VERSION)
 +LIBMDBX_SUPPORTS_IN_SOURCE_BUILD = NO
@@ -165,7 +134,12 @@ index 0000000000..f3720130ec
 +LIBMDBX_STRIP_COMPONENTS = 0
 +LIBMDBX_INSTALL_STAGING = YES
 +
-+LIBMDBX_CONF_OPTS = -DMDBX_INSTALL_MANPAGES=OFF -DBUILD_FOR_NATIVE_CPU=OFF \
++# Set CMAKE_BUILD_TYPE to Release to remove -Werror and avoid a build failure
++# with glibc < 2.12
++LIBMDBX_CONF_OPTS = \
++	-DCMAKE_BUILD_TYPE=Release \
++	-DMDBX_INSTALL_MANPAGES=OFF \
++	-DBUILD_FOR_NATIVE_CPU=OFF \
 +	-DMDBX_BUILD_CXX=$(if $(BR2_PACKAGE_LIBMDBX_CXX),ON,OFF) \
 +	-DMDBX_BUILD_TOOLS=$(if $(BR2_PACKAGE_LIBMDBX_TOOLS),ON,OFF)
 +
@@ -176,12 +150,16 @@ index 0000000000..f3720130ec
 +endif
 +
 +ifeq ($(BR2_SHARED_LIBS)$(BR2_SHARED_STATIC_LIBS),y)
-+LIBMDBX_CONF_OPTS += -DMDBX_BUILD_SHARED_LIBRARY=ON -DMDBX_LINK_TOOLS_NONSTATIC=ON
++LIBMDBX_CONF_OPTS += \
++	-DMDBX_BUILD_SHARED_LIBRARY=ON \
++	-DMDBX_LINK_TOOLS_NONSTATIC=ON
 +else
-+LIBMDBX_CONF_OPTS += -DMDBX_BUILD_SHARED_LIBRARY=OFF -DMDBX_LINK_TOOLS_NONSTATIC=OFF
++LIBMDBX_CONF_OPTS += \
++	-DMDBX_BUILD_SHARED_LIBRARY=OFF \
++	-DMDBX_LINK_TOOLS_NONSTATIC=OFF
 +endif
 +
 +$(eval $(cmake-package))
 -- 
-2.29.2
+2.33.1
 

packages/buildroot/v5-0000-cover-letter-package-libmdbx.patch

@@ -1,219 +0,0 @@
-From 0bf9d06e8b090e2d9783d03074f3752ed708f6cf Mon Sep 17 00:00:00 2001
-From: Leonid Yuriev <leo@yuriev.ru>
-Date: Fri, 27 Nov 2020 16:31:12 +0300
-Cc: Heiko Thiery <heiko.thiery@gmail.com>
-Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
-Subject: [PATCH v5 0/1] cover letter for package/libmdbx: new package (library/database)
-
-This patch adds libmdbx v0.9.2 and below is a brief overview of libmdbx.
-Please merge.
-
-Regards,
-Leonid.
-
---
-
-libmdbx is an extremely fast, compact, powerful, embedded, transactional
-key-value database, with permissive license. libmdbx has a specific set
-of properties and capabilities, focused on creating unique lightweight
-solutions.
-
-Historically, libmdbx (MDBX) is a deeply revised and extended descendant
-of the legendary LMDB (Lightning Memory-Mapped Database). libmdbx
-inherits all benefits from LMDB, but resolves some issues and adds a set
-of improvements.
-
-According to developers, for now libmdbx surpasses the LMDB in terms of
-reliability, features and performance.
-
-
-The most important differences MDBX from LMDB:
-==============================================
-
-1. More attention is paid to the quality of the code, to an
-"unbreakability" of the API, to testing and automatic checks (i.e.
-sanitizers, etc). So there:
- - more control during operation;
- - more checking parameters, internal audit of database structures;
- - no warnings from compiler;
- - no issues from ASAN, UBSAN, Valgrind, Coverity;
- - etc.
-
-2. Keys could be more than 2 times longer than LMDB.
-
-3. Up to 20% faster than LMDB in CRUD benchmarks.
-
-4. Automatic on-the-fly database size adjustment,
-both increment and reduction.
-
-5. Automatic continuous zero-overhead database compactification.
-
-6. The same database format for 32- and 64-bit builds.
-
-7. LIFO policy for Garbage Collection recycling (this can significantly
-increase write performance due write-back disk cache up to several times
-in a best case scenario).
-
-8. Range query estimation.
-
-9. Utility for checking the integrity of the database structure with
-some recovery capabilities.
-
-For more info please refer:
- - https://github.com/erthink/libmdbx for source code and README.
- - https://erthink.github.io/libmdbx for API description.
-
---
-
-MDBX is a Btree-based database management library modeled loosely on the
-BerkeleyDB API, but much simplified. The entire database (aka
-"environment") is exposed in a memory map, and all data fetches return
-data directly from the mapped memory, so no malloc's or memcpy's occur
-during data fetches. As such, the library is extremely simple because it
-requires no page caching layer of its own, and it is extremely high
-performance and memory-efficient. It is also fully transactional with
-full ACID semantics, and when the memory map is read-only, the database
-integrity cannot be corrupted by stray pointer writes from application
-code.
-
-The library is fully thread-aware and supports concurrent read/write
-access from multiple processes and threads. Data pages use a
-copy-on-write strategy so no active data pages are ever overwritten,
-which also provides resistance to corruption and eliminates the need of
-any special recovery procedures after a system crash. Writes are fully
-serialized; only one write transaction may be active at a time, which
-guarantees that writers can never deadlock. The database structure is
-multi-versioned so readers run with no locks; writers cannot block
-readers, and readers don't block writers.
-
-Unlike other well-known database mechanisms which use either write-ahead
-transaction logs or append-only data writes, MDBX requires no
-maintenance during operation. Both write-ahead loggers and append-only
-databases require periodic checkpointing and/or compaction of their log
-or database files otherwise they grow without bound. MDBX tracks
-retired/freed pages within the database and re-uses them for new write
-operations, so the database size does not grow without bound in normal
-use.
-
-The memory map can be used as a read-only or read-write map. It is
-read-only by default as this provides total immunity to corruption.
-Using read-write mode offers much higher write performance, but adds the
-possibility for stray application writes thru pointers to silently
-corrupt the database.
-
-
-Features
-========
-
-- Key-value data model, keys are always sorted.
-
-- Fully ACID-compliant, through to MVCC and CoW.
-
-- Multiple key-value sub-databases within a single datafile.
-
-- Range lookups, including range query estimation.
-
-- Efficient support for short fixed length keys, including native
-  32/64-bit integers.
-
-- Ultra-efficient support for multimaps. Multi-values sorted, searchable
-  and iterable. Keys stored without duplication.
-
-- Data is memory-mapped and accessible directly/zero-copy. Traversal of
-  database records is extremely-fast.
-
-- Transactions for readers and writers, ones do not block others.
-
-- Writes are strongly serialized. No transaction conflicts nor
-  deadlocks.
-
-- Readers are non-blocking, notwithstanding snapshot isolation.
-
-- Nested write transactions.
-
-- Reads scale linearly across CPUs.
-
-- Continuous zero-overhead database compactification.
-
-- Automatic on-the-fly database size adjustment.
-
-- Customizable database page size.
-
-- Olog(N) cost of lookup, insert, update, and delete operations by
-  virtue of B+ tree characteristics.
-
-- Online hot backup.
-
-- Append operation for efficient bulk insertion of pre-sorted data.
-
-- No WAL nor any transaction journal. No crash recovery needed. No
-  maintenance is required.
-
-- No internal cache and/or memory management, all done by basic OS
-  services.
-
-
-Limitations
-===========
-
-- Page size: a power of 2, maximum 65536 bytes, default 4096 bytes.
-
-- Key size: minimum 0, maximum ≈¼ pagesize (1300 bytes for default 4K
-  pagesize, 21780 bytes for 64K pagesize).
-
-- Value size: minimum 0, maximum 2146435072 (0x7FF00000) bytes for maps,
-  ≈¼ pagesize for multimaps (1348 bytes default 4K pagesize, 21828 bytes
-  for 64K pagesize).
-
-- Write transaction size: up to 4194301 (0x3FFFFD) pages (16 GiB for
-  default 4K pagesize, 256 GiB for 64K pagesize).
-
-- Database size: up to 2147483648 pages (8 TiB for default 4K pagesize,
-  128 TiB for 64K pagesize).
-
-- Maximum sub-databases: 32765.
-
-
-Gotchas
-=======
-
-- There cannot be more than one writer at a time, i.e. no more than one
-  write transaction at a time.
-
-- libmdbx is based on B+ tree, so access to database pages is mostly
-  random. Thus SSDs provide a significant performance boost over
-  spinning disks for large databases.
-
-- libmdbx uses shadow paging instead of WAL. Thus syncing data to disk
-  might be a bottleneck for write intensive workload.
-
-- libmdbx uses copy-on-write for snapshot isolation during updates, but
-  read transactions prevents recycling an old retired/freed pages, since
-  it read ones. Thus altering of data during a parallel long-lived read
-  operation will increase the process work set, may exhaust entire free
-  database space, the database can grow quickly, and result in
-  performance degradation. Try to avoid long running read transactions.
-
-- libmdbx is extraordinarily fast and provides minimal overhead for data
-  access, so you should reconsider using brute force techniques and
-  double check your code. On the one hand, in the case of libmdbx, a
-  simple linear search may be more profitable than complex indexes. On
-  the other hand, if you make something suboptimally, you can notice
-  detrimentally only on sufficiently large data.
-
---
-Leonid Yuriev (1):
-  package/libmdbx: new package (library/database).
-
- DEVELOPERS                   |  3 +++
- package/Config.in            |  1 +
- package/libmdbx/Config.in    | 45 ++++++++++++++++++++++++++++++++++++
- package/libmdbx/libmdbx.hash |  5 ++++
- package/libmdbx/libmdbx.mk   | 33 ++++++++++++++++++++++++++
- 5 files changed, 87 insertions(+)
- create mode 100644 package/libmdbx/Config.in
- create mode 100644 package/libmdbx/libmdbx.hash
- create mode 100644 package/libmdbx/libmdbx.mk
-
--- 
-2.29.2

src/bits.md

@@ -1,34 +1,34 @@
-N |   MASK  | ENV       | TXN          | DB       | PUT       | DBI        | NODE    | PAGE     |
---|---------|-----------|--------------|----------|-----------|------------|---------|----------|
-0 |0000 0001|ALLOC_CACHE|TXN_FINISHED  |          |           |DBI_DIRTY   |F_BIGDATA|P_BRANCH
-1 |0000 0002|ALLOC_GC   |TXN_ERROR     |REVERSEKEY|F_SUBDATA  |DBI_STALE   |F_SUBDATA|P_LEAF
-2 |0000 0004|ALLOC_NEW  |TXN_DIRTY     |DUPSORT   |           |DBI_FRESH   |F_DUPDATA|P_OVERFLOW
-3 |0000 0008|ALLOC_SLOT |TXN_SPILLS    |INTEGERKEY|           |DBI_CREAT   |         |P_META
-4 |0000 0010|           |TXN_HAS_CHILD |DUPFIXED  |NOOVERWRITE|DBI_VALID   |         |P_BAD
-5 |0000 0020|           |              |INTEGERDUP|NODUPDATA  |DBI_USRVALID|         |P_LEAF2
-6 |0000 0040|           |              |REVERSEDUP|CURRENT    |DBI_DUPDATA |         |P_SUBP
-7 |0000 0080|           |              |          |ALLDUPS    |DBI_AUDITED |         |
-8 |0000 0100|           |              |          |           |            |         |
-9 |0000 0200|           |              |          |           |            |         |
-10|0000 0400|           |              |          |           |            |         |
-11|0000 0800|           |              |          |           |            |         |
-12|0000 1000|           |              |          |           |            |         |
-13|0000 2000|           |              |          |           |            |         |P_SPILLED
-14|0000 4000|NOSUBDIR   |              |          |           |            |         |P_LOOSE
-15|0000 8000|           |              |DB_VALID  |NOSPILL    |            |         |P_FROZEN
-16|0001 0000|SAFE_NOSYNC|TXN_NOSYNC    |          |RESERVE    |            |RESERVE  |
-17|0002 0000|RDONLY     |TXN_RDONLY    |          |APPEND     |            |APPEND   |
-18|0004 0000|NOMETASYNC |TXN_NOMETASYNC|CREATE    |APPENDDUP
-19|0008 0000|WRITEMAP   |<=            |          |MULTIPLE
-20|0010 0000|UTTERLY    |              |
-21|0020 0000|NOTLS      |<=            |
-22|0040 0000|EXCLUSIVE  |              |
-23|0080 0000|NORDAHEAD  |              |
-24|0100 0000|NOMEMINIT  |TXN_PREPARE   |
-25|0200 0000|COALESCE   |              |
-26|0400 0000|LIFORECLAIM|              |
-27|0800 0000|PAGEPERTURB|              |
-28|1000 0000|ENV_TXKEY  |TXN_TRY       |
-29|2000 0000|ENV_ACTIVE |              |
-30|4000 0000|ACCEDE     |SHRINK_ALLOWED|DB_ACCEDE
-31|8000 0000|FATAL_ERROR|              |
+N |   MASK  | ENV       | TXN          | DB       | PUT       | DBI        | NODE    | PAGE     | MRESIZE |
+--|---------|-----------|--------------|----------|-----------|------------|---------|----------|---------|
+0 |0000 0001|ALLOC_CACHE|TXN_FINISHED  |          |           |DBI_DIRTY   |F_BIGDATA|P_BRANCH  |         |
+1 |0000 0002|ALLOC_GC   |TXN_ERROR     |REVERSEKEY|F_SUBDATA  |DBI_STALE   |F_SUBDATA|P_LEAF    |         |
+2 |0000 0004|ALLOC_NEW  |TXN_DIRTY     |DUPSORT   |           |DBI_FRESH   |F_DUPDATA|P_OVERFLOW|         |
+3 |0000 0008|ALLOC_SLOT |TXN_SPILLS    |INTEGERKEY|           |DBI_CREAT   |         |P_META    |         |
+4 |0000 0010|           |TXN_HAS_CHILD |DUPFIXED  |NOOVERWRITE|DBI_VALID   |         |P_BAD     |         |
+5 |0000 0020|           |              |INTEGERDUP|NODUPDATA  |DBI_USRVALID|         |P_LEAF2   |         |
+6 |0000 0040|           |              |REVERSEDUP|CURRENT    |DBI_DUPDATA |         |P_SUBP    |         |
+7 |0000 0080|           |              |          |ALLDUPS    |DBI_AUDITED |         |          |         |
+8 |0000 0100| _MAY_MOVE |              |          |           |            |         |          | <=      |
+9 |0000 0200| _MAY_UNMAP|              |          |           |            |         |          | <=      |
+10|0000 0400|           |              |          |           |            |         |          |         |
+11|0000 0800|           |              |          |           |            |         |          |         |
+12|0000 1000|           |              |          |           |            |         |          |         |
+13|0000 2000|           |              |          |           |            |         |P_SPILLED |         |
+14|0000 4000|NOSUBDIR   |              |          |           |            |         |P_LOOSE   |         |
+15|0000 8000|           |              |DB_VALID  |NOSPILL    |            |         |P_FROZEN  |         |
+16|0001 0000|SAFE_NOSYNC|TXN_NOSYNC    |          |RESERVE    |            |RESERVE  |          |         |
+17|0002 0000|RDONLY     |TXN_RDONLY    |          |APPEND     |            |APPEND   |          | <=      |
+18|0004 0000|NOMETASYNC |TXN_NOMETASYNC|CREATE    |APPENDDUP  |            |         |          |         |
+19|0008 0000|WRITEMAP   |<=            |          |MULTIPLE   |            |         |          | <=      |
+20|0010 0000|UTTERLY    |              |          |           |            |         |          | <=      |
+21|0020 0000|NOTLS      |<=            |          |           |            |         |          |         |
+22|0040 0000|EXCLUSIVE  |              |          |           |            |         |          |         |
+23|0080 0000|NORDAHEAD  |              |          |           |            |         |          |         |
+24|0100 0000|NOMEMINIT  |TXN_PREPARE   |          |           |            |         |          |         |
+25|0200 0000|COALESCE   |              |          |           |            |         |          |         |
+26|0400 0000|LIFORECLAIM|              |          |           |            |         |          |         |
+27|0800 0000|PAGEPERTURB|              |          |           |            |         |          |         |
+28|1000 0000|ENV_TXKEY  |TXN_TRY       |          |           |            |         |          |         |
+29|2000 0000|ENV_ACTIVE |              |          |           |            |         |          |         |
+30|4000 0000|ACCEDE     |SHRINK_ALLOWED|DB_ACCEDE |           |            |         |          |         |
+31|8000 0000|FATAL_ERROR|              |          |           |            |         |          |         |

src/defs.h

@@ -103,14 +103,6 @@
 #   endif
 #endif /* __must_check_result */
 
-#ifndef __maybe_unused
-#   if defined(__GNUC__) || __has_attribute(__unused__)
-#       define __maybe_unused __attribute__((__unused__))
-#   else
-#       define __maybe_unused
-#   endif
-#endif /* __maybe_unused */
-
 #if !defined(__noop) && !defined(_MSC_VER)
 #   define __noop(...) do {} while(0)
 #endif /* __noop */
@@ -198,7 +190,7 @@
 #       elif defined(__GNUC__) || __has_attribute(__hot__)
 #           define __hot __attribute__((__hot__)) __optimize("O3")
 #       else
-#           define __hot  __optimize("O3")
+#           define __hot __optimize("O3")
 #       endif
 #   else
 #       define __hot
@@ -256,7 +248,7 @@
 #endif /* __anonymous_struct_extension__ */
 
 #ifndef __Wpedantic_format_voidptr
-    static __inline __maybe_unused const void* MDBX_PURE_FUNCTION
+    MDBX_MAYBE_UNUSED MDBX_PURE_FUNCTION static __inline  const void*
         __Wpedantic_format_voidptr(const void* ptr) {return ptr;}
 #   define __Wpedantic_format_voidptr(ARG) __Wpedantic_format_voidptr(ARG)
 #endif /* __Wpedantic_format_voidptr */
@@ -312,11 +304,6 @@
 #   define ARRAY_END(array) (&array[ARRAY_LENGTH(array)])
 #endif /* ARRAY_END */
 
-#ifndef STRINGIFY
-#   define STRINGIFY_HELPER(x) #x
-#   define STRINGIFY(x) STRINGIFY_HELPER(x)
-#endif /* STRINGIFY */
-
 #define CONCAT(a,b) a##b
 #define XCONCAT(a,b) CONCAT(a,b)
 
@@ -334,7 +321,7 @@
 
 #define MDBX_STRING_TETRAD(str) MDBX_TETRAD(str[0], str[1], str[2], str[3])
 
-#define FIXME "FIXME: " __FILE__ ", " STRINGIFY(__LINE__)
+#define FIXME "FIXME: " __FILE__ ", " MDBX_STRINGIFY(__LINE__)
 
 #ifndef STATIC_ASSERT_MSG
 #   if defined(static_assert)

src/internals.h

@@ -61,13 +61,26 @@
  * Studio 2015 Update 3). But you could remove this #error and try to continue
  * at your own risk. In such case please don't rise up an issues related ONLY to
  * old compilers.
+ *
+ * NOTE:
+ *   Unfortunately, there are several different builds of "Visual Studio" that
+ *   are called "Visual Studio 2015 Update 3".
+ *
+ *   The 190024234 is used here because it is minimal version of Visual Studio
+ *   that was used for build and testing libmdbx in recent years. Soon this
+ *   value will be increased to 19.0.24241.7, since build and testing using
+ *   "Visual Studio 2015" will be performed only at https://ci.appveyor.com.
+ *
+ *   Please ask Microsoft (but not us) for information about version differences
+ *   and how to and where you can obtain the latest "Visual Studio 2015" build
+ *   with all fixes.
  */
 #error                                                                         \
     "At least \"Microsoft C/C++ Compiler\" version 19.00.24234 (Visual Studio 2015 Update 3) is required."
 #endif
 #ifndef _CRT_SECURE_NO_WARNINGS
 #define _CRT_SECURE_NO_WARNINGS
-#endif
+#endif /* _CRT_SECURE_NO_WARNINGS */
 #if _MSC_VER > 1800
 #pragma warning(disable : 4464) /* relative include path contains '..' */
 #endif
@@ -264,9 +277,7 @@ static __always_inline memory_order mo_c11_load(enum MDBX_memory_order fence) {
 
 #ifndef __cplusplus
 
-static __inline void mdbx_jitter4testing(bool tiny);
-
-static __maybe_unused __always_inline void
+MDBX_MAYBE_UNUSED static __always_inline void
 mdbx_memory_fence(enum MDBX_memory_order order, bool write) {
 #ifdef MDBX_HAVE_C11ATOMICS
   atomic_thread_fence(write ? mo_c11_store(order) : mo_c11_load(order));
@@ -278,7 +289,7 @@ mdbx_memory_fence(enum MDBX_memory_order order, bool write) {
 #endif /* MDBX_HAVE_C11ATOMICS */
 }
 
-static __maybe_unused __always_inline uint32_t
+MDBX_MAYBE_UNUSED static __always_inline uint32_t
 atomic_store32(MDBX_atomic_uint32_t *p, const uint32_t value,
                enum MDBX_memory_order order) {
   STATIC_ASSERT(sizeof(MDBX_atomic_uint32_t) == 4);
@@ -294,7 +305,7 @@ atomic_store32(MDBX_atomic_uint32_t *p, const uint32_t value,
   return value;
 }
 
-static __maybe_unused __always_inline uint32_t
+MDBX_MAYBE_UNUSED static __always_inline uint32_t
 atomic_load32(const MDBX_atomic_uint32_t *p, enum MDBX_memory_order order) {
   STATIC_ASSERT(sizeof(MDBX_atomic_uint32_t) == 4);
 #ifdef MDBX_HAVE_C11ATOMICS
@@ -309,70 +320,6 @@ atomic_load32(const MDBX_atomic_uint32_t *p, enum MDBX_memory_order order) {
 #endif /* MDBX_HAVE_C11ATOMICS */
 }
 
-static __maybe_unused __always_inline uint64_t
-atomic_store64(MDBX_atomic_uint64_t *p, const uint64_t value,
-               enum MDBX_memory_order order) {
-  STATIC_ASSERT(sizeof(MDBX_atomic_uint64_t) == 8);
-#if MDBX_64BIT_ATOMIC
-#ifdef MDBX_HAVE_C11ATOMICS
-  assert(atomic_is_lock_free(MDBX_c11a_rw(uint64_t, p)));
-  atomic_store_explicit(MDBX_c11a_rw(uint64_t, p), value, mo_c11_store(order));
-#else  /* MDBX_HAVE_C11ATOMICS */
-  if (order != mo_Relaxed)
-    mdbx_compiler_barrier();
-  p->weak = value;
-  mdbx_memory_fence(order, true);
-#endif /* MDBX_HAVE_C11ATOMICS */
-#else  /* !MDBX_64BIT_ATOMIC */
-  mdbx_compiler_barrier();
-  atomic_store32(&p->low, (uint32_t)value, mo_Relaxed);
-  mdbx_jitter4testing(true);
-  atomic_store32(&p->high, (uint32_t)(value >> 32), order);
-  mdbx_jitter4testing(true);
-#endif /* !MDBX_64BIT_ATOMIC */
-  return value;
-}
-
-static __maybe_unused
-#if MDBX_64BIT_ATOMIC
-    __always_inline
-#endif /* MDBX_64BIT_ATOMIC */
-        uint64_t
-        atomic_load64(const MDBX_atomic_uint64_t *p,
-                      enum MDBX_memory_order order) {
-  STATIC_ASSERT(sizeof(MDBX_atomic_uint64_t) == 8);
-#if MDBX_64BIT_ATOMIC
-#ifdef MDBX_HAVE_C11ATOMICS
-  assert(atomic_is_lock_free(MDBX_c11a_ro(uint64_t, p)));
-  return atomic_load_explicit(MDBX_c11a_ro(uint64_t, p), mo_c11_load(order));
-#else  /* MDBX_HAVE_C11ATOMICS */
-  mdbx_memory_fence(order, false);
-  const uint64_t value = p->weak;
-  if (order != mo_Relaxed)
-    mdbx_compiler_barrier();
-  return value;
-#endif /* MDBX_HAVE_C11ATOMICS */
-#else  /* !MDBX_64BIT_ATOMIC */
-  mdbx_compiler_barrier();
-  uint64_t value = (uint64_t)atomic_load32(&p->high, order) << 32;
-  mdbx_jitter4testing(true);
-  value |= atomic_load32(&p->low, (order == mo_Relaxed) ? mo_Relaxed
-                                                        : mo_AcquireRelease);
-  mdbx_jitter4testing(true);
-  for (;;) {
-    mdbx_compiler_barrier();
-    uint64_t again = (uint64_t)atomic_load32(&p->high, order) << 32;
-    mdbx_jitter4testing(true);
-    again |= atomic_load32(&p->low, (order == mo_Relaxed) ? mo_Relaxed
-                                                          : mo_AcquireRelease);
-    mdbx_jitter4testing(true);
-    if (likely(value == again))
-      return value;
-    value = again;
-  }
-#endif /* !MDBX_64BIT_ATOMIC */
-}
-
 #endif /* !__cplusplus */
 
 /*----------------------------------------------------------------------------*/
@@ -384,7 +331,7 @@ static __maybe_unused
 #define MDBX_MAGIC UINT64_C(/* 56-bit prime */ 0x59659DBDEF4C11)
 
 /* FROZEN: The version number for a database's datafile format. */
-#define MDBX_DATA_VERSION 2
+#define MDBX_DATA_VERSION 3
 /* The version number for a database's lockfile format. */
 #define MDBX_LOCK_VERSION 4
 
@@ -437,7 +384,7 @@ typedef uint16_t indx_t;
 
 /*----------------------------------------------------------------------------*/
 /* Core structures for database and shared memory (i.e. format definition) */
-#pragma pack(push, 1)
+#pragma pack(push, 4)
 
 /* Information about a single database in the environment. */
 typedef struct MDBX_db {
@@ -488,8 +435,6 @@ typedef struct MDBX_meta {
   MDBX_db mm_dbs[CORE_DBS]; /* first is free space, 2nd is main db */
                             /* The size of pages used in this DB */
 #define mm_psize mm_dbs[FREE_DBI].md_xsize
-/* Any persistent environment flags, see mdbx_env */
-#define mm_flags mm_dbs[FREE_DBI].md_flags
   MDBX_canary mm_canary;
 
 #define MDBX_DATASIGN_NONE 0u
@@ -517,6 +462,8 @@ typedef struct MDBX_meta {
 
 } MDBX_meta;
 
+#pragma pack(1)
+
 /* Common header for all page types. The page type depends on mp_flags.
  *
  * P_BRANCH and P_LEAF pages have unsorted 'MDBX_node's at the end, with
@@ -787,7 +734,11 @@ typedef struct MDBX_lockinfo {
 
 #define MDBX_DATA_MAGIC                                                        \
   ((MDBX_MAGIC << 8) + MDBX_PNL_ASCENDING * 64 + MDBX_DATA_VERSION)
-#define MDBX_DATA_MAGIC_DEVEL ((MDBX_MAGIC << 8) + 255)
+
+#define MDBX_DATA_MAGIC_LEGACY_COMPAT                                          \
+  ((MDBX_MAGIC << 8) + MDBX_PNL_ASCENDING * 64 + 2)
+
+#define MDBX_DATA_MAGIC_LEGACY_DEVEL ((MDBX_MAGIC << 8) + 255)
 
 #define MDBX_LOCK_MAGIC ((MDBX_MAGIC << 8) + MDBX_LOCK_VERSION)
 
@@ -818,15 +769,13 @@ typedef struct MDBX_lockinfo {
 
 #if MDBX_WORDBITS >= 64
 #define MAX_MAPSIZE MAX_MAPSIZE64
-#define MDBX_READERS_LIMIT                                                     \
-  ((MAX_PAGESIZE - sizeof(MDBX_lockinfo)) / sizeof(MDBX_reader))
 #define MDBX_PGL_LIMIT ((size_t)MAX_PAGENO)
 #else
-#define MDBX_READERS_LIMIT 1024
 #define MAX_MAPSIZE MAX_MAPSIZE32
 #define MDBX_PGL_LIMIT (MAX_MAPSIZE32 / MIN_PAGESIZE)
 #endif /* MDBX_WORDBITS */
 
+#define MDBX_READERS_LIMIT 32767
 #define MDBX_RADIXSORT_THRESHOLD 333
 
 /*----------------------------------------------------------------------------*/
@@ -921,15 +870,7 @@ typedef struct MDBX_dbx {
  * Every operation requires a transaction handle. */
 struct MDBX_txn {
 #define MDBX_MT_SIGNATURE UINT32_C(0x93D53A31)
-  size_t mt_signature;
-  MDBX_txn *mt_parent; /* parent of a nested txn */
-  /* Nested txn under this txn, set together with flag MDBX_TXN_HAS_CHILD */
-  MDBX_txn *mt_child;
-  MDBX_geo mt_geo;
-  /* next unallocated page */
-#define mt_next_pgno mt_geo.next
-  /* corresponding to the current size of datafile */
-#define mt_end_pgno mt_geo.now
+  uint32_t mt_signature;
 
   /* Transaction Flags */
   /* mdbx_txn_begin() flags */
@@ -958,8 +899,17 @@ struct MDBX_txn {
      MDBX_SHRINK_ALLOWED)
 #error "Oops, some flags overlapped or wrong"
 #endif
+  uint32_t mt_flags;
+
+  MDBX_txn *mt_parent; /* parent of a nested txn */
+  /* Nested txn under this txn, set together with flag MDBX_TXN_HAS_CHILD */
+  MDBX_txn *mt_child;
+  MDBX_geo mt_geo;
+  /* next unallocated page */
+#define mt_next_pgno mt_geo.next
+  /* corresponding to the current size of datafile */
+#define mt_end_pgno mt_geo.now
 
-  unsigned mt_flags;
   /* The ID of this transaction. IDs are integers incrementing from 1.
    * Only committed write transactions increment the ID. If a transaction
    * aborts, the ID may be re-used by the next writer. */
@@ -1147,7 +1097,7 @@ struct MDBX_env {
   mdbx_thread_key_t me_txkey; /* thread-key for readers */
   char *me_pathname;          /* path to the DB files */
   void *me_pbuf;              /* scratch area for DUPSORT put() */
-  MDBX_txn *me_txn0;          /* prealloc'd write transaction */
+  MDBX_txn *me_txn0;          /* preallocated write transaction */
 
   MDBX_dbx *me_dbxs;    /* array of static DB info */
   uint16_t *me_dbflags; /* array of flags from MDBX_db.md_flags */
@@ -1252,6 +1202,15 @@ extern uint8_t mdbx_runtime_flags;
 extern uint8_t mdbx_loglevel;
 extern MDBX_debug_func *mdbx_debug_logger;
 
+MDBX_MAYBE_UNUSED static __inline void mdbx_jitter4testing(bool tiny) {
+#if MDBX_DEBUG
+  if (MDBX_DBG_JITTER & mdbx_runtime_flags)
+    mdbx_osal_jitter(tiny);
+#else
+  (void)tiny;
+#endif
+}
+
 MDBX_INTERNAL_FUNC void MDBX_PRINTF_ARGS(4, 5)
     mdbx_debug_log(int level, const char *function, int line, const char *fmt,
                    ...) MDBX_PRINTF_ARGS(4, 5);
@@ -1379,7 +1338,7 @@ void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *func,
 #define mdbx_flush_incoherent_cpu_writeback() mdbx_compiler_barrier()
 #endif /* MDBX_CPU_WRITEBACK_INCOHERENT */
 
-static __maybe_unused __inline void
+MDBX_MAYBE_UNUSED static __inline void
 mdbx_flush_incoherent_mmap(void *addr, size_t nbytes, const intptr_t pagesize) {
 #if MDBX_MMAP_INCOHERENT_FILE_WRITE
   char *const begin = (char *)(-pagesize & (intptr_t)addr);
@@ -1421,15 +1380,6 @@ MDBX_INTERNAL_FUNC void mdbx_rthc_global_init(void);
 MDBX_INTERNAL_FUNC void mdbx_rthc_global_dtor(void);
 MDBX_INTERNAL_FUNC void mdbx_rthc_thread_dtor(void *ptr);
 
-static __maybe_unused __inline void mdbx_jitter4testing(bool tiny) {
-#if MDBX_DEBUG
-  if (MDBX_DBG_JITTER & mdbx_runtime_flags)
-    mdbx_osal_jitter(tiny);
-#else
-  (void)tiny;
-#endif
-}
-
 #endif /* !__cplusplus */
 
 #define MDBX_IS_ERROR(rc)                                                      \
@@ -1564,45 +1514,46 @@ typedef struct MDBX_node {
  *                |  1, a > b
  *                \
  */
-#if 1
+#ifndef __e2k__
 /* LY: fast enough on most systems */
 #define CMP2INT(a, b) (((b) > (a)) ? -1 : (a) > (b))
 #else
+/* LY: more parallelable on VLIW Elbrus */
 #define CMP2INT(a, b) (((a) > (b)) - ((b) > (a)))
 #endif
 
 /* Do not spill pages to disk if txn is getting full, may fail instead */
 #define MDBX_NOSPILL 0x8000
 
-MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __inline pgno_t
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static __inline pgno_t
 pgno_add(pgno_t base, pgno_t augend) {
   assert(base <= MAX_PAGENO);
   return (augend < MAX_PAGENO - base) ? base + augend : MAX_PAGENO;
 }
 
-MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __inline pgno_t
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static __inline pgno_t
 pgno_sub(pgno_t base, pgno_t subtrahend) {
   assert(base >= MIN_PAGENO);
   return (subtrahend < base - MIN_PAGENO) ? base - subtrahend : MIN_PAGENO;
 }
 
-MDBX_NOTHROW_CONST_FUNCTION static __always_inline __maybe_unused bool
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static __always_inline bool
 is_powerof2(size_t x) {
   return (x & (x - 1)) == 0;
 }
 
-MDBX_NOTHROW_CONST_FUNCTION static __always_inline __maybe_unused size_t
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static __always_inline size_t
 floor_powerof2(size_t value, size_t granularity) {
   assert(is_powerof2(granularity));
   return value & ~(granularity - 1);
 }
 
-MDBX_NOTHROW_CONST_FUNCTION static __always_inline __maybe_unused size_t
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static __always_inline size_t
 ceil_powerof2(size_t value, size_t granularity) {
   return floor_powerof2(value + granularity - 1, granularity);
 }
 
-MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused unsigned
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static unsigned
 log2n_powerof2(size_t value) {
   assert(value > 0 && value < INT32_MAX && is_powerof2(value));
   assert((value & -(int32_t)value) == value);
@@ -1632,7 +1583,7 @@ log2n_powerof2(size_t value) {
 #define ENV_USABLE_FLAGS (ENV_CHANGEABLE_FLAGS | ENV_CHANGELESS_FLAGS)
 
 #if !defined(__cplusplus) || CONSTEXPR_ENUM_FLAGS_OPERATIONS
-static __maybe_unused void static_checks(void) {
+MDBX_MAYBE_UNUSED static void static_checks(void) {
   STATIC_ASSERT_MSG(INT16_MAX - CORE_DBS == MDBX_MAX_DBI,
                     "Oops, MDBX_MAX_DBI or CORE_DBS?");
   STATIC_ASSERT_MSG((unsigned)(MDBX_DB_ACCEDE | MDBX_CREATE) ==
@@ -1647,3 +1598,17 @@ static __maybe_unused void static_checks(void) {
 #ifdef __cplusplus
 }
 #endif
+
+#define MDBX_ASAN_POISON_MEMORY_REGION(addr, size)                             \
+  do {                                                                         \
+    mdbx_trace("POISON_MEMORY_REGION(%p, %zu) at %u", (void *)(addr),          \
+               (size_t)(size), __LINE__);                                      \
+    ASAN_POISON_MEMORY_REGION(addr, size);                                     \
+  } while (0)
+
+#define MDBX_ASAN_UNPOISON_MEMORY_REGION(addr, size)                           \
+  do {                                                                         \
+    mdbx_trace("UNPOISON_MEMORY_REGION(%p, %zu) at %u", (void *)(addr),        \
+               (size_t)(size), __LINE__);                                      \
+    ASAN_UNPOISON_MEMORY_REGION(addr, size);                                   \
+  } while (0)

src/lck-posix.c

@@ -29,33 +29,27 @@ uint32_t mdbx_linux_kernel_version;
 bool mdbx_RunningOnWSL1;
 #endif /* xMDBX_ALLOY */
 
-static __cold uint8_t probe_for_WSL(const char *tag) {
+__cold static uint8_t probe_for_WSL(const char *tag) {
   const char *const WSL = strstr(tag, "WSL");
   if (WSL && WSL[3] >= '2' && WSL[3] <= '9')
     return WSL[3] - '0';
   const char *const wsl = strstr(tag, "wsl");
   if (wsl && wsl[3] >= '2' && wsl[3] <= '9')
     return wsl[3] - '0';
-  return (WSL || wsl || strcasestr(tag, "Microsoft")) ? 1 : 0;
+  if (WSL || wsl || strcasestr(tag, "Microsoft"))
+    /* Expecting no new kernel within WSL1, either it will explicitly
+     * marked by an appropriate WSL-version hint. */
+    return (mdbx_linux_kernel_version < /* 4.19.x */ 0x04130000) ? 1 : 2;
+  return 0;
 }
 
 #endif /* Linux */
 
-static __cold __attribute__((__constructor__)) void
+__cold static __attribute__((__constructor__)) void
 mdbx_global_constructor(void) {
 #if defined(__linux__) || defined(__gnu_linux__)
   struct utsname buffer;
   if (uname(&buffer) == 0) {
-    /* "Official" way of detecting WSL1 but not WSL2
-     * https://github.com/Microsoft/WSL/issues/423#issuecomment-221627364
-     *
-     * WARNING: False negative detection of WSL1 will result in DATA LOSS!
-     * So, the REQUIREMENTS for this code:
-     *  1. MUST detect WSL1 without false-negatives.
-     *  2. DESIRABLE detect WSL2 but without the risk of violating the first. */
-    mdbx_RunningOnWSL1 = probe_for_WSL(buffer.version) == 1 ||
-                         probe_for_WSL(buffer.sysname) == 1 ||
-                         probe_for_WSL(buffer.release) == 1;
     int i = 0;
     char *p = buffer.release;
     while (*p && i < 4) {
@@ -71,13 +65,23 @@ mdbx_global_constructor(void) {
         ++p;
       }
     }
+    /* "Official" way of detecting WSL1 but not WSL2
+     * https://github.com/Microsoft/WSL/issues/423#issuecomment-221627364
+     *
+     * WARNING: False negative detection of WSL1 will result in DATA LOSS!
+     * So, the REQUIREMENTS for this code:
+     *  1. MUST detect WSL1 without false-negatives.
+     *  2. DESIRABLE detect WSL2 but without the risk of violating the first. */
+    mdbx_RunningOnWSL1 = probe_for_WSL(buffer.version) == 1 ||
+                         probe_for_WSL(buffer.sysname) == 1 ||
+                         probe_for_WSL(buffer.release) == 1;
   }
 #endif /* Linux */
 
   mdbx_rthc_global_init();
 }
 
-static __cold __attribute__((__destructor__)) void
+__cold static __attribute__((__destructor__)) void
 mdbx_global_destructor(void) {
   mdbx_rthc_global_dtor();
 }
@@ -141,7 +145,7 @@ mdbx_global_destructor(void) {
 
 #if MDBX_USE_OFDLOCKS
 static int op_setlk, op_setlkw, op_getlk;
-static void __cold choice_fcntl() {
+__cold static void choice_fcntl() {
   assert(!op_setlk && !op_setlkw && !op_getlk);
   if ((mdbx_runtime_flags & MDBX_DBG_LEGACY_MULTIOPEN) == 0
 #if defined(__linux__) || defined(__gnu_linux__)
@@ -194,6 +198,22 @@ static int lck_op(mdbx_filehandle_t fd, int cmd, int lck, off_t offset,
       return MDBX_SUCCESS;
     }
     rc = errno;
+#if MDBX_USE_OFDLOCKS
+    if (rc == EINVAL &&
+        (cmd == F_OFD_SETLK || cmd == F_OFD_SETLKW || cmd == F_OFD_GETLK)) {
+      /* fallback to non-OFD locks */
+      if (cmd == F_OFD_SETLK)
+        cmd = F_SETLK;
+      else if (cmd == F_OFD_SETLKW)
+        cmd = F_SETLKW;
+      else
+        cmd = F_GETLK;
+      op_setlk = F_SETLK;
+      op_setlkw = F_SETLKW;
+      op_getlk = F_GETLK;
+      continue;
+    }
+#endif /* MDBX_USE_OFDLOCKS */
     if (rc != EINTR || cmd == op_setlkw) {
       mdbx_assert(nullptr, MDBX_IS_ERROR(rc));
       return rc;
@@ -314,7 +334,7 @@ static int check_fstat(MDBX_env *env) {
   return rc;
 }
 
-MDBX_INTERNAL_FUNC int __cold mdbx_lck_seize(MDBX_env *env) {
+__cold MDBX_INTERNAL_FUNC int mdbx_lck_seize(MDBX_env *env) {
   assert(env->me_lazy_fd != INVALID_HANDLE_VALUE);
   if (unlikely(mdbx_getpid() != env->me_pid))
     return MDBX_PANIC;
@@ -467,7 +487,7 @@ MDBX_INTERNAL_FUNC int mdbx_lck_downgrade(MDBX_env *env) {
   return rc;
 }
 
-MDBX_INTERNAL_FUNC int __cold mdbx_lck_destroy(MDBX_env *env,
+__cold MDBX_INTERNAL_FUNC int mdbx_lck_destroy(MDBX_env *env,
                                                MDBX_env *inprocess_neighbor) {
   if (unlikely(mdbx_getpid() != env->me_pid))
     return MDBX_PANIC;
@@ -554,7 +574,7 @@ MDBX_INTERNAL_FUNC int __cold mdbx_lck_destroy(MDBX_env *env,
 
 /*---------------------------------------------------------------------------*/
 
-MDBX_INTERNAL_FUNC int __cold mdbx_lck_init(MDBX_env *env,
+__cold MDBX_INTERNAL_FUNC int mdbx_lck_init(MDBX_env *env,
                                             MDBX_env *inprocess_neighbor,
                                             int global_uniqueness_flag) {
 #if MDBX_LOCKING == MDBX_LOCKING_SYSV
@@ -701,7 +721,7 @@ bailout:
 #endif /* MDBX_LOCKING > 0 */
 }
 
-static int __cold mdbx_ipclock_failed(MDBX_env *env, mdbx_ipclock_t *ipc,
+__cold static int mdbx_ipclock_failed(MDBX_env *env, mdbx_ipclock_t *ipc,
                                       const int err) {
   int rc = err;
 #if MDBX_LOCKING == MDBX_LOCKING_POSIX2008 || MDBX_LOCKING == MDBX_LOCKING_SYSV

src/lck-windows.c

@@ -260,6 +260,7 @@ static int suspend_and_append(mdbx_handle_array_t **array,
 
 MDBX_INTERNAL_FUNC int
 mdbx_suspend_threads_before_remap(MDBX_env *env, mdbx_handle_array_t **array) {
+  mdbx_assert(env, (env->me_flags & MDBX_NOTLS) == 0);
   const uintptr_t CurrentTid = GetCurrentThreadId();
   int rc;
   if (env->me_lck_mmap.lck) {
@@ -277,12 +278,6 @@ mdbx_suspend_threads_before_remap(MDBX_env *env, mdbx_handle_array_t **array) {
       if (reader->mr_tid.weak == CurrentTid ||
           reader->mr_tid.weak == WriteTxnOwner)
         goto skip_lck;
-      if (env->me_flags & MDBX_NOTLS) {
-        /* Skip duplicates in no-tls mode */
-        for (const MDBX_reader *scan = reader; --scan >= begin;)
-          if (scan->mr_tid.weak == reader->mr_tid.weak)
-            goto skip_lck;
-      }
 
       rc = suspend_and_append(array, (mdbx_tid_t)reader->mr_tid.weak);
       if (rc != MDBX_SUCCESS) {

src/man1/mdbx_stat.1

@@ -12,6 +12,8 @@ mdbx_stat \- MDBX environment status tool
 [\c
 .BR \-q ]
 [\c
+.BR \-p ]
+[\c
 .BR \-e ]
 [\c
 .BR \-f [ f [ f ]]]
@@ -35,13 +37,18 @@ Write the library version number to the standard output, and exit.
 .BR \-q
 Be quiet.
 .TP
+.BR \-p
+Display overall statistics of page operations of all (running, completed
+and aborted) transactions in the current multi-process session (since the
+first process opened the database after everyone had previously closed it).
+.TP
 .BR \-e
 Display information about the database environment.
 .TP
 .BR \-f
-Display information about the environment freelist.
-If \fB\-ff\fP is given, summarize each freelist entry.
-If \fB\-fff\fP is given, display the full list of page IDs in the freelist.
+Display information about the environment GC.
+If \fB\-ff\fP is given, summarize each GC/freelist entry.
+If \fB\-fff\fP is given, display the full list of page IDs in the GC/freelist.
 .TP
 .BR \-r
 Display information about the environment reader table.

src/mdbx.c++

@@ -5,9 +5,9 @@
 // Non-inline part of the libmdbx C++ API (preliminary)
 //
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
 #define _CRT_SECURE_NO_WARNINGS
-#endif
+#endif /* _CRT_SECURE_NO_WARNINGS */
 
 #include "../mdbx.h++"
 
@@ -124,7 +124,7 @@ public:
 
 //------------------------------------------------------------------------------
 
-__cold std::string format_va(const char *fmt, va_list ap) {
+__cold  std::string format_va(const char *fmt, va_list ap) {
   va_list ones;
   va_copy(ones, ap);
 #ifdef _MSC_VER
@@ -145,7 +145,7 @@ __cold std::string format_va(const char *fmt, va_list ap) {
   return result;
 }
 
-__cold std::string format(const char *fmt, ...) {
+__cold  std::string format(const char *fmt, ...) {
   va_list ap;
   va_start(ap, fmt);
   std::string result = format_va(fmt, ap);
@@ -166,15 +166,15 @@ public:
   virtual ~bug() noexcept;
 };
 
-__cold bug::bug(const trouble_location &location) noexcept
+__cold  bug::bug(const trouble_location &location) noexcept
     : std::runtime_error(format("mdbx.bug: %s.%s at %s:%u", location.function(),
                                 location.condition(), location.filename(),
                                 location.line())),
       location_(location) {}
 
-__cold bug::~bug() noexcept {}
+__cold  bug::~bug() noexcept {}
 
-[[noreturn]] __cold void raise_bug(const trouble_location &what_and_where) {
+[[noreturn]] __cold  void raise_bug(const trouble_location &what_and_where) {
   throw bug(what_and_where);
 }
 
@@ -188,7 +188,7 @@ __cold bug::~bug() noexcept {}
 #define ENSURE(condition)                                                      \
   do                                                                           \
     if (MDBX_UNLIKELY(!(condition)))                                           \
-      RAISE_BUG(__LINE__, #condition, __func__, __FILE__);                     \
+      MDBX_CXX20_UNLIKELY RAISE_BUG(__LINE__, #condition, __func__, __FILE__); \
   while (0)
 
 #define NOT_IMPLEMENTED()                                                      \
@@ -204,7 +204,8 @@ template <typename PATH> struct path_to_pchar {
   operator const char *() const { return str.c_str(); }
 };
 
-template <typename PATH> PATH pchar_to_path(const char *c_str) {
+template <typename PATH>
+MDBX_MAYBE_UNUSED PATH pchar_to_path(const char *c_str) {
   return PATH(c_str);
 }
 
@@ -241,7 +242,8 @@ template <> struct path_to_pchar<std::wstring> {
   operator const char *() const { return str.c_str(); }
 };
 
-template <> std::wstring pchar_to_path<std::wstring>(const char *c_str) {
+template <>
+MDBX_MAYBE_UNUSED std::wstring pchar_to_path<std::wstring>(const char *c_str) {
   std::wstring wstr;
   if (c_str && *c_str) {
     const int chars = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, c_str,
@@ -266,16 +268,22 @@ namespace mdbx {
 
 [[noreturn]] __cold void throw_max_length_exceeded() {
   throw std::length_error(
-      "mdbx:: exceeded the maximal length of data/slice/buffer");
+      "mdbx:: Exceeded the maximal length of data/slice/buffer.");
 }
 
 [[noreturn]] __cold void throw_too_small_target_buffer() {
-  throw std::length_error("mdbx:: the target buffer is too small");
+  throw std::length_error("mdbx:: The target buffer is too small.");
 }
 
 [[noreturn]] __cold void throw_out_range() {
-  throw std::out_of_range("mdbx:: slice or buffer method was called with "
-                          "an argument that exceeds the length");
+  throw std::out_of_range("mdbx:: Slice or buffer method was called with "
+                          "an argument that exceeds the length.");
+}
+
+[[noreturn]] __cold void throw_allocators_mismatch() {
+  throw std::logic_error(
+      "mdbx:: An allocators mismatch, so an object could not be transferred "
+      "into an incompatible memory allocation scheme.");
 }
 
 __cold exception::exception(const ::mdbx::error &error) noexcept
@@ -336,7 +344,7 @@ __cold const char *error::what() const noexcept {
   switch (code()) {
 #define ERROR_CASE(CODE)                                                       \
   case CODE:                                                                   \
-    return STRINGIFY(CODE)
+    return MDBX_STRINGIFY(CODE)
     ERROR_CASE(MDBX_ENODATA);
     ERROR_CASE(MDBX_EINVAL);
     ERROR_CASE(MDBX_EACCESS);
@@ -472,15 +480,15 @@ bool slice::is_printable(bool disable_utf8) const noexcept {
       F0, F1, F1, F1, F4, P_, P_, P_, P_, P_, P_, P_, P_, P_, P_, P_  // f0
   };
 
-  if (length() < 1)
-    return false;
+  if (MDBX_UNLIKELY(length() < 1))
+    MDBX_CXX20_UNLIKELY return false;
 
   auto src = byte_ptr();
   const auto end = src + length();
   if (MDBX_UNLIKELY(disable_utf8)) {
     do
       if (MDBX_UNLIKELY((P_ & map[*src]) == 0))
-        return false;
+        MDBX_CXX20_UNLIKELY return false;
     while (++src < end);
     return true;
   }
@@ -491,35 +499,35 @@ bool slice::is_printable(bool disable_utf8) const noexcept {
     const auto second_to = range_to[bits & second_range_mask];
     switch (bits >> LS) {
     default:
-      return false;
+      MDBX_CXX20_UNLIKELY return false;
     case 1:
       src += 1;
       continue;
     case 2:
-      if (unlikely(src + 1 >= end))
-        return false;
-      if (unlikely(src[1] < second_from || src[1] > second_to))
-        return false;
+      if (MDBX_UNLIKELY(src + 1 >= end))
+        MDBX_CXX20_UNLIKELY return false;
+      if (MDBX_UNLIKELY(src[1] < second_from || src[1] > second_to))
+        MDBX_CXX20_UNLIKELY return false;
       src += 2;
       continue;
     case 3:
-      if (unlikely(src + 3 >= end))
-        return false;
-      if (unlikely(src[1] < second_from || src[1] > second_to))
-        return false;
-      if (unlikely(src[2] < 0x80 || src[2] > 0xBF))
-        return false;
+      if (MDBX_UNLIKELY(src + 3 >= end))
+        MDBX_CXX20_UNLIKELY return false;
+      if (MDBX_UNLIKELY(src[1] < second_from || src[1] > second_to))
+        MDBX_CXX20_UNLIKELY return false;
+      if (MDBX_UNLIKELY(src[2] < 0x80 || src[2] > 0xBF))
+        MDBX_CXX20_UNLIKELY return false;
       src += 3;
       continue;
     case 4:
-      if (unlikely(src + 4 >= end))
-        return false;
-      if (unlikely(src[1] < second_from || src[1] > second_to))
-        return false;
-      if (unlikely(src[2] < 0x80 || src[2] > 0xBF))
-        return false;
-      if (unlikely(src[3] < 0x80 || src[3] > 0xBF))
-        return false;
+      if (MDBX_UNLIKELY(src + 4 >= end))
+        MDBX_CXX20_UNLIKELY return false;
+      if (MDBX_UNLIKELY(src[1] < second_from || src[1] > second_to))
+        MDBX_CXX20_UNLIKELY return false;
+      if (MDBX_UNLIKELY(src[2] < 0x80 || src[2] > 0xBF))
+        MDBX_CXX20_UNLIKELY return false;
+      if (MDBX_UNLIKELY(src[3] < 0x80 || src[3] > 0xBF))
+        MDBX_CXX20_UNLIKELY return false;
       src += 4;
       continue;
     }
@@ -530,15 +538,14 @@ bool slice::is_printable(bool disable_utf8) const noexcept {
 
 //------------------------------------------------------------------------------
 
-char *slice::to_hex(char *__restrict dest, size_t dest_size, bool uppercase,
-                    unsigned wrap_width) const {
-  if (MDBX_UNLIKELY(to_hex_bytes(wrap_width) > dest_size))
-    throw_too_small_target_buffer();
+char *to_hex::write_bytes(char *__restrict dest, size_t dest_size) const {
+  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
+    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();
 
-  auto src = byte_ptr();
+  auto src = source.byte_ptr();
   const char alphabase = (uppercase ? 'A' : 'a') - 10;
   auto line = dest;
-  for (const auto end = src + length(); src != end; ++src) {
+  for (const auto end = source.end_byte_ptr(); src != end; ++src) {
     const int8_t hi = *src >> 4;
     const int8_t lo = *src & 15;
     dest[0] = char(alphabase + hi + (((hi - 10) >> 7) & -7));
@@ -552,16 +559,15 @@ char *slice::to_hex(char *__restrict dest, size_t dest_size, bool uppercase,
   return dest;
 }
 
-byte *slice::from_hex(byte *__restrict dest, size_t dest_size,
-                      bool ignore_spaces) const {
-  if (MDBX_UNLIKELY(length() % 2 && !ignore_spaces))
-    throw std::domain_error(
+char *from_hex::write_bytes(char *__restrict dest, size_t dest_size) const {
+  if (MDBX_UNLIKELY(source.length() % 2 && !ignore_spaces))
+    MDBX_CXX20_UNLIKELY throw std::domain_error(
         "mdbx::from_hex:: odd length of hexadecimal string");
-  if (MDBX_UNLIKELY(from_hex_bytes() > dest_size))
-    throw_too_small_target_buffer();
+  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
+    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();
 
-  auto src = byte_ptr();
-  for (auto left = length(); left > 0;) {
+  auto src = source.byte_ptr();
+  for (auto left = source.length(); left > 0;) {
     if (MDBX_UNLIKELY(*src <= ' ') &&
         MDBX_LIKELY(ignore_spaces && isspace(*src))) {
       ++src;
@@ -570,7 +576,8 @@ byte *slice::from_hex(byte *__restrict dest, size_t dest_size,
     }
 
     if (MDBX_UNLIKELY(left < 1 || !isxdigit(src[0]) || !isxdigit(src[1])))
-      throw std::domain_error("mdbx::from_hex:: invalid hexadecimal string");
+      MDBX_CXX20_UNLIKELY throw std::domain_error(
+          "mdbx::from_hex:: invalid hexadecimal string");
 
     int8_t hi = src[0];
     hi = (hi | 0x20) - 'a';
@@ -587,13 +594,13 @@ byte *slice::from_hex(byte *__restrict dest, size_t dest_size,
   return dest;
 }
 
-bool slice::is_hex(bool ignore_spaces) const noexcept {
-  if (MDBX_UNLIKELY(length() % 2 && !ignore_spaces))
-    return false;
+bool from_hex::is_erroneous() const noexcept {
+  if (MDBX_UNLIKELY(source.length() % 2 && !ignore_spaces))
+    MDBX_CXX20_UNLIKELY return true;
 
   bool got = false;
-  auto src = byte_ptr();
-  for (auto left = length(); left > 0;) {
+  auto src = source.byte_ptr();
+  for (auto left = source.length(); left > 0;) {
     if (MDBX_UNLIKELY(*src <= ' ') &&
         MDBX_LIKELY(ignore_spaces && isspace(*src))) {
       ++src;
@@ -602,13 +609,13 @@ bool slice::is_hex(bool ignore_spaces) const noexcept {
     }
 
     if (MDBX_UNLIKELY(left < 1 || !isxdigit(src[0]) || !isxdigit(src[1])))
-      return false;
+      MDBX_CXX20_UNLIKELY return true;
 
     got = true;
     src += 2;
     left -= 2;
   }
-  return got;
+  return !got;
 }
 
 //------------------------------------------------------------------------------
@@ -656,13 +663,12 @@ static inline char b58_8to11(uint64_t &v) noexcept {
   return b58_alphabet[i];
 }
 
-char *slice::to_base58(char *__restrict dest, size_t dest_size,
-                       unsigned wrap_width) const {
-  if (MDBX_UNLIKELY(to_base58_bytes(wrap_width) > dest_size))
-    throw_too_small_target_buffer();
+char *to_base58::write_bytes(char *__restrict dest, size_t dest_size) const {
+  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
+    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();
 
-  auto src = byte_ptr();
-  size_t left = length();
+  auto src = source.byte_ptr();
+  size_t left = source.length();
   auto line = dest;
   while (MDBX_LIKELY(left > 7)) {
     left -= 8;
@@ -739,13 +745,12 @@ static inline signed char b58_11to8(uint64_t &v, const byte c) noexcept {
   return m;
 }
 
-byte *slice::from_base58(byte *__restrict dest, size_t dest_size,
-                         bool ignore_spaces) const {
-  if (MDBX_UNLIKELY(from_base58_bytes() > dest_size))
-    throw_too_small_target_buffer();
+char *from_base58::write_bytes(char *__restrict dest, size_t dest_size) const {
+  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
+    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();
 
-  auto src = byte_ptr();
-  for (auto left = length(); left > 0;) {
+  auto src = source.byte_ptr();
+  for (auto left = source.length(); left > 0;) {
     if (MDBX_UNLIKELY(isspace(*src)) && ignore_spaces) {
       ++src;
       --left;
@@ -760,7 +765,7 @@ byte *slice::from_base58(byte *__restrict dest, size_t dest_size,
                          b58_11to8(v, src[6]) | b58_11to8(v, src[7]) |
                          b58_11to8(v, src[8]) | b58_11to8(v, src[9]) |
                          b58_11to8(v, src[10])) < 0))
-        goto bailout;
+        MDBX_CXX20_UNLIKELY goto bailout;
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
       v = bswap64(v);
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
@@ -775,14 +780,14 @@ byte *slice::from_base58(byte *__restrict dest, size_t dest_size,
     }
 
     constexpr unsigned invalid_length_mask = 1 << 1 | 1 << 4 | 1 << 8;
-    if (invalid_length_mask & (1 << left))
-      goto bailout;
+    if (MDBX_UNLIKELY(invalid_length_mask & (1 << left)))
+      MDBX_CXX20_UNLIKELY goto bailout;
 
     uint64_t v = 1;
     unsigned parrots = 0;
     do {
       if (MDBX_UNLIKELY(b58_11to8(v, *src++) < 0))
-        goto bailout;
+        MDBX_CXX20_UNLIKELY goto bailout;
       parrots += 32;
     } while (--left);
 
@@ -799,10 +804,10 @@ bailout:
   throw std::domain_error("mdbx::from_base58:: invalid base58 string");
 }
 
-bool slice::is_base58(bool ignore_spaces) const noexcept {
+bool from_base58::is_erroneous() const noexcept {
   bool got = false;
-  auto src = byte_ptr();
-  for (auto left = length(); left > 0;) {
+  auto src = source.byte_ptr();
+  for (auto left = source.length(); left > 0;) {
     if (MDBX_UNLIKELY(*src <= ' ') &&
         MDBX_LIKELY(ignore_spaces && isspace(*src))) {
       ++src;
@@ -815,7 +820,7 @@ bool slice::is_base58(bool ignore_spaces) const noexcept {
                          b58_map[src[3]] | b58_map[src[4]] | b58_map[src[5]] |
                          b58_map[src[6]] | b58_map[src[7]] | b58_map[src[8]] |
                          b58_map[src[9]] | b58_map[src[10]]) < 0))
-        return false;
+        MDBX_CXX20_UNLIKELY return true;
       src += 11;
       left -= 11;
       got = true;
@@ -828,12 +833,12 @@ bool slice::is_base58(bool ignore_spaces) const noexcept {
 
     do
       if (MDBX_UNLIKELY(b58_map[*src++] < 0))
-        return false;
+        MDBX_CXX20_UNLIKELY return true;
     while (--left);
     got = true;
     break;
   }
-  return got;
+  return !got;
 }
 
 //------------------------------------------------------------------------------
@@ -852,13 +857,12 @@ static inline void b64_3to4(const byte x, const byte y, const byte z,
   dest[3] = alphabet[z & 0x3f];
 }
 
-char *slice::to_base64(char *__restrict dest, size_t dest_size,
-                       unsigned wrap_width) const {
-  if (MDBX_UNLIKELY(to_base64_bytes(wrap_width) > dest_size))
-    throw_too_small_target_buffer();
+char *to_base64::write_bytes(char *__restrict dest, size_t dest_size) const {
+  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
+    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();
 
-  auto src = byte_ptr();
-  size_t left = length();
+  auto src = source.byte_ptr();
+  size_t left = source.length();
   auto line = dest;
   while (true) {
     switch (left) {
@@ -908,22 +912,22 @@ static const signed char b64_map[256] = {
 
 static inline signed char b64_4to3(signed char a, signed char b, signed char c,
                                    signed char d,
-                                   byte *__restrict dest) noexcept {
+                                   char *__restrict dest) noexcept {
   dest[0] = byte((a << 2) + ((b & 0x30) >> 4));
   dest[1] = byte(((b & 0xf) << 4) + ((c & 0x3c) >> 2));
   dest[2] = byte(((c & 0x3) << 6) + d);
   return a | b | c | d;
 }
 
-byte *slice::from_base64(byte *__restrict dest, size_t dest_size,
-                         bool ignore_spaces) const {
-  if (MDBX_UNLIKELY(length() % 4 && !ignore_spaces))
-    throw std::domain_error("mdbx::from_base64:: odd length of base64 string");
-  if (MDBX_UNLIKELY(from_base64_bytes() > dest_size))
-    throw_too_small_target_buffer();
+char *from_base64::write_bytes(char *__restrict dest, size_t dest_size) const {
+  if (MDBX_UNLIKELY(source.length() % 4 && !ignore_spaces))
+    MDBX_CXX20_UNLIKELY throw std::domain_error(
+        "mdbx::from_base64:: odd length of base64 string");
+  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
+    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();
 
-  auto src = byte_ptr();
-  for (auto left = length(); left > 0;) {
+  auto src = source.byte_ptr();
+  for (auto left = source.length(); left > 0;) {
     if (MDBX_UNLIKELY(*src <= ' ') &&
         MDBX_LIKELY(ignore_spaces && isspace(*src))) {
       ++src;
@@ -931,10 +935,11 @@ byte *slice::from_base64(byte *__restrict dest, size_t dest_size,
       continue;
     }
 
-    if (MDBX_UNLIKELY(left < 3)) {
-    bailout:
-      throw std::domain_error("mdbx::from_base64:: invalid base64 string");
-    }
+    if (MDBX_UNLIKELY(left < 3))
+      MDBX_CXX20_UNLIKELY {
+      bailout:
+        throw std::domain_error("mdbx::from_base64:: invalid base64 string");
+      }
     const signed char a = b64_map[src[0]], b = b64_map[src[1]],
                       c = b64_map[src[2]], d = b64_map[src[3]];
     if (MDBX_UNLIKELY(b64_4to3(a, b, c, d, dest) < 0)) {
@@ -944,7 +949,7 @@ byte *slice::from_base64(byte *__restrict dest, size_t dest_size,
         if (c == d)
           return dest + 1;
       }
-      goto bailout;
+      MDBX_CXX20_UNLIKELY goto bailout;
     }
     src += 4;
     left -= 4;
@@ -952,13 +957,13 @@ byte *slice::from_base64(byte *__restrict dest, size_t dest_size,
   return dest;
 }
 
-bool slice::is_base64(bool ignore_spaces) const noexcept {
-  if (MDBX_UNLIKELY(length() % 4 && !ignore_spaces))
-    return false;
+bool from_base64::is_erroneous() const noexcept {
+  if (MDBX_UNLIKELY(source.length() % 4 && !ignore_spaces))
+    MDBX_CXX20_UNLIKELY return true;
 
   bool got = false;
-  auto src = byte_ptr();
-  for (auto left = length(); left > 0;) {
+  auto src = source.byte_ptr();
+  for (auto left = source.length(); left > 0;) {
     if (MDBX_UNLIKELY(*src <= ' ') &&
         MDBX_LIKELY(ignore_spaces && isspace(*src))) {
       ++src;
@@ -967,26 +972,28 @@ bool slice::is_base64(bool ignore_spaces) const noexcept {
     }
 
     if (MDBX_UNLIKELY(left < 3))
-      return false;
+      MDBX_CXX20_UNLIKELY return false;
     const signed char a = b64_map[src[0]], b = b64_map[src[1]],
                       c = b64_map[src[2]], d = b64_map[src[3]];
-    if (MDBX_UNLIKELY((a | b | c | d) < 0)) {
-      if (left == 4 && (a | b) >= 0 && d == EQ && (c >= 0 || c == d))
+    if (MDBX_UNLIKELY((a | b | c | d) < 0))
+      MDBX_CXX20_UNLIKELY {
+        if (left == 4 && (a | b) >= 0 && d == EQ && (c >= 0 || c == d))
+          return false;
         return true;
-      return false;
-    }
+      }
     got = true;
     src += 4;
     left -= 4;
   }
-  return got;
+  return !got;
 }
 
 //------------------------------------------------------------------------------
 
 template class LIBMDBX_API_TYPE buffer<legacy_allocator>;
 
-#if defined(__cpp_lib_memory_resource) && __cpp_lib_memory_resource >= 201603L
+#if defined(__cpp_lib_memory_resource) &&                                      \
+    __cpp_lib_memory_resource >= 201603L && _GLIBCXX_USE_CXX11_ABI
 template class LIBMDBX_API_TYPE buffer<polymorphic_allocator>;
 #endif /* __cpp_lib_memory_resource >= 201603L */
 
@@ -1183,9 +1190,9 @@ static inline MDBX_env *create_env() {
 }
 
 env_managed::~env_managed() noexcept {
-  if (handle_)
-    error::success_or_panic(::mdbx_env_close(handle_), "mdbx::~env()",
-                            "mdbx_env_close");
+  if (MDBX_UNLIKELY(handle_))
+    MDBX_CXX20_UNLIKELY error::success_or_panic(
+        ::mdbx_env_close(handle_), "mdbx::~env()", "mdbx_env_close");
 }
 
 void env_managed::close(bool dont_sync) {
@@ -1193,12 +1200,12 @@ void env_managed::close(bool dont_sync) {
       static_cast<MDBX_error_t>(::mdbx_env_close_ex(handle_, dont_sync));
   switch (rc.code()) {
   case MDBX_EBADSIGN:
-    handle_ = nullptr;
+    MDBX_CXX20_UNLIKELY handle_ = nullptr;
     __fallthrough /* fall through */;
   default:
-    rc.throw_exception();
+    MDBX_CXX20_UNLIKELY rc.throw_exception();
   case MDBX_SUCCESS:
-    handle_ = nullptr;
+    MDBX_CXX20_LIKELY handle_ = nullptr;
   }
 }
 
@@ -1220,7 +1227,7 @@ __cold env_managed::env_managed(const ::std::filesystem::path &pathname,
 
   if (op.options.nested_write_transactions &&
       !get_options().nested_write_transactions)
-    error::throw_exception(MDBX_INCOMPATIBLE);
+    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
 }
 
 __cold env_managed::env_managed(const ::std::filesystem::path &pathname,
@@ -1236,7 +1243,7 @@ __cold env_managed::env_managed(const ::std::filesystem::path &pathname,
 
   if (op.options.nested_write_transactions &&
       !get_options().nested_write_transactions)
-    error::throw_exception(MDBX_INCOMPATIBLE);
+    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
 }
 #endif /* MDBX_STD_FILESYSTEM_PATH */
 
@@ -1251,7 +1258,7 @@ __cold env_managed::env_managed(const ::std::wstring &pathname,
 
   if (op.options.nested_write_transactions &&
       !get_options().nested_write_transactions)
-    error::throw_exception(MDBX_INCOMPATIBLE);
+    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
 }
 
 __cold env_managed::env_managed(const ::std::wstring &pathname,
@@ -1267,7 +1274,7 @@ __cold env_managed::env_managed(const ::std::wstring &pathname,
 
   if (op.options.nested_write_transactions &&
       !get_options().nested_write_transactions)
-    error::throw_exception(MDBX_INCOMPATIBLE);
+    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
 }
 #endif /* Windows */
 
@@ -1281,7 +1288,7 @@ __cold env_managed::env_managed(const ::std::string &pathname,
 
   if (op.options.nested_write_transactions &&
       !get_options().nested_write_transactions)
-    error::throw_exception(MDBX_INCOMPATIBLE);
+    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
 }
 
 __cold env_managed::env_managed(const ::std::string &pathname,
@@ -1297,7 +1304,7 @@ __cold env_managed::env_managed(const ::std::string &pathname,
 
   if (op.options.nested_write_transactions &&
       !get_options().nested_write_transactions)
-    error::throw_exception(MDBX_INCOMPATIBLE);
+    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
 }
 
 //------------------------------------------------------------------------------
@@ -1312,25 +1319,25 @@ txn_managed txn::start_nested() {
 }
 
 txn_managed::~txn_managed() noexcept {
-  if (handle_)
-    error::success_or_panic(::mdbx_txn_abort(handle_), "mdbx::~txn",
-                            "mdbx_txn_abort");
+  if (MDBX_UNLIKELY(handle_))
+    MDBX_CXX20_UNLIKELY error::success_or_panic(::mdbx_txn_abort(handle_),
+                                                "mdbx::~txn", "mdbx_txn_abort");
 }
 
 void txn_managed::abort() {
   const error err = static_cast<MDBX_error_t>(::mdbx_txn_abort(handle_));
   if (MDBX_LIKELY(err.code() != MDBX_THREAD_MISMATCH))
-    handle_ = nullptr;
+    MDBX_CXX20_LIKELY handle_ = nullptr;
   if (MDBX_UNLIKELY(err.code() != MDBX_SUCCESS))
-    err.throw_exception();
+    MDBX_CXX20_UNLIKELY err.throw_exception();
 }
 
 void txn_managed::commit() {
   const error err = static_cast<MDBX_error_t>(::mdbx_txn_commit(handle_));
   if (MDBX_LIKELY(err.code() != MDBX_THREAD_MISMATCH))
-    handle_ = nullptr;
+    MDBX_CXX20_LIKELY handle_ = nullptr;
   if (MDBX_UNLIKELY(err.code() != MDBX_SUCCESS))
-    err.throw_exception();
+    MDBX_CXX20_UNLIKELY err.throw_exception();
 }
 
 //------------------------------------------------------------------------------
@@ -1394,7 +1401,7 @@ __cold ::std::ostream &operator<<(::std::ostream &out, const slice &it) {
     if (root.is_printable())
       (out << "\"").write(root.char_ptr(), root.length()) << "\"";
     else
-      out << root.base58_encode();
+      out << root.encode_base58();
     if (root.length() < it.length())
       out << "...";
   }
@@ -1422,7 +1429,7 @@ __cold ::std::ostream &operator<<(::std::ostream &out,
   }
 
   const auto bytes = (it.bytes < 0) ? out << "-",
-             size_t(-it.bytes) : size_t(it.bytes);
+             size_t(-it.bytes)      : size_t(it.bytes);
   struct {
     size_t one;
     const char *suffix;

src/mdbx_chk.c

@@ -112,7 +112,7 @@ struct problem {
 };
 
 struct problem *problems_list;
-uint64_t total_problems;
+unsigned total_problems, data_tree_problems, gc_tree_problems;
 
 static void MDBX_PRINTF_ARGS(1, 2) print(const char *msg, ...) {
   if (!quiet) {
@@ -299,14 +299,20 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
                      const size_t nentries, const size_t payload_bytes,
                      const size_t header_bytes, const size_t unused_bytes) {
   (void)ctx;
+  const bool is_gc_tree = dbi_name_or_tag == MDBX_PGWALK_GC;
   if (deep > 42) {
     problem_add("deep", deep, "too large", nullptr);
+    data_tree_problems += !is_gc_tree;
+    gc_tree_problems += is_gc_tree;
     return MDBX_CORRUPTED /* avoid infinite loop/recursion */;
   }
 
   walk_dbi_t *dbi = pagemap_lookup_dbi(dbi_name_or_tag, false);
-  if (!dbi)
+  if (!dbi) {
+    data_tree_problems += !is_gc_tree;
+    gc_tree_problems += is_gc_tree;
     return MDBX_ENOMEM;
+  }
 
   const size_t page_bytes = payload_bytes + header_bytes + unused_bytes;
   walk.pgcount += pgnumber;
@@ -319,13 +325,19 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
                 (unsigned)pagetype, deep);
     pagetype_caption = "unknown";
     dbi->pages.other += pgnumber;
+    data_tree_problems += !is_gc_tree;
+    gc_tree_problems += is_gc_tree;
     break;
   case MDBX_page_broken:
     pagetype_caption = "broken";
     dbi->pages.other += pgnumber;
+    data_tree_problems += !is_gc_tree;
+    gc_tree_problems += is_gc_tree;
     break;
   case MDBX_subpage_broken:
     pagetype_caption = "broken-subpage";
+    data_tree_problems += !is_gc_tree;
+    gc_tree_problems += is_gc_tree;
     break;
   case MDBX_page_meta:
     pagetype_caption = "meta";
@@ -375,17 +387,21 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
     bool already_used = false;
     for (unsigned n = 0; n < pgnumber; ++n) {
       uint64_t spanpgno = pgno + n;
-      if (spanpgno >= alloc_pages)
+      if (spanpgno >= alloc_pages) {
         problem_add("page", spanpgno, "wrong page-no",
                     "%s-page: %" PRIu64 " > %" PRIu64 ", deep %i",
                     pagetype_caption, spanpgno, alloc_pages, deep);
-      else if (walk.pagemap[spanpgno]) {
+        data_tree_problems += !is_gc_tree;
+        gc_tree_problems += is_gc_tree;
+      } else if (walk.pagemap[spanpgno]) {
         walk_dbi_t *coll_dbi = &walk.dbi[walk.pagemap[spanpgno] - 1];
         problem_add("page", spanpgno,
                     (branch && coll_dbi == dbi) ? "loop" : "already used",
                     "%s-page: by %s, deep %i", pagetype_caption, coll_dbi->name,
                     deep);
         already_used = true;
+        data_tree_problems += !is_gc_tree;
+        gc_tree_problems += is_gc_tree;
       } else {
         walk.pagemap[spanpgno] = (short)(dbi - walk.dbi + 1);
         dbi->pages.total += 1;
@@ -399,18 +415,26 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
 
   if (MDBX_IS_ERROR(err)) {
     problem_add("page", pgno, "invalid/corrupted", "%s-page", pagetype_caption);
+    data_tree_problems += !is_gc_tree;
+    gc_tree_problems += is_gc_tree;
   } else {
-    if (unused_bytes > page_size)
+    if (unused_bytes > page_size) {
       problem_add("page", pgno, "illegal unused-bytes",
                   "%s-page: %u < %" PRIuPTR " < %u", pagetype_caption, 0,
                   unused_bytes, envinfo.mi_dxb_pagesize);
+      data_tree_problems += !is_gc_tree;
+      gc_tree_problems += is_gc_tree;
+    }
 
     if (header_bytes < (int)sizeof(long) ||
-        (size_t)header_bytes >= envinfo.mi_dxb_pagesize - sizeof(long))
+        (size_t)header_bytes >= envinfo.mi_dxb_pagesize - sizeof(long)) {
       problem_add("page", pgno, "illegal header-length",
                   "%s-page: %" PRIuPTR " < %" PRIuPTR " < %" PRIuPTR,
                   pagetype_caption, sizeof(long), header_bytes,
                   envinfo.mi_dxb_pagesize - sizeof(long));
+      data_tree_problems += !is_gc_tree;
+      gc_tree_problems += is_gc_tree;
+    }
     if (payload_bytes < 1) {
       if (nentries > 1) {
         problem_add("page", pgno, "zero size-of-entry",
@@ -420,12 +444,16 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
           // LY: hush a misuse error
           page_bytes = page_size;
         } */
+        data_tree_problems += !is_gc_tree;
+        gc_tree_problems += is_gc_tree;
       } else {
         problem_add("page", pgno, "empty",
                     "%s-page: payload %" PRIuPTR " bytes, %" PRIuPTR
                     " entries, deep %i",
                     pagetype_caption, payload_bytes, nentries, deep);
         dbi->pages.empty += 1;
+        data_tree_problems += !is_gc_tree;
+        gc_tree_problems += is_gc_tree;
       }
     }
 
@@ -438,6 +466,8 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
                     payload_bytes, unused_bytes, deep);
         if (page_size > page_bytes)
           dbi->lost_bytes += page_size - page_bytes;
+        data_tree_problems += !is_gc_tree;
+        gc_tree_problems += is_gc_tree;
       } else {
         dbi->payload_bytes += payload_bytes + header_bytes;
         walk.total_payload_bytes += payload_bytes + header_bytes;
@@ -807,8 +837,9 @@ static int process_db(MDBX_dbi dbi_handle, char *dbi_name, visitor *handler,
       bad_data = true;
     }
 
-    if (prev_key.iov_base && !bad_data) {
-      if ((flags & MDBX_DUPFIXED) && prev_data.iov_len != data.iov_len) {
+    if (prev_key.iov_base) {
+      if (prev_data.iov_base && !bad_data && (flags & MDBX_DUPFIXED) &&
+          prev_data.iov_len != data.iov_len) {
         problem_add("entry", record_count, "different data length",
                     "%" PRIuPTR " != %" PRIuPTR, prev_data.iov_len,
                     data.iov_len);
@@ -821,11 +852,11 @@ static int process_db(MDBX_dbi dbi_handle, char *dbi_name, visitor *handler,
           ++dups;
           if ((flags & MDBX_DUPSORT) == 0) {
             problem_add("entry", record_count, "duplicated entries", nullptr);
-            if (data.iov_len == prev_data.iov_len &&
+            if (prev_data.iov_base && data.iov_len == prev_data.iov_len &&
                 memcmp(data.iov_base, prev_data.iov_base, data.iov_len) == 0) {
               problem_add("entry", record_count, "complete duplicate", nullptr);
             }
-          } else if (!bad_data) {
+          } else if (!bad_data && prev_data.iov_base) {
             cmp = mdbx_dcmp(txn, dbi_handle, &data, &prev_data);
             if (cmp == 0) {
               problem_add("entry", record_count, "complete duplicate", nullptr);
@@ -838,11 +869,6 @@ static int process_db(MDBX_dbi dbi_handle, char *dbi_name, visitor *handler,
           problem_add("entry", record_count, "wrong order of entries", nullptr);
         }
       }
-    } else if (verbose) {
-      if (flags & MDBX_INTEGERKEY)
-        print(" - fixed key-size %" PRIuPTR "\n", key.iov_len);
-      if (flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED))
-        print(" - fixed data-size %" PRIuPTR "\n", data.iov_len);
     }
 
     if (handler) {
@@ -855,10 +881,17 @@ static int process_db(MDBX_dbi dbi_handle, char *dbi_name, visitor *handler,
     key_bytes += key.iov_len;
     data_bytes += data.iov_len;
 
-    if (!bad_key)
+    if (!bad_key) {
+      if (verbose && (flags & MDBX_INTEGERKEY) && !prev_key.iov_base)
+        print(" - fixed key-size %" PRIuPTR "\n", key.iov_len);
       prev_key = key;
-    if (!bad_data)
+    }
+    if (!bad_data) {
+      if (verbose && (flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED)) &&
+          !prev_data.iov_base)
+        print(" - fixed data-size %" PRIuPTR "\n", data.iov_len);
       prev_data = data;
+    }
     rc = mdbx_cursor_get(mc, &key, &data, MDBX_NEXT);
   }
   if (rc != MDBX_NOTFOUND)
@@ -915,7 +948,7 @@ static __inline bool meta_ot(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
 
 static __inline bool meta_eq(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
                              uint64_t sign_b) {
-  if (txn_a != txn_b)
+  if (!txn_a || txn_a != txn_b)
     return false;
 
   if (SIGN_IS_STEADY(sign_a) != SIGN_IS_STEADY(sign_b))
@@ -1033,7 +1066,7 @@ int main(int argc, char *argv[]) {
   int rc;
   char *prog = argv[0];
   char *envname;
-  int problems_maindb = 0, problems_freedb = 0, problems_meta = 0;
+  unsigned problems_maindb = 0, problems_freedb = 0, problems_meta = 0;
   bool write_locked = false;
   bool turn_meta = false;
   bool force_turn_meta = false;
@@ -1114,7 +1147,6 @@ int main(int argc, char *argv[]) {
       quiet = true;
       break;
     case 'n':
-      envflags |= MDBX_NOSUBDIR;
       break;
     case 'w':
       envflags &= ~MDBX_RDONLY;
@@ -1377,11 +1409,6 @@ int main(int argc, char *argv[]) {
           "of may by large than the database itself,\n                     "
           "until it will be closed or reopened in read-write mode.\n");
 #endif
-    print(" - transactions: recent %" PRIu64 ", latter reader %" PRIu64
-          ", lag %" PRIi64 "\n",
-          envinfo.mi_recent_txnid, envinfo.mi_latter_reader_txnid,
-          envinfo.mi_recent_txnid - envinfo.mi_latter_reader_txnid);
-
     verbose_meta(0, envinfo.mi_meta0_txnid, envinfo.mi_meta0_sign,
                  envinfo.mi_bootid.meta0.x, envinfo.mi_bootid.meta0.y);
     verbose_meta(1, envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign,
@@ -1390,52 +1417,70 @@ int main(int argc, char *argv[]) {
                  envinfo.mi_bootid.meta2.x, envinfo.mi_bootid.meta2.y);
   }
 
-  if (verbose > 1)
-    print(" - performs check for meta-pages clashes\n");
-  if (meta_eq(envinfo.mi_meta0_txnid, envinfo.mi_meta0_sign,
-              envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign)) {
-    print(" ! meta-%d and meta-%d are clashed\n", 0, 1);
-    ++problems_meta;
-  }
-  if (meta_eq(envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign,
-              envinfo.mi_meta2_txnid, envinfo.mi_meta2_sign)) {
-    print(" ! meta-%d and meta-%d are clashed\n", 1, 2);
-    ++problems_meta;
-  }
-  if (meta_eq(envinfo.mi_meta2_txnid, envinfo.mi_meta2_sign,
-              envinfo.mi_meta0_txnid, envinfo.mi_meta0_sign)) {
-    print(" ! meta-%d and meta-%d are clashed\n", 2, 0);
-    ++problems_meta;
-  }
+  if (stuck_meta >= 0) {
+    if (verbose) {
+      print(" - skip checking meta-pages since the %u"
+            " is selected for verification\n",
+            stuck_meta);
+      print(" - transactions: recent %" PRIu64
+            ", selected for verification %" PRIu64 ", lag %" PRIi64 "\n",
+            envinfo.mi_recent_txnid, get_meta_txnid(stuck_meta),
+            envinfo.mi_recent_txnid - get_meta_txnid(stuck_meta));
+    }
+  } else {
+    if (verbose > 1)
+      print(" - performs check for meta-pages clashes\n");
+    if (meta_eq(envinfo.mi_meta0_txnid, envinfo.mi_meta0_sign,
+                envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign)) {
+      print(" ! meta-%d and meta-%d are clashed\n", 0, 1);
+      ++problems_meta;
+    }
+    if (meta_eq(envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign,
+                envinfo.mi_meta2_txnid, envinfo.mi_meta2_sign)) {
+      print(" ! meta-%d and meta-%d are clashed\n", 1, 2);
+      ++problems_meta;
+    }
+    if (meta_eq(envinfo.mi_meta2_txnid, envinfo.mi_meta2_sign,
+                envinfo.mi_meta0_txnid, envinfo.mi_meta0_sign)) {
+      print(" ! meta-%d and meta-%d are clashed\n", 2, 0);
+      ++problems_meta;
+    }
 
-  const unsigned steady_meta_id = meta_recent(true);
-  const uint64_t steady_meta_txnid = get_meta_txnid(steady_meta_id);
-  const unsigned weak_meta_id = meta_recent(false);
-  const uint64_t weak_meta_txnid = get_meta_txnid(weak_meta_id);
-  if (envflags & MDBX_EXCLUSIVE) {
-    if (verbose > 1)
-      print(" - performs full check recent-txn-id with meta-pages\n");
-    if (steady_meta_txnid != envinfo.mi_recent_txnid) {
-      print(" ! steady meta-%d txn-id mismatch recent-txn-id (%" PRIi64
-            " != %" PRIi64 ")\n",
-            steady_meta_id, steady_meta_txnid, envinfo.mi_recent_txnid);
-      ++problems_meta;
+    const unsigned steady_meta_id = meta_recent(true);
+    const uint64_t steady_meta_txnid = get_meta_txnid(steady_meta_id);
+    const unsigned weak_meta_id = meta_recent(false);
+    const uint64_t weak_meta_txnid = get_meta_txnid(weak_meta_id);
+    if (envflags & MDBX_EXCLUSIVE) {
+      if (verbose > 1)
+        print(" - performs full check recent-txn-id with meta-pages\n");
+      if (steady_meta_txnid != envinfo.mi_recent_txnid) {
+        print(" ! steady meta-%d txn-id mismatch recent-txn-id (%" PRIi64
+              " != %" PRIi64 ")\n",
+              steady_meta_id, steady_meta_txnid, envinfo.mi_recent_txnid);
+        ++problems_meta;
+      }
+    } else if (write_locked) {
+      if (verbose > 1)
+        print(" - performs lite check recent-txn-id with meta-pages (not a "
+              "monopolistic mode)\n");
+      if (weak_meta_txnid != envinfo.mi_recent_txnid) {
+        print(" ! weak meta-%d txn-id mismatch recent-txn-id (%" PRIi64
+              " != %" PRIi64 ")\n",
+              weak_meta_id, weak_meta_txnid, envinfo.mi_recent_txnid);
+        ++problems_meta;
+      }
+    } else if (verbose) {
+      print(" - skip check recent-txn-id with meta-pages (monopolistic or "
+            "read-write mode only)\n");
     }
-  } else if (write_locked) {
-    if (verbose > 1)
-      print(" - performs lite check recent-txn-id with meta-pages (not a "
-            "monopolistic mode)\n");
-    if (weak_meta_txnid != envinfo.mi_recent_txnid) {
-      print(" ! weak meta-%d txn-id mismatch recent-txn-id (%" PRIi64
-            " != %" PRIi64 ")\n",
-            weak_meta_id, weak_meta_txnid, envinfo.mi_recent_txnid);
-      ++problems_meta;
-    }
-  } else if (verbose) {
-    print(" - skip check recent-txn-id with meta-pages (monopolistic or "
-          "read-write mode only)\n");
+    total_problems += problems_meta;
+
+    if (verbose)
+      print(" - transactions: recent %" PRIu64 ", latter reader %" PRIu64
+            ", lag %" PRIi64 "\n",
+            envinfo.mi_recent_txnid, envinfo.mi_latter_reader_txnid,
+            envinfo.mi_recent_txnid - envinfo.mi_latter_reader_txnid);
   }
-  total_problems += problems_meta;
 
   if (!dont_traversal) {
     struct problem *saved_list;
@@ -1546,8 +1591,19 @@ int main(int argc, char *argv[]) {
 
   if (!verbose)
     print("Iterating DBIs...\n");
-  problems_maindb = process_db(~0u, /* MAIN_DBI */ nullptr, nullptr, false);
-  problems_freedb = process_db(FREE_DBI, "@GC", handle_freedb, false);
+  if (data_tree_problems) {
+    print("Skip processing %s since tree is corrupted (%u problems)\n", "@MAIN",
+          data_tree_problems);
+    problems_maindb = data_tree_problems;
+  } else
+    problems_maindb = process_db(~0u, /* MAIN_DBI */ nullptr, nullptr, false);
+
+  if (gc_tree_problems) {
+    print("Skip processing %s since tree is corrupted (%u problems)\n", "@GC",
+          gc_tree_problems);
+    problems_freedb = gc_tree_problems;
+  } else
+    problems_freedb = process_db(FREE_DBI, "@GC", handle_freedb, false);
 
   if (verbose) {
     uint64_t value = envinfo.mi_mapsize / envinfo.mi_dxb_pagesize;
@@ -1604,7 +1660,7 @@ int main(int argc, char *argv[]) {
 
   if (rc == 0 && total_problems == 1 && problems_meta == 1 && !dont_traversal &&
       (envflags & MDBX_RDONLY) == 0 && !only_subdb && stuck_meta < 0 &&
-      steady_meta_txnid < envinfo.mi_recent_txnid) {
+      get_meta_txnid(meta_recent(true)) < envinfo.mi_recent_txnid) {
     print("Perform sync-to-disk for make steady checkpoint at txn-id #%" PRIi64
           "\n",
           envinfo.mi_recent_txnid);
@@ -1674,8 +1730,8 @@ bailout:
 #endif /* !WINDOWS */
 
   if (total_problems) {
-    print("Total %" PRIu64 " error%s detected, elapsed %.3f seconds.\n",
-          total_problems, (total_problems > 1) ? "s are" : " is", elapsed);
+    print("Total %u error%s detected, elapsed %.3f seconds.\n", total_problems,
+          (total_problems > 1) ? "s are" : " is", elapsed);
     if (problems_meta || problems_maindb || problems_freedb)
       return EXIT_FAILURE_CHECK_MAJOR;
     return EXIT_FAILURE_CHECK_MINOR;

src/mdbx_drop.c

@@ -54,7 +54,9 @@ static void usage(void) {
           "usage: %s [-V] [-q] [-d] [-s name] dbpath\n"
           "  -V\t\tprint version and exit\n"
           "  -q\t\tbe quiet\n"
-          "  -d\t\tdelete the specified database, don't just empty it\n",
+          "  -d\t\tdelete the specified database, don't just empty it\n"
+          "  -s name\tdrop the specified named subDB\n"
+          "  \t\tby default empty the main DB\n",
           prog);
   exit(EXIT_FAILURE);
 }
@@ -79,11 +81,12 @@ int main(int argc, char *argv[]) {
   if (argc < 2)
     usage();
 
-  /* -d: delete the db, don't just empty it
-   * -s: drop the named subDB
-   * -V: print version and exit
-   * (default) empty the main DB */
-  while ((i = getopt(argc, argv, "ds:nV")) != EOF) {
+  while ((i = getopt(argc, argv,
+                     "d"
+                     "s:"
+                     "n"
+                     "q"
+                     "V")) != EOF) {
     switch (i) {
     case 'V':
       printf("mdbx_drop version %d.%d.%d.%d\n"
@@ -99,11 +102,13 @@ int main(int argc, char *argv[]) {
              mdbx_build.target, mdbx_build.compiler, mdbx_build.flags,
              mdbx_build.options);
       return EXIT_SUCCESS;
+    case 'q':
+      quiet = true;
+      break;
     case 'd':
       delete = true;
       break;
     case 'n':
-      envflags |= MDBX_NOSUBDIR;
       break;
     case 's':
       subname = optarg;
@@ -130,11 +135,12 @@ int main(int argc, char *argv[]) {
 #endif /* !WINDOWS */
 
   envname = argv[optind];
-  if (!quiet)
+  if (!quiet) {
     printf("mdbx_drop %s (%s, T-%s)\nRunning for %s/%s...\n",
            mdbx_version.git.describe, mdbx_version.git.datetime,
            mdbx_version.git.tree, envname, subname ? subname : "@MAIN");
-  fflush(nullptr);
+    fflush(nullptr);
+  }
 
   rc = mdbx_env_create(&env);
   if (unlikely(rc != MDBX_SUCCESS)) {

src/mdbx_dump.c

@@ -101,7 +101,9 @@ static void dumpval(MDBX_val *v) {
 bool quiet = false, rescue = false;
 const char *prog;
 static void error(const char *func, int rc) {
-  fprintf(stderr, "%s: %s() error %d %s\n", prog, func, rc, mdbx_strerror(rc));
+  if (!quiet)
+    fprintf(stderr, "%s: %s() error %d %s\n", prog, func, rc,
+            mdbx_strerror(rc));
 }
 
 /* Dump in BDB-compatible format */
@@ -216,17 +218,17 @@ static int dump_sdb(MDBX_txn *txn, MDBX_dbi dbi, char *name) {
 
 static void usage(void) {
   fprintf(stderr,
-          "usage: %s [-V] [-q] [-f file] [-l] [-p] [-a|-s subdb] [-r] "
+          "usage: %s [-V] [-q] [-f file] [-l] [-p] [-r] [-a|-s subdb] "
           "dbpath\n"
           "  -V\t\tprint version and exit\n"
           "  -q\t\tbe quiet\n"
           "  -f\t\twrite to file instead of stdout\n"
           "  -l\t\tlist subDBs and exit\n"
           "  -p\t\tuse printable characters\n"
-          "  -a\t\tdump main DB and all subDBs,\n"
-          "    \t\tby default dump only the main DB\n"
-          "  -s\t\tdump only the named subDB\n"
-          "  -r\t\trescue mode (ignore errors to dump corrupted DB)\n",
+          "  -r\t\trescue mode (ignore errors to dump corrupted DB)\n"
+          "  -a\t\tdump main DB and all subDBs\n"
+          "  -s name\tdump only the specified named subDB\n"
+          "  \t\tby default dump only the main DB\n",
           prog);
   exit(EXIT_FAILURE);
 }
@@ -294,7 +296,6 @@ int main(int argc, char *argv[]) {
       }
       break;
     case 'n':
-      envflags |= MDBX_NOSUBDIR;
       break;
     case 'p':
       mode |= PRINT;
@@ -431,8 +432,9 @@ int main(int argc, char *argv[]) {
           if (unlikely(rc != MDBX_SUCCESS)) {
             if (!rescue)
               break;
-            fprintf(stderr, "%s: %s: ignore %s for `%s` and continue\n", prog,
-                    envname, mdbx_strerror(rc), subname);
+            if (!quiet)
+              fprintf(stderr, "%s: %s: ignore %s for `%s` and continue\n", prog,
+                      envname, mdbx_strerror(rc), subname);
             /* Here is a hack for rescue mode, don't do that:
              *  - we should restart transaction in case error due
              *    database corruption;
@@ -466,8 +468,9 @@ int main(int argc, char *argv[]) {
     if (have_raw && (!count /* || rescue */))
       rc = dump_sdb(txn, MAIN_DBI, nullptr);
     else if (!count) {
-      fprintf(stderr, "%s: %s does not contain multiple databases\n", prog,
-              envname);
+      if (!quiet)
+        fprintf(stderr, "%s: %s does not contain multiple databases\n", prog,
+                envname);
       rc = MDBX_NOTFOUND;
     }
   } else {
@@ -480,7 +483,8 @@ int main(int argc, char *argv[]) {
   case MDBX_SUCCESS:
     break;
   case MDBX_EINTR:
-    fprintf(stderr, "Interrupted by signal/user\n");
+    if (!quiet)
+      fprintf(stderr, "Interrupted by signal/user\n");
     break;
   default:
     if (unlikely(rc != MDBX_SUCCESS))

src/mdbx_load.c

@@ -485,7 +485,7 @@ static void usage(void) {
           "  -a\t\tappend records in input order (required for custom "
           "comparators)\n"
           "  -f file\tread from file instead of stdin\n"
-          "  -s name\tload into named subDB\n"
+          "  -s name\tload into specified named subDB\n"
           "  -N\t\tdon't overwrite existing records when loading, just skip "
           "ones\n"
           "  -p\t\tpurge subDB before loading\n"

src/mdbx_stat.c

@@ -54,14 +54,16 @@ static void print_stat(MDBX_stat *ms) {
 
 static void usage(const char *prog) {
   fprintf(stderr,
-          "usage: %s [-V] [-e] [-f[f[f]]] [-r[r]] [-a|-s name] dbpath\n"
+          "usage: %s [-V] [-q] [-e] [-f[f[f]]] [-r[r]] [-a|-s name] dbpath\n"
           "  -V\t\tprint version and exit\n"
+          "  -q\t\tbe quiet\n"
+          "  -p\t\tshow statistics of page operations for current session\n"
           "  -e\t\tshow whole DB info\n"
           "  -f\t\tshow GC info\n"
           "  -r\t\tshow readers\n"
           "  -a\t\tprint stat of main DB and all subDBs\n"
-          "  \t\t(default) print stat of only the main DB\n"
-          "  -s name\tprint stat of only the named subDB\n",
+          "  -s name\tprint stat of only the specified named subDB\n"
+          "  \t\tby default print stat of only the main DB\n",
           prog);
   exit(EXIT_FAILURE);
 }
@@ -88,12 +90,15 @@ static int reader_list_func(void *ctx, int num, int slot, mdbx_pid_t pid,
 }
 
 const char *prog;
+bool quiet = false;
 static void error(const char *func, int rc) {
-  fprintf(stderr, "%s: %s() error %d %s\n", prog, func, rc, mdbx_strerror(rc));
+  if (!quiet)
+    fprintf(stderr, "%s: %s() error %d %s\n", prog, func, rc,
+            mdbx_strerror(rc));
 }
 
 int main(int argc, char *argv[]) {
-  int o, rc;
+  int opt, rc;
   MDBX_env *env;
   MDBX_txn *txn;
   MDBX_dbi dbi;
@@ -101,20 +106,23 @@ int main(int argc, char *argv[]) {
   prog = argv[0];
   char *envname;
   char *subname = nullptr;
-  int alldbs = 0, envinfo = 0, envflags = 0, freinfo = 0, rdrinfo = 0;
+  bool alldbs = false, envinfo = false, pgop = false;
+  int freinfo = 0, rdrinfo = 0;
 
   if (argc < 2)
     usage(prog);
 
-  while ((o = getopt(argc, argv,
-                     "V"
-                     "a"
-                     "e"
-                     "f"
-                     "n"
-                     "r"
-                     "s:")) != EOF) {
-    switch (o) {
+  while ((opt = getopt(argc, argv,
+                       "V"
+                       "q"
+                       "p"
+                       "a"
+                       "e"
+                       "f"
+                       "n"
+                       "r"
+                       "s:")) != EOF) {
+    switch (opt) {
     case 'V':
       printf("mdbx_stat version %d.%d.%d.%d\n"
              " - source: %s %s, commit %s, tree %s\n"
@@ -129,22 +137,27 @@ int main(int argc, char *argv[]) {
              mdbx_build.target, mdbx_build.compiler, mdbx_build.flags,
              mdbx_build.options);
       return EXIT_SUCCESS;
+    case 'q':
+      quiet = true;
+      break;
+    case 'p':
+      pgop = true;
+      break;
     case 'a':
       if (subname)
         usage(prog);
-      alldbs++;
+      alldbs = true;
       break;
     case 'e':
-      envinfo++;
+      envinfo = true;
       break;
     case 'f':
-      freinfo++;
+      freinfo += 1;
       break;
     case 'n':
-      envflags |= MDBX_NOSUBDIR;
       break;
     case 'r':
-      rdrinfo++;
+      rdrinfo += 1;
       break;
     case 's':
       if (alldbs)
@@ -174,10 +187,12 @@ int main(int argc, char *argv[]) {
 
   envname = argv[optind];
   envname = argv[optind];
-  printf("mdbx_stat %s (%s, T-%s)\nRunning for %s...\n",
-         mdbx_version.git.describe, mdbx_version.git.datetime,
-         mdbx_version.git.tree, envname);
-  fflush(nullptr);
+  if (!quiet) {
+    printf("mdbx_stat %s (%s, T-%s)\nRunning for %s...\n",
+           mdbx_version.git.describe, mdbx_version.git.datetime,
+           mdbx_version.git.tree, envname);
+    fflush(nullptr);
+  }
 
   rc = mdbx_env_create(&env);
   if (unlikely(rc != MDBX_SUCCESS)) {
@@ -193,7 +208,7 @@ int main(int argc, char *argv[]) {
     }
   }
 
-  rc = mdbx_env_open(env, envname, envflags | MDBX_RDONLY, 0);
+  rc = mdbx_env_open(env, envname, MDBX_RDONLY, 0);
   if (unlikely(rc != MDBX_SUCCESS)) {
     error("mdbx_env_open", rc);
     goto env_close;
@@ -205,7 +220,7 @@ int main(int argc, char *argv[]) {
     goto txn_abort;
   }
 
-  if (envinfo || freinfo) {
+  if (envinfo || freinfo || pgop) {
     rc = mdbx_env_info_ex(env, txn, &mei, sizeof(mei));
     if (unlikely(rc != MDBX_SUCCESS)) {
       error("mdbx_env_info_ex", rc);
@@ -216,6 +231,33 @@ int main(int argc, char *argv[]) {
     memset(&mei, 0, sizeof(mei));
   }
 
+  if (pgop) {
+    printf("Page Operations (for current session):\n");
+    printf("      New: %8" PRIu64 "\t// quantity of a new pages added\n",
+           mei.mi_pgop_stat.newly);
+    printf("      CoW: %8" PRIu64
+           "\t// quantity of pages copied for altering\n",
+           mei.mi_pgop_stat.cow);
+    printf("    Clone: %8" PRIu64 "\t// quantity of parent's dirty pages "
+           "clones for nested transactions\n",
+           mei.mi_pgop_stat.clone);
+    printf("    Split: %8" PRIu64
+           "\t// page splits during insertions or updates\n",
+           mei.mi_pgop_stat.split);
+    printf("    Merge: %8" PRIu64
+           "\t// page merges during deletions or updates\n",
+           mei.mi_pgop_stat.merge);
+    printf("    Spill: %8" PRIu64 "\t// quantity of spilled/ousted `dirty` "
+           "pages during large transactions\n",
+           mei.mi_pgop_stat.spill);
+    printf("  Unspill: %8" PRIu64 "\t// quantity of unspilled/redone `dirty` "
+           "pages during large transactions\n",
+           mei.mi_pgop_stat.unspill);
+    printf("      WOP: %8" PRIu64
+           "\t// number of explicit write operations (not a pages) to a disk\n",
+           mei.mi_pgop_stat.wops);
+  }
+
   if (envinfo) {
     printf("Environment Info\n");
     printf("  Pagesize: %u\n", mei.mi_dxb_pagesize);
@@ -356,7 +398,8 @@ int main(int argc, char *argv[]) {
     case MDBX_NOTFOUND:
       break;
     case MDBX_EINTR:
-      fprintf(stderr, "Interrupted by signal/user\n");
+      if (!quiet)
+        fprintf(stderr, "Interrupted by signal/user\n");
       goto txn_abort;
     default:
       error("mdbx_cursor_get", rc);
@@ -462,7 +505,8 @@ int main(int argc, char *argv[]) {
   case MDBX_NOTFOUND:
     break;
   case MDBX_EINTR:
-    fprintf(stderr, "Interrupted by signal/user\n");
+    if (!quiet)
+      fprintf(stderr, "Interrupted by signal/user\n");
     break;
   default:
     if (unlikely(rc != MDBX_SUCCESS))

src/options.h

@@ -39,18 +39,18 @@
 #else
 #define MDBX_ENV_CHECKPID 1
 #endif
-#define MDBX_ENV_CHECKPID_CONFIG "AUTO=" STRINGIFY(MDBX_ENV_CHECKPID)
+#define MDBX_ENV_CHECKPID_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_ENV_CHECKPID)
 #else
-#define MDBX_ENV_CHECKPID_CONFIG STRINGIFY(MDBX_ENV_CHECKPID)
+#define MDBX_ENV_CHECKPID_CONFIG MDBX_STRINGIFY(MDBX_ENV_CHECKPID)
 #endif /* MDBX_ENV_CHECKPID */
 
 /** Controls checking transaction owner thread against misuse transactions from
  * other threads. */
 #ifndef MDBX_TXN_CHECKOWNER
 #define MDBX_TXN_CHECKOWNER 1
-#define MDBX_TXN_CHECKOWNER_CONFIG "AUTO=" STRINGIFY(MDBX_TXN_CHECKOWNER)
+#define MDBX_TXN_CHECKOWNER_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_TXN_CHECKOWNER)
 #else
-#define MDBX_TXN_CHECKOWNER_CONFIG STRINGIFY(MDBX_TXN_CHECKOWNER)
+#define MDBX_TXN_CHECKOWNER_CONFIG MDBX_STRINGIFY(MDBX_TXN_CHECKOWNER)
 #endif /* MDBX_TXN_CHECKOWNER */
 
 /** Does a system have battery-backed Real-Time Clock or just a fake. */
@@ -61,9 +61,9 @@
 #else
 #define MDBX_TRUST_RTC 1
 #endif
-#define MDBX_TRUST_RTC_CONFIG "AUTO=" STRINGIFY(MDBX_TRUST_RTC)
+#define MDBX_TRUST_RTC_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_TRUST_RTC)
 #else
-#define MDBX_TRUST_RTC_CONFIG STRINGIFY(MDBX_TRUST_RTC)
+#define MDBX_TRUST_RTC_CONFIG MDBX_STRINGIFY(MDBX_TRUST_RTC)
 #endif /* MDBX_TRUST_RTC */
 
 /** Controls online database auto-compactification during write-transactions. */
@@ -238,9 +238,9 @@
 #else
 #define MDBX_LOCKING MDBX_LOCKING_SYSV
 #endif
-#define MDBX_LOCKING_CONFIG "AUTO=" STRINGIFY(MDBX_LOCKING)
+#define MDBX_LOCKING_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_LOCKING)
 #else
-#define MDBX_LOCKING_CONFIG STRINGIFY(MDBX_LOCKING)
+#define MDBX_LOCKING_CONFIG MDBX_STRINGIFY(MDBX_LOCKING)
 #endif /* MDBX_LOCKING */
 #endif /* !Windows */
 
@@ -253,9 +253,9 @@
 #else
 #define MDBX_USE_OFDLOCKS 0
 #endif
-#define MDBX_USE_OFDLOCKS_CONFIG "AUTO=" STRINGIFY(MDBX_USE_OFDLOCKS)
+#define MDBX_USE_OFDLOCKS_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_USE_OFDLOCKS)
 #else
-#define MDBX_USE_OFDLOCKS_CONFIG STRINGIFY(MDBX_USE_OFDLOCKS)
+#define MDBX_USE_OFDLOCKS_CONFIG MDBX_STRINGIFY(MDBX_USE_OFDLOCKS)
 #endif /* MDBX_USE_OFDLOCKS */
 
 /** Advanced: Using sendfile() syscall (autodetection by default). */
@@ -326,9 +326,9 @@
 #else
 #define MDBX_64BIT_ATOMIC 0
 #endif
-#define MDBX_64BIT_ATOMIC_CONFIG "AUTO=" STRINGIFY(MDBX_64BIT_ATOMIC)
+#define MDBX_64BIT_ATOMIC_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_64BIT_ATOMIC)
 #else
-#define MDBX_64BIT_ATOMIC_CONFIG STRINGIFY(MDBX_64BIT_ATOMIC)
+#define MDBX_64BIT_ATOMIC_CONFIG MDBX_STRINGIFY(MDBX_64BIT_ATOMIC)
 #endif /* MDBX_64BIT_ATOMIC */
 
 #ifndef MDBX_64BIT_CAS
@@ -355,9 +355,9 @@
 #else
 #define MDBX_64BIT_CAS MDBX_64BIT_ATOMIC
 #endif
-#define MDBX_64BIT_CAS_CONFIG "AUTO=" STRINGIFY(MDBX_64BIT_CAS)
+#define MDBX_64BIT_CAS_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_64BIT_CAS)
 #else
-#define MDBX_64BIT_CAS_CONFIG STRINGIFY(MDBX_64BIT_CAS)
+#define MDBX_64BIT_CAS_CONFIG MDBX_STRINGIFY(MDBX_64BIT_CAS)
 #endif /* MDBX_64BIT_CAS */
 
 #ifndef MDBX_UNALIGNED_OK

src/osal.c

@@ -217,7 +217,7 @@ __extern_C void __assert(const char *function, const char *file, int line,
 
 #if !defined(__ANDROID_API__) || MDBX_DEBUG
 
-void __cold mdbx_assert_fail(const MDBX_env *env, const char *msg,
+__cold void mdbx_assert_fail(const MDBX_env *env, const char *msg,
                              const char *func, int line) {
 #if MDBX_DEBUG
   if (env && env->me_assert_func) {
@@ -1329,6 +1329,7 @@ static int mdbx_check_fs_local(mdbx_filehandle_t handle, int flags) {
          strncasecmp("cifs", name, name_len) == 0 ||
          strncasecmp("ncpfs", name, name_len) == 0 ||
          strncasecmp("smbfs", name, name_len) == 0 ||
+         strcasecmp("9P" /* WSL2 */, name) == 0 ||
          ((name_len > 3 && strncasecmp("fuse", name, 4) == 0) &&
           strncasecmp("fuseblk", name, name_len) != 0)) &&
         !(flags & MDBX_EXCLUSIVE))
@@ -1376,6 +1377,36 @@ static int mdbx_check_fs_local(mdbx_filehandle_t handle, int flags) {
   return MDBX_SUCCESS;
 }
 
+static int check_mmap_limit(const size_t limit) {
+  const bool should_check =
+#if defined(__SANITIZE_ADDRESS__)
+      true;
+#else
+      RUNNING_ON_VALGRIND;
+#endif /* __SANITIZE_ADDRESS__ */
+
+  if (should_check) {
+    intptr_t pagesize, total_ram_pages, avail_ram_pages;
+    int err =
+        mdbx_get_sysraminfo(&pagesize, &total_ram_pages, &avail_ram_pages);
+    if (unlikely(err != MDBX_SUCCESS))
+      return err;
+
+    const int log2page = log2n_powerof2(pagesize);
+    if ((limit >> (log2page + 7)) > (size_t)total_ram_pages ||
+        (limit >> (log2page + 6)) > (size_t)avail_ram_pages) {
+      mdbx_error(
+          "%s (%zu pages) is too large for available (%zu pages) or total "
+          "(%zu pages) system RAM",
+          "database upper size limit", limit >> log2page, avail_ram_pages,
+          total_ram_pages);
+      return MDBX_TOO_LARGE;
+    }
+  }
+
+  return MDBX_SUCCESS;
+}
+
 MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,
                                  const size_t size, const size_t limit,
                                  const unsigned options) {
@@ -1383,34 +1414,34 @@ MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,
   map->limit = 0;
   map->current = 0;
   map->address = nullptr;
+  map->filesize = 0;
 #if defined(_WIN32) || defined(_WIN64)
   map->section = NULL;
-  map->filesize = 0;
 #endif /* Windows */
 
   int err = mdbx_check_fs_local(map->fd, flags);
   if (unlikely(err != MDBX_SUCCESS))
     return err;
 
+  err = check_mmap_limit(limit);
+  if (unlikely(err != MDBX_SUCCESS))
+    return err;
+
   if ((flags & MDBX_RDONLY) == 0 && (options & MMAP_OPTION_TRUNCATE) != 0) {
     err = mdbx_ftruncate(map->fd, size);
     if (err != MDBX_SUCCESS)
       return err;
-#if defined(_WIN32) || defined(_WIN64)
     map->filesize = size;
-#else
+#if !(defined(_WIN32) || defined(_WIN64))
     map->current = size;
-#endif /* ! Windows */
+#endif /* !Windows */
   } else {
-    uint64_t filesize = 0;
-    err = mdbx_filesize(map->fd, &filesize);
+    err = mdbx_filesize(map->fd, &map->filesize);
     if (err != MDBX_SUCCESS)
       return err;
-#if defined(_WIN32) || defined(_WIN64)
-    map->filesize = filesize;
-#else
-    map->current = (filesize > limit) ? limit : (size_t)filesize;
-#endif /* ! Windows */
+#if !(defined(_WIN32) || defined(_WIN64))
+    map->current = (map->filesize > limit) ? limit : (size_t)map->filesize;
+#endif /* !Windows */
   }
 
 #if defined(_WIN32) || defined(_WIN64)
@@ -1430,8 +1461,9 @@ MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,
   if (!NT_SUCCESS(err))
     return ntstatus2errcode(err);
 
-  SIZE_T ViewSize =
-      (flags & MDBX_RDONLY) ? 0 : mdbx_RunningUnderWine() ? size : limit;
+  SIZE_T ViewSize = (flags & MDBX_RDONLY)     ? 0
+                    : mdbx_RunningUnderWine() ? size
+                                              : limit;
   err = NtMapViewOfSection(
       map->section, GetCurrentProcess(), &map->address,
       /* ZeroBits */ 0,
@@ -1507,7 +1539,7 @@ MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,
 #endif /* ! Windows */
 
   VALGRIND_MAKE_MEM_DEFINED(map->address, map->current);
-  ASAN_UNPOISON_MEMORY_REGION(map->address, map->current);
+  MDBX_ASAN_UNPOISON_MEMORY_REGION(map->address, map->current);
   return MDBX_SUCCESS;
 }
 
@@ -1516,7 +1548,10 @@ MDBX_INTERNAL_FUNC int mdbx_munmap(mdbx_mmap_t *map) {
   /* Unpoisoning is required for ASAN to avoid false-positive diagnostic
    * when this memory will re-used by malloc or another mmapping.
    * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203 */
-  ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);
+  MDBX_ASAN_UNPOISON_MEMORY_REGION(map->address,
+                                   (map->filesize && map->filesize < map->limit)
+                                       ? map->filesize
+                                       : map->limit);
 #if defined(_WIN32) || defined(_WIN64)
   if (map->section)
     NtClose(map->section);
@@ -1534,8 +1569,8 @@ MDBX_INTERNAL_FUNC int mdbx_munmap(mdbx_mmap_t *map) {
   return MDBX_SUCCESS;
 }
 
-MDBX_INTERNAL_FUNC int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t size,
-                                    size_t limit, const bool may_move) {
+MDBX_INTERNAL_FUNC int mdbx_mresize(const int flags, mdbx_mmap_t *map,
+                                    size_t size, size_t limit) {
   assert(size <= limit);
 #if defined(_WIN32) || defined(_WIN64)
   assert(size != map->current || limit != map->limit || size < map->filesize);
@@ -1558,6 +1593,10 @@ MDBX_INTERNAL_FUNC int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t size,
   }
 
   if (limit > map->limit) {
+    err = check_mmap_limit(limit);
+    if (unlikely(err != MDBX_SUCCESS))
+      return err;
+
     /* check ability of address space for growth before unmap */
     PVOID BaseAddress = (PBYTE)map->address + map->limit;
     SIZE_T RegionSize = limit - map->limit;
@@ -1579,6 +1618,13 @@ MDBX_INTERNAL_FUNC int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t size,
    *  - change size of mapped view;
    *  - extend read-only mapping;
    * Therefore we should unmap/map entire section. */
+  if ((flags & MDBX_MRESIZE_MAY_UNMAP) == 0)
+    return MDBX_RESULT_TRUE;
+
+  /* Unpoisoning is required for ASAN to avoid false-positive diagnostic
+   * when this memory will re-used by malloc or another mmapping.
+   * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203 */
+  MDBX_ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);
   status = NtUnmapViewOfSection(GetCurrentProcess(), map->address);
   if (!NT_SUCCESS(status))
     return ntstatus2errcode(status);
@@ -1614,7 +1660,7 @@ retry_file_and_section:
     if (status != (NTSTATUS) /* STATUS_CONFLICTING_ADDRESSES */ 0xC0000018)
       goto bailout_ntstatus /* no way to recovery */;
 
-    if (may_move)
+    if (flags & MDBX_MRESIZE_MAY_MOVE)
       /* the base address could be changed */
       map->address = NULL;
   }
@@ -1672,7 +1718,7 @@ retry_mapview:;
 
   if (!NT_SUCCESS(status)) {
     if (status == (NTSTATUS) /* STATUS_CONFLICTING_ADDRESSES */ 0xC0000018 &&
-        map->address && may_move) {
+        map->address && (flags & MDBX_MRESIZE_MAY_MOVE) != 0) {
       /* try remap at another base address */
       map->address = NULL;
       goto retry_mapview;
@@ -1683,7 +1729,7 @@ retry_mapview:;
     if (map->address && (size != map->current || limit != map->limit)) {
       /* try remap with previously size and limit,
        * but will return MDBX_UNABLE_EXTEND_MAPSIZE on success */
-      rc = MDBX_UNABLE_EXTEND_MAPSIZE;
+      rc = (limit > map->limit) ? MDBX_UNABLE_EXTEND_MAPSIZE : MDBX_RESULT_TRUE;
       size = map->current;
       ReservedSize = limit = map->limit;
       goto retry_file_and_section;
@@ -1699,40 +1745,62 @@ retry_mapview:;
 
 #else /* Windows */
 
-  uint64_t filesize = 0;
-  int rc = mdbx_filesize(map->fd, &filesize);
+  map->filesize = 0;
+  int rc = mdbx_filesize(map->fd, &map->filesize);
   if (rc != MDBX_SUCCESS)
     return rc;
 
   if (flags & MDBX_RDONLY) {
-    map->current = (filesize > limit) ? limit : (size_t)filesize;
+    map->current = (map->filesize > limit) ? limit : (size_t)map->filesize;
     if (map->current != size)
-      rc = MDBX_UNABLE_EXTEND_MAPSIZE;
-  } else if (filesize != size) {
-    rc = mdbx_ftruncate(map->fd, size);
-    if (rc != MDBX_SUCCESS)
-      return rc;
+      rc =
+          (size > map->current) ? MDBX_UNABLE_EXTEND_MAPSIZE : MDBX_RESULT_TRUE;
+  } else {
+    if (map->filesize != size) {
+      rc = mdbx_ftruncate(map->fd, size);
+      if (rc != MDBX_SUCCESS)
+        return rc;
+      map->filesize = size;
+    }
+
+    if (map->current > size) {
+      /* Clearing asan's bitmask for the region which released in shrinking,
+       * since:
+       *  - after the shrinking we will get an exception when accessing
+       *    this region and (therefore) do not need the help of ASAN.
+       *  - this allows us to clear the mask only within the file size
+       *    when closing the mapping. */
+      MDBX_ASAN_UNPOISON_MEMORY_REGION(
+          (char *)map->address + size,
+          ((map->current < map->limit) ? map->current : map->limit) - size);
+    }
     map->current = size;
   }
 
   if (limit == map->limit)
-    return MDBX_SUCCESS;
+    return rc;
 
   if (limit < map->limit) {
     /* unmap an excess at end of mapping. */
+    // coverity[offset_free : FALSE]
     if (unlikely(munmap(map->dxb + limit, map->limit - limit)))
       return errno;
     map->limit = limit;
-    return MDBX_SUCCESS;
+    return rc;
   }
 
+  int err = check_mmap_limit(limit);
+  if (unlikely(err != MDBX_SUCCESS))
+    return err;
+
   assert(limit > map->limit);
   uint8_t *ptr = MAP_FAILED;
 
 #if defined(MREMAP_MAYMOVE)
-  ptr = mremap(map->address, map->limit, limit, may_move ? MREMAP_MAYMOVE : 0);
+  ptr = mremap(map->address, map->limit, limit,
+               (flags & MDBX_MRESIZE_MAY_MOVE) ? MREMAP_MAYMOVE : 0);
   if (ptr == MAP_FAILED) {
-    const int err = errno;
+    err = errno;
     switch (err) {
     default:
       return err;
@@ -1763,7 +1831,7 @@ retry_mapview:;
         return errno;
       ptr = MAP_FAILED;
     } else {
-      const int err = errno;
+      err = errno;
       switch (err) {
       default:
         return err;
@@ -1779,7 +1847,7 @@ retry_mapview:;
 
   if (ptr == MAP_FAILED) {
     /* unmap and map again whole region */
-    if (!may_move) {
+    if ((flags & MDBX_MRESIZE_MAY_UNMAP) == 0) {
       /* TODO: Perhaps here it is worth to implement suspend/resume threads
        * and perform unmap/map as like for Windows. */
       return MDBX_UNABLE_EXTEND_MAPSIZE;
@@ -1788,16 +1856,44 @@ retry_mapview:;
     if (unlikely(munmap(map->address, map->limit)))
       return errno;
 
-    ptr = mmap(map->address, limit, mmap_prot, mmap_flags, map->fd, 0);
+    // coverity[pass_freed_arg : FALSE]
+    ptr = mmap(map->address, limit, mmap_prot,
+               (flags & MDBX_MRESIZE_MAY_MOVE)
+                   ? mmap_flags
+                   : mmap_flags | (MAP_FIXED_NOREPLACE ? MAP_FIXED_NOREPLACE
+                                                       : MAP_FIXED),
+               map->fd, 0);
+    if (MAP_FIXED_NOREPLACE != 0 && MAP_FIXED_NOREPLACE != MAP_FIXED &&
+        unlikely(ptr == MAP_FAILED) && !(flags & MDBX_MRESIZE_MAY_MOVE) &&
+        errno == /* kernel don't support MAP_FIXED_NOREPLACE */ EINVAL)
+      // coverity[pass_freed_arg : FALSE]
+      ptr = mmap(map->address, limit, mmap_prot, mmap_flags | MAP_FIXED,
+                 map->fd, 0);
+
     if (unlikely(ptr == MAP_FAILED)) {
-      ptr = mmap(map->address, map->limit, mmap_prot, mmap_flags, map->fd, 0);
+      /* try to restore prev mapping */
+      // coverity[pass_freed_arg : FALSE]
+      ptr = mmap(map->address, map->limit, mmap_prot,
+                 (flags & MDBX_MRESIZE_MAY_MOVE)
+                     ? mmap_flags
+                     : mmap_flags | (MAP_FIXED_NOREPLACE ? MAP_FIXED_NOREPLACE
+                                                         : MAP_FIXED),
+                 map->fd, 0);
+      if (MAP_FIXED_NOREPLACE != 0 && MAP_FIXED_NOREPLACE != MAP_FIXED &&
+          unlikely(ptr == MAP_FAILED) && !(flags & MDBX_MRESIZE_MAY_MOVE) &&
+          errno == /* kernel don't support MAP_FIXED_NOREPLACE */ EINVAL)
+        // coverity[pass_freed_arg : FALSE]
+        ptr = mmap(map->address, map->limit, mmap_prot, mmap_flags | MAP_FIXED,
+                   map->fd, 0);
       if (unlikely(ptr == MAP_FAILED)) {
         VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);
         /* Unpoisoning is required for ASAN to avoid false-positive diagnostic
          * when this memory will re-used by malloc or another mmapping.
          * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203
          */
-        ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);
+        MDBX_ASAN_UNPOISON_MEMORY_REGION(
+            map->address,
+            (map->current < map->limit) ? map->current : map->limit);
         map->limit = 0;
         map->current = 0;
         map->address = nullptr;
@@ -1813,12 +1909,12 @@ retry_mapview:;
     VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);
     /* Unpoisoning is required for ASAN to avoid false-positive diagnostic
      * when this memory will re-used by malloc or another mmapping.
-     * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203
-     */
-    ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);
+     * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203 */
+    MDBX_ASAN_UNPOISON_MEMORY_REGION(
+        map->address, (map->current < map->limit) ? map->current : map->limit);
 
     VALGRIND_MAKE_MEM_DEFINED(ptr, map->current);
-    ASAN_UNPOISON_MEMORY_REGION(ptr, map->current);
+    MDBX_ASAN_UNPOISON_MEMORY_REGION(ptr, map->current);
     map->address = ptr;
   }
   map->limit = limit;
@@ -1840,7 +1936,7 @@ retry_mapview:;
 
 /*----------------------------------------------------------------------------*/
 
-MDBX_INTERNAL_FUNC __cold void mdbx_osal_jitter(bool tiny) {
+__cold MDBX_INTERNAL_FUNC void mdbx_osal_jitter(bool tiny) {
   for (;;) {
 #if defined(_M_IX86) || defined(_M_X64) || defined(__i386__) ||                \
     defined(__x86_64__)
@@ -1868,7 +1964,7 @@ MDBX_INTERNAL_FUNC __cold void mdbx_osal_jitter(bool tiny) {
 #elif defined(__APPLE__) || defined(__MACH__)
 #include <mach/mach_time.h>
 #elif defined(__linux__) || defined(__gnu_linux__)
-static __cold clockid_t choice_monoclock(void) {
+__cold static clockid_t choice_monoclock(void) {
   struct timespec probe;
 #if defined(CLOCK_BOOTTIME)
   if (clock_gettime(CLOCK_BOOTTIME, &probe) == 0)
@@ -1908,7 +2004,8 @@ mdbx_osal_16dot16_to_monotime(uint32_t seconds_16dot16) {
 #else
   const uint64_t ratio = UINT64_C(1000000000);
 #endif
-  return (ratio * seconds_16dot16 + 32768) >> 16;
+  const uint64_t ret = (ratio * seconds_16dot16 + 32768) >> 16;
+  return likely(ret || seconds_16dot16 == 0) ? ret : /* fix underflow */ 1;
 }
 
 MDBX_INTERNAL_FUNC uint32_t mdbx_osal_monotime_to_16dot16(uint64_t monotime) {
@@ -1920,13 +2017,15 @@ MDBX_INTERNAL_FUNC uint32_t mdbx_osal_monotime_to_16dot16(uint64_t monotime) {
     if (monotime > limit)
       return UINT32_MAX;
   }
+  const uint32_t ret =
 #if defined(_WIN32) || defined(_WIN64)
-  return (uint32_t)((monotime << 16) / performance_frequency.QuadPart);
+      (uint32_t)((monotime << 16) / performance_frequency.QuadPart);
 #elif defined(__APPLE__) || defined(__MACH__)
-  return (uint32_t)((monotime << 16) / ratio_16dot16_to_monotine);
+      (uint32_t)((monotime << 16) / ratio_16dot16_to_monotine);
 #else
-  return (uint32_t)(monotime * 128 / 1953125);
+      (uint32_t)(monotime * 128 / 1953125);
 #endif
+  return likely(ret || monotime == 0) ? ret : /* fix underflow */ 1;
 }
 
 MDBX_INTERNAL_FUNC uint64_t mdbx_osal_monotime(void) {
@@ -2057,8 +2156,8 @@ static LSTATUS mdbx_RegGetValue(HKEY hKey, LPCSTR lpSubKey, LPCSTR lpValue,
 }
 #endif
 
-static __cold __maybe_unused bool bootid_parse_uuid(bin128_t *s, const void *p,
-                                                    const size_t n) {
+__cold MDBX_MAYBE_UNUSED static bool
+bootid_parse_uuid(bin128_t *s, const void *p, const size_t n) {
   if (n > 31) {
     unsigned bits = 0;
     for (unsigned i = 0; i < n; ++i) /* try parse an UUID in text form */ {
@@ -2173,7 +2272,7 @@ __cold MDBX_INTERNAL_FUNC bin128_t mdbx_osal_bootid(void) {
     if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_MicrosoftCryptography,
                          "MachineGuid", &buf.MachineGuid,
                          &len) == ERROR_SUCCESS &&
-        len > 42 && len < sizeof(buf))
+        len < sizeof(buf))
       got_machineid = bootid_parse_uuid(&bin, &buf.MachineGuid, len);
 
     if (!got_machineid) {
@@ -2237,12 +2336,16 @@ __cold MDBX_INTERNAL_FUNC bin128_t mdbx_osal_bootid(void) {
         0x03 /* SystemTmeOfDayInformation */, &buf.SysTimeOfDayInfo,
         sizeof(buf.SysTimeOfDayInfo), &len);
     if (NT_SUCCESS(status) &&
-        len >= offsetof(union buf, SysTimeOfDayInfoHacked.BootTime) +
-                   sizeof(buf.SysTimeOfDayInfoHacked.BootTime) &&
+        len >= offsetof(union buf, SysTimeOfDayInfoHacked.BootTimeBias) +
+                   sizeof(buf.SysTimeOfDayInfoHacked.BootTimeBias) &&
         buf.SysTimeOfDayInfoHacked.BootTime.QuadPart) {
-      bootid_collect(&bin, &buf.SysTimeOfDayInfoHacked.BootTime,
-                     sizeof(buf.SysTimeOfDayInfoHacked.BootTime));
-      got_boottime = true;
+      const uint64_t UnbiasedBootTime =
+          buf.SysTimeOfDayInfoHacked.BootTime.QuadPart -
+          buf.SysTimeOfDayInfoHacked.BootTimeBias;
+      if (UnbiasedBootTime) {
+        bootid_collect(&bin, &UnbiasedBootTime, sizeof(UnbiasedBootTime));
+        got_boottime = true;
+      }
     }
 
     if (!got_boottime) {
@@ -2413,7 +2516,7 @@ __cold int mdbx_get_sysraminfo(intptr_t *page_size, intptr_t *total_pages,
   if (unlikely(pagesize < MIN_PAGESIZE || !is_powerof2(pagesize)))
     return MDBX_INCOMPATIBLE;
 
-  __maybe_unused const int log2page = log2n_powerof2(pagesize);
+  MDBX_MAYBE_UNUSED const int log2page = log2n_powerof2(pagesize);
   assert(pagesize == (INT64_C(1) << log2page));
   (void)log2page;
 

src/osal.h

@@ -33,7 +33,7 @@
 #if defined(_WIN32) || defined(_WIN64)
 #if !defined(_CRT_SECURE_NO_WARNINGS)
 #define _CRT_SECURE_NO_WARNINGS
-#endif
+#endif /* _CRT_SECURE_NO_WARNINGS */
 #if !defined(_NO_CRT_STDIO_INLINE) && MDBX_BUILD_SHARED_LIBRARY &&             \
     !defined(xMDBX_TOOLS) && MDBX_WITHOUT_MSVC_CRT
 #define _NO_CRT_STDIO_INLINE
@@ -114,11 +114,9 @@
 #include <mach/mach_host.h>
 #include <mach/mach_port.h>
 #include <uuid/uuid.h>
-#undef P_DIRTY
 #endif
 
 #if defined(__linux__) || defined(__gnu_linux__)
-#include <linux/sysctl.h>
 #include <sched.h>
 #include <sys/sendfile.h>
 #include <sys/statfs.h>
@@ -440,7 +438,7 @@ typedef pthread_mutex_t mdbx_fastmutex_t;
 /* Get the size of a memory page for the system.
  * This is the basic size that the platform's memory manager uses, and is
  * fundamental to the use of memory-mapped files. */
-MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __inline size_t
+MDBX_MAYBE_UNUSED MDBX_NOTHROW_CONST_FUNCTION static __inline size_t
 mdbx_syspagesize(void) {
 #if defined(_WIN32) || defined(_WIN64)
   SYSTEM_INFO si;
@@ -460,8 +458,8 @@ typedef struct mdbx_mmap_param {
   mdbx_filehandle_t fd;
   size_t limit;   /* mapping length, but NOT a size of file nor DB */
   size_t current; /* mapped region size, i.e. the size of file and DB */
-#if defined(_WIN32) || defined(_WIN64)
   uint64_t filesize /* in-process cache of a file size */;
+#if defined(_WIN32) || defined(_WIN64)
   HANDLE section; /* memory-mapped section handle */
 #endif
 } mdbx_mmap_t;
@@ -481,9 +479,10 @@ typedef union MDBX_srwlock {
 } MDBX_srwlock;
 #endif /* Windows */
 
-#ifdef __cplusplus
-extern void mdbx_osal_jitter(bool tiny);
-#else
+#ifndef __cplusplus
+
+MDBX_MAYBE_UNUSED MDBX_INTERNAL_FUNC void mdbx_osal_jitter(bool tiny);
+MDBX_MAYBE_UNUSED static __inline void mdbx_jitter4testing(bool tiny);
 
 /*----------------------------------------------------------------------------*/
 /* Atomics */
@@ -527,7 +526,7 @@ extern void mdbx_osal_jitter(bool tiny);
 #include <sys/cachectl.h>
 #endif
 
-static __maybe_unused __inline void mdbx_compiler_barrier(void) {
+MDBX_MAYBE_UNUSED static __inline void mdbx_compiler_barrier(void) {
 #if defined(__clang__) || defined(__GNUC__)
   __asm__ __volatile__("" ::: "memory");
 #elif defined(_MSC_VER)
@@ -547,7 +546,7 @@ static __maybe_unused __inline void mdbx_compiler_barrier(void) {
 #endif
 }
 
-static __maybe_unused __inline void mdbx_memory_barrier(void) {
+MDBX_MAYBE_UNUSED static __inline void mdbx_memory_barrier(void) {
 #ifdef MDBX_HAVE_C11ATOMICS
   atomic_thread_fence(memory_order_seq_cst);
 #elif defined(__ATOMIC_SEQ_CST)
@@ -587,8 +586,8 @@ static __maybe_unused __inline void mdbx_memory_barrier(void) {
 #define mdbx_asprintf asprintf
 #define mdbx_vasprintf vasprintf
 #else
-MDBX_INTERNAL_FUNC MDBX_PRINTF_ARGS(2, 3) int __maybe_unused
-    mdbx_asprintf(char **strp, const char *fmt, ...);
+MDBX_MAYBE_UNUSED MDBX_INTERNAL_FUNC
+    MDBX_PRINTF_ARGS(2, 3) int mdbx_asprintf(char **strp, const char *fmt, ...);
 MDBX_INTERNAL_FUNC int mdbx_vasprintf(char **strp, const char *fmt, va_list ap);
 #endif
 
@@ -611,7 +610,7 @@ MDBX_INTERNAL_VAR bool mdbx_RunningOnWSL1 /* Windows Subsystem 1 for Linux */;
 LIBMDBX_API char *mdbx_strdup(const char *str);
 #endif
 
-static __maybe_unused __inline int mdbx_get_errno(void) {
+MDBX_MAYBE_UNUSED static __inline int mdbx_get_errno(void) {
 #if defined(_WIN32) || defined(_WIN64)
   DWORD rc = GetLastError();
 #else
@@ -695,8 +694,10 @@ MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,
                                  const size_t must, const size_t limit,
                                  const unsigned options);
 MDBX_INTERNAL_FUNC int mdbx_munmap(mdbx_mmap_t *map);
-MDBX_INTERNAL_FUNC int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t current,
-                                    size_t wanna, const bool may_move);
+#define MDBX_MRESIZE_MAY_MOVE 0x00000100
+#define MDBX_MRESIZE_MAY_UNMAP 0x00000200
+MDBX_INTERNAL_FUNC int mdbx_mresize(const int flags, mdbx_mmap_t *map,
+                                    size_t size, size_t limit);
 #if defined(_WIN32) || defined(_WIN64)
 typedef struct {
   unsigned limit, count;
@@ -713,7 +714,7 @@ MDBX_INTERNAL_FUNC int mdbx_msync(mdbx_mmap_t *map, size_t offset,
 MDBX_INTERNAL_FUNC int mdbx_check_fs_rdonly(mdbx_filehandle_t handle,
                                             const char *pathname, int err);
 
-static __maybe_unused __inline uint32_t mdbx_getpid(void) {
+MDBX_MAYBE_UNUSED static __inline uint32_t mdbx_getpid(void) {
   STATIC_ASSERT(sizeof(mdbx_pid_t) <= sizeof(uint32_t));
 #if defined(_WIN32) || defined(_WIN64)
   return GetCurrentProcessId();
@@ -722,7 +723,7 @@ static __maybe_unused __inline uint32_t mdbx_getpid(void) {
 #endif
 }
 
-static __maybe_unused __inline uintptr_t mdbx_thread_self(void) {
+MDBX_MAYBE_UNUSED static __inline uintptr_t mdbx_thread_self(void) {
   mdbx_tid_t thunk;
   STATIC_ASSERT(sizeof(uintptr_t) >= sizeof(thunk));
 #if defined(_WIN32) || defined(_WIN64)
@@ -733,7 +734,6 @@ static __maybe_unused __inline uintptr_t mdbx_thread_self(void) {
   return (uintptr_t)thunk;
 }
 
-MDBX_INTERNAL_FUNC void __maybe_unused mdbx_osal_jitter(bool tiny);
 MDBX_INTERNAL_FUNC uint64_t mdbx_osal_monotime(void);
 MDBX_INTERNAL_FUNC uint64_t
 mdbx_osal_16dot16_to_monotime(uint32_t seconds_16dot16);

src/version.c.in

@@ -8,7 +8,7 @@
 #error "API version mismatch! Had `git fetch --tags` done?"
 #endif
 
-static const char sourcery[] = STRINGIFY(MDBX_BUILD_SOURCERY);
+static const char sourcery[] = MDBX_STRINGIFY(MDBX_BUILD_SOURCERY);
 
 __dll_export
 #ifdef __attribute_used__

test/CMakeLists.txt

@@ -1,7 +1,7 @@
 enable_language(CXX)
 include(../cmake/compiler.cmake)
 
-add_executable(mdbx_test
+set(LIBMDBX_TEST_SOURCES
   base.h
   cases.cc
   chrono.cc
@@ -30,6 +30,12 @@ add_executable(mdbx_test
   nested.cc
   )
 
+if(NOT MDBX_BUILD_CXX)
+  list(APPEND LIBMDBX_TEST_SOURCES "${MDBX_SOURCE_DIR}/mdbx.c++" ../mdbx.h++)
+endif()
+
+add_executable(mdbx_test ${LIBMDBX_TEST_SOURCES})
+
 if(MDBX_CXX_STANDARD)
   set_target_properties(mdbx_test PROPERTIES
     CXX_STANDARD ${MDBX_CXX_STANDARD} CXX_STANDARD_REQUIRED ON)

test/base.h

@@ -23,7 +23,9 @@
 #define _WIN32_WINNT 0x0601 /* Windows 7 */
 #endif
 #ifdef _MSC_VER
+#ifndef _CRT_SECURE_NO_WARNINGS
 #define _CRT_SECURE_NO_WARNINGS
+#endif /* _CRT_SECURE_NO_WARNINGS */
 #pragma warning(push, 1)
 #pragma warning(disable : 4548) /* expression before comma has no effect;      \
                                    expected expression with side - effect */
@@ -86,7 +88,7 @@
 #define MDBX_INTERNAL_FUNC
 #define MDBX_INTERNAL_VAR extern
 #define xMDBX_TOOLS /* Avoid using internal mdbx_assert() */
-#include "../mdbx.h"
+#include "../mdbx.h++"
 #include "../src/defs.h"
 #include "../src/osal.h"
 

test/chrono.h

@@ -19,7 +19,7 @@
 
 namespace chrono {
 
-#pragma pack(push, 1)
+#pragma pack(push, 4)
 
 typedef union time {
   uint64_t fixedpoint;

test/config.cc

@@ -310,6 +310,7 @@ const struct option_verb mode_bits[] = {
     {"lifo", unsigned(MDBX_LIFORECLAIM)},
     {"perturb", unsigned(MDBX_PAGEPERTURB)},
     {"accede", unsigned(MDBX_ACCEDE)},
+    {"exclusive", unsigned(MDBX_EXCLUSIVE)},
     {nullptr, 0}};
 
 const struct option_verb table_bits[] = {

test/config.h

@@ -135,8 +135,6 @@ inline bool parse_option_intptr(int argc, char *const argv[], int &narg,
 
 //-----------------------------------------------------------------------------
 
-#pragma pack(push, 1)
-
 struct keygen_params_pod {
   /* Параметры генератора пар key-value. Также может быть полезным описание
    * алгоритма генерации в keygen.h
@@ -307,8 +305,6 @@ struct actor_config_pod {
         wait4id(wait4id) {}
 };
 
-#pragma pack(pop)
-
 extern const struct option_verb mode_bits[];
 extern const struct option_verb table_bits[];
 void dump(const char *title = "config-dump: ");

test/hill.cc

@@ -73,7 +73,12 @@ bool testcase_hill::run() {
   uint64_t committed_serial = serial_count;
   unsigned txn_nops = 0;
 
-  bool rc = false;
+  bool rc = speculum_verify();
+  if (!rc) {
+    log_notice("uphill: bailout before main loop");
+    goto bailout;
+  }
+
   while (should_continue()) {
     const keygen::serial_t a_serial = serial_count;
     if (unlikely(!keyvalue_maker.increment(serial_count, 1))) {

test/keygen.cc

@@ -243,23 +243,25 @@ void maker::seek2end(serial_t &serial) const {
   serial = actor_params::serial_mask(mapping.width) - 1;
 }
 
-bool maker::increment(serial_t &serial, int delta) const {
+bool maker::increment(serial_t &serial, int64_t delta) const {
   if (serial > actor_params::serial_mask(mapping.width)) {
     log_extra("keygen-increment: %" PRIu64 " > %" PRIu64 ", overflow", serial,
               actor_params::serial_mask(mapping.width));
     return false;
   }
 
-  serial_t target = serial + (int64_t)delta;
+  serial_t target = serial + delta;
   if (target > actor_params::serial_mask(mapping.width) ||
       ((delta > 0) ? target < serial : target > serial)) {
-    log_extra("keygen-increment: %" PRIu64 "%-d => %" PRIu64 ", overflow",
+    log_extra("keygen-increment: %" PRIu64 "%-" PRId64 " => %" PRIu64
+              ", overflow",
               serial, delta, target);
     return false;
   }
 
-  log_extra("keygen-increment: %" PRIu64 "%-d => %" PRIu64 ", continue", serial,
-            delta, target);
+  log_extra("keygen-increment: %" PRIu64 "%-" PRId64 " => %" PRIu64
+            ", continue",
+            serial, delta, target);
   serial = target;
   return true;
 }

test/keygen.h

@@ -130,8 +130,8 @@ public:
   bool is_unordered() const;
   void seek2end(serial_t &serial) const;
 
-  bool increment(serial_t &serial, int delta) const;
-  bool increment_key_part(serial_t &serial, int delta,
+  bool increment(serial_t &serial, int64_t delta) const;
+  bool increment_key_part(serial_t &serial, int64_t delta,
                           bool reset_value_part = true) const {
     if (reset_value_part) {
       serial_t value_part_bits = ((serial_t(1) << mapping.split) - 1);
@@ -139,7 +139,7 @@ public:
       if (delta >= 0)
         serial &= ~value_part_bits;
     }
-    return increment(serial, delta << mapping.split);
+    return increment(serial, int64_t(uint64_t(delta) << mapping.split));
   }
 };
 

test/long_stochastic.sh

@@ -1,36 +1,121 @@
 #!/usr/bin/env bash
-if ! which make cc c++ tee lz4 >/dev/null; then
-  echo "Please install the following prerequisites: make cc c++ tee lz4 banner" >&2
+if ! which make cc c++ tee >/dev/null; then
+  echo "Please install the following prerequisites: make cc c++ tee banner" >&2
   exit 1
 fi
 
+LIST=basic
+FROM=1
+UPTO=9999999
+MONITOR=
+LOOPS=
+SKIP_MAKE=no
 BANNER="$(which banner 2>/dev/null | echo echo)"
 UNAME="$(uname -s 2>/dev/null || echo Unknown)"
-set -euo pipefail
+DB_UPTO_MB=17408
 
-## NOTE: Valgrind could produce some false-positive warnings
-##       in multi-process environment with shared memory.
-##       For instance, when the process "A" explicitly marks a memory
-##       region as "undefined", the process "B" fill it,
-##       and after this process "A" read such region, etc.
-#VALGRIND="valgrind --trace-children=yes --log-file=valgrind-%p.log --leak-check=full --track-origins=yes --error-exitcode=42 --suppressions=test/valgrind_suppress.txt"
+while [ -n "$1" ]
+do
+  case "$1" in
+  --help)
+    echo "--multi                Engage multi-process test scenario (default)"
+    echo "--single               Execute series of single-process tests (for QEMU, etc)"
+    echo "--with-valgrind        Run tests under Valgrind's memcheck tool"
+    echo "--skip-make            Don't (re)build libmdbx and test's executable"
+    echo "--from NN              Start iterating from the NN ops per test case"
+    echo "--upto NN              Don't run tests with more than NN ops per test case"
+    echo "--loops NN             Stop after the NN loops"
+    echo "--dir PATH             Specifies directory for test DB and other files (it will be cleared)"
+    echo "--db-upto-mb NN        Limits upper size of test DB to the NN megabytes"
+    echo "--help                 Print this usage help and exit"
+    exit -2
+  ;;
+  --multi)
+    LIST=basic
+  ;;
+  --single)
+    LIST="--nested --hill --append --ttl --copy"
+  ;;
+  --with-valgrind)
+    echo " NOTE: Valgrind could produce some false-positive warnings"
+    echo "       in multi-process environment with shared memory."
+    echo "       For instance, when the process 'A' explicitly marks a memory"
+    echo "       region as 'undefined', the process 'B' fill it,"
+    echo "       and after this process 'A' read such region, etc."
+    MONITOR="valgrind --trace-children=yes --log-file=valgrind-%p.log --leak-check=full --track-origins=yes --error-exitcode=42 --suppressions=test/valgrind_suppress.txt"
+    rm -f valgrind-*.log
+  ;;
+  --skip-make)
+    SKIP_MAKE=yes
+  ;;
+  --from)
+    FROM=$(($2))
+    if [ -z "$FROM" -o "$FROM" -lt 1 ]; then
+      echo "Invalid value '$FROM' for --from option"
+      exit -2
+    fi
+    shift
+  ;;
+  --upto)
+    UPTO=$(($2))
+    if [ -z "$UPTO" -o "$UPTO" -lt 1 ]; then
+      echo "Invalid value '$UPTO' for --upto option"
+      exit -2
+    fi
+    shift
+  ;;
+  --loops)
+    LOOPS=$(($2))
+    if [ -z "$LOOPS" -o "$LOOPS" -lt 1 -o "$LOOPS" -gt 99 ]; then
+      echo "Invalid value '$LOOPS' for --loops option"
+      exit -2
+    fi
+    shift
+  ;;
+  --dir)
+    TESTDB_DIR="$2"
+    if [ -z "$TESTDB_DIR" ]; then
+      echo "Invalid value '$TESTDB_DIR' for --dir option"
+      exit -2
+    fi
+    shift
+  ;;
+  --db-upto-mb)
+    DB_UPTO_MB=$(($2))
+    if [ -z "$DB_UPTO_MB" -o "$DB_UPTO_MB" -lt 1 -o "$DB_UPTO_MB" -gt 4194304 ]; then
+      echo "Invalid value '$DB_UPTO_MB' for --db-upto-mb option"
+      exit -2
+    fi
+    shift
+  ;;
+  *)
+    echo "Unknown option '$1'"
+    exit -2
+  ;;
+  esac
+ shift
+done
+
+set -euo pipefail
+if [ -z "$MONITOR" ]; then
+  if which time >/dev/null 2>/dev/null; then
+    MONITOR=$(which time)
+    if $MONITOR -o /dev/stdout true >/dev/null 2>/dev/null; then
+      MONITOR="$MONITOR -o /dev/stdout"
+    fi
+  fi
+  export MALLOC_CHECK_=7 MALLOC_PERTURB_=42
+fi
 
 ###############################################################################
 # 1. clean data from prev runs and examine available RAM
 
-if [[ -v VALGRIND && ! -z "$VALGRIND" ]]; then
-  rm -f valgrind-*.log
-else
-  VALGRIND=time
-  export MALLOC_CHECK_=7 MALLOC_PERTURB_=42
-fi
-
 WANNA_MOUNT=0
 case ${UNAME} in
   Linux)
     MAKE=make
-    if [[ ! -v TESTDB_DIR || -z "$TESTDB_DIR" ]]; then
-      for old_test_dir in $(ls -d /dev/shm/mdbx-test.[0-9]*); do
+    if [ -z "${TESTDB_DIR:-}" ]; then
+      for old_test_dir in $(ls -d /dev/shm/mdbx-test.[0-9]* 2>/dev/null); do
         rm -rf $old_test_dir
       done
       TESTDB_DIR="/dev/shm/mdbx-test.$$"
@@ -46,8 +131,8 @@ case ${UNAME} in
 
   FreeBSD)
     MAKE=gmake
-    if [[ ! -v TESTDB_DIR || -z "$TESTDB_DIR" ]]; then
-      for old_test_dir in $(ls -d /tmp/mdbx-test.[0-9]*); do
+    if [ -z "${TESTDB_DIR:-}" ]; then
+      for old_test_dir in $(ls -d /tmp/mdbx-test.[0-9]* 2>/dev/null); do
         umount $old_test_dir && rm -r $old_test_dir
       done
       TESTDB_DIR="/tmp/mdbx-test.$$"
@@ -56,14 +141,13 @@ case ${UNAME} in
     else
       mkdir -p $TESTDB_DIR && rm -f $TESTDB_DIR/*
     fi
-
     ram_avail_mb=$(($(LC_ALL=C vmstat -s | grep -ie '[0-9] pages free$' | cut -d p -f 1) * ($(LC_ALL=C vmstat -s | grep -ie '[0-9] bytes per page$' | cut -d b -f 1) / 1024) / 1024))
   ;;
 
   Darwin)
     MAKE=make
-    if [[ ! -v TESTDB_DIR || -z "$TESTDB_DIR" ]]; then
-      for vol in $(ls -d /Volumes/mdx[0-9]*[0-9]tst); do
+    if [ -z "${TESTDB_DIR:-}" ]; then
+      for vol in $(ls -d /Volumes/mdx[0-9]*[0-9]tst 2>/dev/null); do
         disk=$(mount | grep $vol | cut -d ' ' -f 1)
         echo "umount: volume $vol disk $disk"
         hdiutil unmount $vol -force
@@ -74,12 +158,10 @@ case ${UNAME} in
     else
       mkdir -p $TESTDB_DIR && rm -f $TESTDB_DIR/*
     fi
-
     pagesize=$(($(LC_ALL=C vm_stat | grep -o 'page size of [0-9]\+ bytes' | cut -d' ' -f 4) / 1024))
     freepages=$(LC_ALL=C vm_stat | grep '^Pages free:' | grep -o '[0-9]\+\.$' | cut -d'.' -f 1)
     ram_avail_mb=$((pagesize * freepages / 1024))
     echo "pagesize ${pagesize}K, freepages ${freepages}, ram_avail_mb ${ram_avail_mb}"
-
   ;;
 
   *)
@@ -88,6 +170,8 @@ case ${UNAME} in
   ;;
 esac
 
+rm -f ${TESTDB_DIR}/*
+
 ###############################################################################
 # 2. estimate reasonable RAM space for test-db
 
@@ -117,8 +201,8 @@ fi
 # system immediately, as well some space is required for logs.
 #
 db_size_mb=$(((ram_avail_mb - ram_reserve4logs_mb) / 4))
-if [ $db_size_mb -gt 17408 ]; then
-  db_size_mb=17408
+if [ $db_size_mb -gt $DB_UPTO_MB ]; then
+  db_size_mb=$DB_UPTO_MB
 fi
 echo "=== use ${db_size_mb}M for DB"
 
@@ -150,48 +234,80 @@ case ${UNAME} in
 esac
 
 ###############################################################################
-# 4. Run basic test, i.e. `make check`
+# 4. build the test executables
 
-${MAKE} -j2 all mdbx_test
-#${MAKE} TEST_DB=${TESTDB_DIR}/smoke.db TEST_LOG=${TESTDB_DIR}/smoke.log check
-rm -f ${TESTDB_DIR}/*
+if [ "$SKIP_MAKE" != "yes" ]; then
+  ${MAKE} -j$(which nproc  >/dev/null 2>/dev/null && nproc || echo 2) build-test
+fi
 
 ###############################################################################
 # 5. run stochastic iterations
 
-function join { local IFS="$1"; shift; echo "$*"; }
-function bit2option { local -n arr=$1; (( ($2&(1<<$3)) != 0 )) && echo -n '+' || echo -n '-'; echo "${arr[$3]}"; }
+if which lz4 >/dev/null; then
+  function logger {
+    lz4 > ${TESTDB_DIR}/long.log.lz4
+  }
+elif which gzip >/dev/null; then
+  function logger {
+    gzip > ${TESTDB_DIR}/long.log.gz
+  }
+else
+  function logger {
+    cat > ${TESTDB_DIR}/long.log
+  }
+fi
 
 syncmodes=("" ,+nosync-safe ,+nosync-utterly)
-
 options=(writemap coalesce lifo notls perturb)
 
-function bits2list {
-  local -n arr=$1
+function join { local IFS="$1"; shift; echo "$*"; }
+
+function bits2options {
+  local bits=$1
   local i
   local list=()
-  for ((i=0; i<${#arr[@]}; ++i)) do
-    list[$i]=$(bit2option $1 $2 $i)
+  for ((i = 0; i < ${#options[@]}; ++i)); do
+    list[$i]=$( (( (bits & (1 << i)) != 0 )) && echo -n '+' || echo -n '-'; echo ${options[$i]})
   done
-  join , "${list[@]}"
+  join , ${list[@]}
+}
+
+function failed {
+  echo "FAILED" >&2
+  exit 1
+}
+
+function check_deep {
+  if [ "$case" = "basic" -o "$case" = "--hill" ]; then
+    tee >(logger) | grep -e reach -e achieve
+  else
+    logger
+  fi
 }
 
 function probe {
   echo "----------------------------------------------- $(date)"
-  echo "${caption}: $*"
-  rm -f ${TESTDB_DIR}/* \
-    && ${VALGRIND} ./mdbx_test ${speculum} --random-writemap=no --ignore-dbfull --repeat=11 --pathname=${TESTDB_DIR}/long.db --cleanup-after=no "$@" \
-      | tee >(lz4 > ${TESTDB_DIR}/long.log.lz4) | grep -e reach -e achieve \
-    && ${VALGRIND} ./mdbx_chk ${TESTDB_DIR}/long.db | tee ${TESTDB_DIR}/long-chk.log \
-    && ([ ! -e ${TESTDB_DIR}/long.db-copy ] || ${VALGRIND} ./mdbx_chk ${TESTDB_DIR}/long.db-copy | tee ${TESTDB_DIR}/long-chk-copy.log) \
-    || (echo "FAILED"; exit 1)
+  echo "${caption}"
+  rm -f ${TESTDB_DIR}/* || failed
+  for case in $LIST
+  do
+    echo "Run ./mdbx_test ${speculum} --random-writemap=no --ignore-dbfull --repeat=11 --pathname=${TESTDB_DIR}/long.db --cleanup-after=no $@ $case"
+    ${MONITOR} ./mdbx_test ${speculum} --random-writemap=no --ignore-dbfull --repeat=11 --pathname=${TESTDB_DIR}/long.db --cleanup-after=no "$@" $case | check_deep \
+      && ${MONITOR} ./mdbx_chk ${TESTDB_DIR}/long.db | tee ${TESTDB_DIR}/long-chk.log \
+      && ([ ! -e ${TESTDB_DIR}/long.db-copy ] || ${MONITOR} ./mdbx_chk ${TESTDB_DIR}/long.db-copy | tee ${TESTDB_DIR}/long-chk-copy.log) \
+      || failed
+   done
 }
 
 #------------------------------------------------------------------------------
 
 count=0
+loop=0
 cases='?'
 for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10000000 33333333 100000000 333333333 1000000000; do
+  if [ $nops -lt $FROM ]; then continue; fi
+  if [ $nops -gt $UPTO ]; then echo "The '--upto $UPTO' limit reached"; break; fi
+  if [ -n "$LOOPS" ] && [ $loop -ge "$LOOPS" ]; then echo "The '--loops $LOOPS' limit reached"; break; fi
   echo "======================================================================="
   wbatch=$((nops / 7 + 1))
   speculum=$([ $nops -le 1000 ] && echo '--speculum' || true)
@@ -204,68 +320,70 @@ for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10
 
       split=30
       caption="Probe #$((++count)) int-key,with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
 
       split=24
       caption="Probe #$((++count)) int-key,with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
 
       split=16
       caption="Probe #$((++count)) int-key,w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) int-key,with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
 
       split=4
       caption="Probe #$((++count)) int-key,w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
       caption="Probe #$((++count)) w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
-        --pagesize=min --size-upper=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
-        --nops=$nops --batch.write=$wbatch --mode=$(bits2list options $bits)${syncmodes[count%3]} \
-        --keygen.seed=${seed} basic
+        --pagesize=min --size-upper-upto=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
     done # options
+    loop=$((loop + 1))
+    if [ -n "$LOOPS" ] && [ $loop -ge "$LOOPS" ]; then break; fi
     cases="${subcase}"
     wbatch=$(((wbatch > 7) ? wbatch / 7 : 1))
     if [ $wbatch -eq 1 -o $((nops / wbatch)) -gt 1000 ]; then break; fi

test/main.cc

@@ -92,6 +92,8 @@ MDBX_NORETURN void usage(void) {
       "  --mode={[+-]FLAG}[,[+-]FLAG]...\n"
       "    nosubdir       == MDBX_NOSUBDIR\n"
       "    rdonly         == MDBX_RDONLY\n"
+      "    exclusive      == MDBX_EXCLUSIVE\n"
+      "    accede         == MDBX_ACCEDE\n"
       "    nometasync     == MDBX_NOMETASYNC\n"
       "    lifo           == MDBX_LIFORECLAIM\n"
       "    coalesce       == MDBX_COALESCE\n"
@@ -222,6 +224,43 @@ void cleanup() {
   log_trace("<< cleanup");
 }
 
+static void fixup4qemu(actor_params &params) {
+#ifdef MDBX_SAFE4QEMU
+#if MDBX_WORDBITS == 32
+  intptr_t safe4qemu_limit = size_t(512) << 20 /* 512 megabytes */;
+#if defined(__SANITIZE_ADDRESS__)
+  safe4qemu_limit >>= 1;
+#else
+  if (RUNNING_ON_VALGRIND)
+    safe4qemu_limit >>= 1;
+#endif /* __SANITIZE_ADDRESS__ */
+
+  if (params.size_lower > safe4qemu_limit ||
+      params.size_now > safe4qemu_limit ||
+      params.size_upper > safe4qemu_limit) {
+    params.size_upper = std::min(params.size_upper, safe4qemu_limit);
+    params.size_now = std::min(params.size_now, params.size_upper);
+    params.size_lower = std::min(params.size_lower, params.size_now);
+    log_notice("workaround: for conformance 32-bit build with "
+               "QEMU/ASAN/Valgrind database size reduced to %zu megabytes",
+               safe4qemu_limit >> 20);
+  }
+#endif /* MDBX_WORDBITS == 32 */
+
+#if defined(__alpha__) || defined(__alpha) || defined(__sparc__) ||            \
+    defined(__sparc) || defined(__sparc64__) || defined(__sparc64)
+  if (params.size_lower != params.size_upper) {
+    log_notice(
+        "workaround: for conformance Alpha/Sparc build with QEMU/ASAN/Valgrind "
+        "enforce fixed database size %zu megabytes",
+        params.size_upper >> 20);
+    params.size_lower = params.size_now = params.size_upper;
+  }
+#endif /* Alpha || Sparc */
+#endif /* MDBX_SAFE4QEMU */
+  (void)params;
+}
+
 int main(int argc, char *const argv[]) {
 
 #ifdef _DEBUG
@@ -254,6 +293,7 @@ int main(int argc, char *const argv[]) {
     const char *value = nullptr;
 
     if (config::parse_option(argc, argv, narg, "case", &value)) {
+      fixup4qemu(params);
       testcase_setup(value, params, last_space_id);
       continue;
     }
@@ -327,6 +367,15 @@ int main(int argc, char *const argv[]) {
                                     mdbx_limits_dbsize_min(params.pagesize),
                                     mdbx_limits_dbsize_max(params.pagesize)))
       continue;
+    int64_t i64 = params.size_upper;
+    if (config::parse_option(argc, argv, narg, "size-upper-upto", i64,
+                             int64_t(mdbx_limits_dbsize_min(params.pagesize)),
+                             INT64_MAX, -1)) {
+      if (i64 > mdbx_limits_dbsize_max(params.pagesize))
+        i64 = mdbx_limits_dbsize_max(params.pagesize);
+      params.size_upper = intptr_t(i64);
+      continue;
+    }
     if (config::parse_option_intptr(argc, argv, narg, "size-upper",
                                     params.size_upper,
                                     mdbx_limits_dbsize_min(params.pagesize),
@@ -477,38 +526,47 @@ int main(int argc, char *const argv[]) {
       continue;
     }
     if (config::parse_option(argc, argv, narg, "hill", &value, "auto")) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_hill, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "jitter", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_jitter, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "dead.reader", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_deadread, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "dead.writer", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_deadwrite, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "try", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_try, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "copy", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_copy, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "append", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_append, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "ttl", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_ttl, value, params);
       continue;
     }
     if (config::parse_option(argc, argv, narg, "nested", nullptr)) {
+      fixup4qemu(params);
       configure_actor(last_space_id, ac_nested, value, params);
       continue;
     }
@@ -522,9 +580,10 @@ int main(int argc, char *const argv[]) {
                              global::config::console_mode))
       continue;
 
-    if (*argv[narg] != '-')
+    if (*argv[narg] != '-') {
+      fixup4qemu(params);
       testcase_setup(argv[narg], params, last_space_id);
-    else
+    } else
       failure("Unknown option '%s'. Try --help\n", argv[narg]);
   }
 
@@ -550,10 +609,6 @@ int main(int argc, char *const argv[]) {
   if (global::config::cleanup_before)
     cleanup();
 
-  log_trace(">> probe entropy_ticks()");
-  entropy_ticks();
-  log_trace("<< probe entropy_ticks()");
-
   if (global::actors.size() == 1) {
     logging::setup("main");
     global::singlemode = true;

test/nested.cc

@@ -110,16 +110,26 @@ bool testcase_nested::teardown() {
 }
 
 void testcase_nested::push_txn() {
-  MDBX_txn *txn;
+  MDBX_txn *nested_txn;
   MDBX_txn_flags_t flags = MDBX_txn_flags_t(
       prng32() & uint32_t(MDBX_TXN_NOSYNC | MDBX_TXN_NOMETASYNC));
-  int err = mdbx_txn_begin(db_guard.get(), txn_guard.get(), flags, &txn);
+  int err = mdbx_txn_begin(db_guard.get(), txn_guard.get(), flags, &nested_txn);
   if (unlikely(err != MDBX_SUCCESS))
     failure_perror("mdbx_txn_begin(nested)", err);
-  stack.emplace(scoped_txn_guard(txn), serial, fifo, speculum);
-  std::swap(txn_guard, std::get<0>(stack.top()));
+  /* CLANG/LLVM C++ library could stupidly copy std::set<> item-by-item,
+   * i.e. with insertion(s) & comparison(s), which will cause null dereference
+   * during call mdbx_cmp() with zero txn. So it is the workaround for this:
+   *  - explicitly set txn_guard with the new nested txn;
+   *  - explicitly copy the `speculum` (an instance of std::set<>). */
+  scoped_txn_guard nested_txn_guard(nested_txn);
+  txn_guard.swap(nested_txn_guard);
+  SET speculum_snapshot(speculum);
+  stack.emplace(std::move(nested_txn_guard), serial, fifo,
+                std::move(speculum_snapshot));
   log_verbose("begin level#%zu txn #%" PRIu64 ", flags 0x%x, serial %" PRIu64,
-              stack.size(), mdbx_txn_id(txn), flags, serial);
+              stack.size(), mdbx_txn_id(nested_txn), flags, serial);
+  if (!dbi && stack.size() == 1)
+    dbi = db_table_open(true);
 }
 
 bool testcase_nested::pop_txn(bool abort) {
@@ -131,6 +141,9 @@ bool testcase_nested::pop_txn(bool abort) {
     log_verbose(
         "abort level#%zu txn #%" PRIu64 ", undo serial %" PRIu64 " <- %" PRIu64,
         stack.size(), mdbx_txn_id(txn), serial, std::get<1>(stack.top()));
+    if (dbi > 0 && stack.size() == 1 &&
+        is_handle_created_in_current_txn(dbi, txn))
+      dbi = 0;
     int err = mdbx_txn_abort(txn);
     if (unlikely(err != MDBX_SUCCESS))
       failure_perror("mdbx_txn_abort()", err);
@@ -192,7 +205,7 @@ bool testcase_nested::trim_tail(unsigned window_width) {
     while (fifo.size() > window_width) {
       uint64_t tail_serial = fifo.back().first;
       const unsigned tail_count = fifo.back().second;
-      log_verbose("nested: pop-tail (serial %" PRIu64 ", count %u)",
+      log_verbose("nested: trim-tail (serial %" PRIu64 ", count %u)",
                   tail_serial, tail_count);
       fifo.pop_back();
       for (unsigned n = 0; n < tail_count; ++n) {

test/osal-unix.cc

@@ -45,11 +45,11 @@
 
 #if __cplusplus >= 201103L
 #include <atomic>
-static __inline __maybe_unused int atomic_decrement(std::atomic_int *p) {
+MDBX_MAYBE_UNUSED static __inline int atomic_decrement(std::atomic_int *p) {
   return std::atomic_fetch_sub(p, 1) - 1;
 }
 #else
-static __inline __maybe_unused int atomic_decrement(volatile int *p) {
+MDBX_MAYBE_UNUSED static __inline int atomic_decrement(volatile int *p) {
 #if defined(__GNUC__) || defined(__clang__)
   return __sync_sub_and_fetch(p, 1);
 #elif defined(_MSC_VER)

test/stochastic_small.sh

@@ -0,0 +1,365 @@
+#!/usr/bin/env bash
+if ! which make cc c++ tee >/dev/null; then
+  echo "Please install the following prerequisites: make cc c++ tee banner" >&2
+  exit 1
+fi
+
+LIST=--hill
+FROM=1
+UPTO=9999
+MONITOR=
+LOOPS=
+SKIP_MAKE=no
+BANNER="$(which banner 2>/dev/null | echo echo)"
+UNAME="$(uname -s 2>/dev/null || echo Unknown)"
+DB_UPTO_MB=17408
+
+while [ -n "$1" ]
+do
+  case "$1" in
+  --help)
+    echo "--multi                Engage multi-process test scenario (default)"
+    echo "--single               Execute series of single-process tests (for QEMU, etc)"
+    echo "--with-valgrind        Run tests under Valgrind's memcheck tool"
+    echo "--skip-make            Don't (re)build libmdbx and test's executable"
+    echo "--from NN              Start iterating from the NN ops per test case"
+    echo "--upto NN              Don't run tests with more than NN ops per test case"
+    echo "--loops NN             Stop after the NN loops"
+    echo "--dir PATH             Specifies directory for test DB and other files (it will be cleared)"
+    echo "--db-upto-mb NN        Limits upper size of test DB to the NN megabytes"
+    echo "--help                 Print this usage help and exit"
+    exit -2
+  ;;
+  --multi)
+    LIST=basic
+  ;;
+  --single)
+    LIST="--nested --hill --append --ttl --copy"
+  ;;
+  --with-valgrind)
+    echo " NOTE: Valgrind could produce some false-positive warnings"
+    echo "       in multi-process environment with shared memory."
+    echo "       For instance, when the process 'A' explicitly marks a memory"
+    echo "       region as 'undefined', the process 'B' fill it,"
+    echo "       and after this process 'A' read such region, etc."
+    MONITOR="valgrind --trace-children=yes --log-file=valgrind-%p.log --leak-check=full --track-origins=yes --error-exitcode=42 --suppressions=test/valgrind_suppress.txt"
+    rm -f valgrind-*.log
+  ;;
+  --skip-make)
+    SKIP_MAKE=yes
+  ;;
+  --from)
+    FROM=$(($2))
+    if [ -z "$FROM" -o "$FROM" -lt 1 ]; then
+      echo "Invalid value '$FROM' for --from option"
+      exit -2
+    fi
+    shift
+  ;;
+  --upto)
+    UPTO=$(($2))
+    if [ -z "$UPTO" -o "$UPTO" -lt 1 ]; then
+      echo "Invalid value '$UPTO' for --upto option"
+      exit -2
+    fi
+    shift
+  ;;
+  --loops)
+    LOOPS=$(($2))
+    if [ -z "$LOOPS" -o "$LOOPS" -lt 1 -o "$LOOPS" -gt 99 ]; then
+      echo "Invalid value '$LOOPS' for --loops option"
+      exit -2
+    fi
+    shift
+  ;;
+  --dir)
+    TESTDB_DIR="$2"
+    if [ -z "$TESTDB_DIR" ]; then
+      echo "Invalid value '$TESTDB_DIR' for --dir option"
+      exit -2
+    fi
+    shift
+  ;;
+  --db-upto-mb)
+    DB_UPTO_MB=$(($2))
+    if [ -z "$DB_UPTO_MB" -o "$DB_UPTO_MB" -lt 1 -o "$DB_UPTO_MB" -gt 4194304 ]; then
+      echo "Invalid value '$DB_UPTO_MB' for --db-upto-mb option"
+      exit -2
+    fi
+    shift
+  ;;
+  *)
+    echo "Unknown option '$1'"
+    exit -2
+  ;;
+  esac
+ shift
+done
+
+set -euo pipefail
+if [ -z "$MONITOR" ]; then
+  if which time >/dev/null 2>/dev/null; then
+    MONITOR=$(which time)
+    if $MONITOR -o /dev/stdout true >/dev/null 2>/dev/null; then
+      MONITOR="$MONITOR -o /dev/stdout"
+    fi
+  fi
+  export MALLOC_CHECK_=7 MALLOC_PERTURB_=42
+fi
+
+###############################################################################
+# 1. clean data from prev runs and examine available RAM
+
+WANNA_MOUNT=0
+case ${UNAME} in
+  Linux)
+    MAKE=make
+    if [ -z "${TESTDB_DIR:-}" ]; then
+      for old_test_dir in $(ls -d /dev/shm/mdbx-test.[0-9]* 2>/dev/null); do
+        rm -rf $old_test_dir
+      done
+      TESTDB_DIR="/dev/shm/mdbx-test.$$"
+    fi
+    mkdir -p $TESTDB_DIR && rm -f $TESTDB_DIR/*
+
+    if LC_ALL=C free | grep -q -i available; then
+      ram_avail_mb=$(($(LC_ALL=C free | grep -i Mem: | tr -s [:blank:] ' ' | cut -d ' ' -f 7) / 1024))
+    else
+      ram_avail_mb=$(($(LC_ALL=C free | grep -i Mem: | tr -s [:blank:] ' ' | cut -d ' ' -f 4) / 1024))
+    fi
+  ;;
+
+  FreeBSD)
+    MAKE=gmake
+    if [ -z "${TESTDB_DIR:-}" ]; then
+      for old_test_dir in $(ls -d /tmp/mdbx-test.[0-9]* 2>/dev/null); do
+        umount $old_test_dir && rm -r $old_test_dir
+      done
+      TESTDB_DIR="/tmp/mdbx-test.$$"
+      rm -rf $TESTDB_DIR && mkdir -p $TESTDB_DIR
+      WANNA_MOUNT=1
+    else
+      mkdir -p $TESTDB_DIR && rm -f $TESTDB_DIR/*
+    fi
+    ram_avail_mb=$(($(LC_ALL=C vmstat -s | grep -ie '[0-9] pages free$' | cut -d p -f 1) * ($(LC_ALL=C vmstat -s | grep -ie '[0-9] bytes per page$' | cut -d b -f 1) / 1024) / 1024))
+  ;;
+
+  Darwin)
+    MAKE=make
+    if [ -z "${TESTDB_DIR:-}" ]; then
+      for vol in $(ls -d /Volumes/mdx[0-9]*[0-9]tst 2>/dev/null); do
+        disk=$(mount | grep $vol | cut -d ' ' -f 1)
+        echo "umount: volume $vol disk $disk"
+        hdiutil unmount $vol -force
+        hdiutil detach $disk
+      done
+      TESTDB_DIR="/Volumes/mdx$$tst"
+      WANNA_MOUNT=1
+    else
+      mkdir -p $TESTDB_DIR && rm -f $TESTDB_DIR/*
+    fi
+    pagesize=$(($(LC_ALL=C vm_stat | grep -o 'page size of [0-9]\+ bytes' | cut -d' ' -f 4) / 1024))
+    freepages=$(LC_ALL=C vm_stat | grep '^Pages free:' | grep -o '[0-9]\+\.$' | cut -d'.' -f 1)
+    ram_avail_mb=$((pagesize * freepages / 1024))
+    echo "pagesize ${pagesize}K, freepages ${freepages}, ram_avail_mb ${ram_avail_mb}"
+  ;;
+
+  *)
+    echo "FIXME: ${UNAME} not supported by this script"
+    exit 2
+  ;;
+esac
+
+rm -f ${TESTDB_DIR}/*
+
+###############################################################################
+# 2. estimate reasonable RAM space for test-db
+
+echo "=== ${ram_avail_mb}M RAM available"
+ram_reserve4logs_mb=1234
+if [ $ram_avail_mb -lt $ram_reserve4logs_mb ]; then
+  echo "=== At least ${ram_reserve4logs_mb}Mb RAM required"
+  exit 3
+fi
+
+#
+# В режимах отличных от MDBX_WRITEMAP изменения до записи в файл
+# будут накапливаться в памяти, что может потребовать свободной
+# памяти размером с БД. Кроме этого, в тест входит сценарий
+# создания копия БД на ходу. Поэтому БД не может быть больше 1/3
+# от доступной памяти. Однако, следует учесть что malloc() будет
+# не сразу возвращать выделенную память системе, а также
+# предусмотреть места для логов.
+#
+# In non-MDBX_WRITEMAP modes, updates (dirty pages) will
+# accumulate in memory before writing to the disk, which may
+# require a free memory up to the size of a whole database. In
+# addition, the test includes a script create a copy of the
+# database on the go. Therefore, the database cannot be more 1/3
+# of available memory. Moreover, should be taken into account
+# that malloc() will not return the allocated memory to the
+# system immediately, as well some space is required for logs.
+#
+db_size_mb=$(((ram_avail_mb - ram_reserve4logs_mb) / 4))
+if [ $db_size_mb -gt $DB_UPTO_MB ]; then
+  db_size_mb=$DB_UPTO_MB
+fi
+echo "=== use ${db_size_mb}M for DB"
+
+###############################################################################
+# 3. Create test-directory in ramfs/tmpfs, i.e. create/format/mount if required
+case ${UNAME} in
+  Linux)
+  ;;
+
+  FreeBSD)
+    if [[ WANNA_MOUNT ]]; then
+      mount -t tmpfs tmpfs $TESTDB_DIR
+    fi
+  ;;
+
+  Darwin)
+    if [[ WANNA_MOUNT ]]; then
+      ramdisk_size_mb=$((42 + db_size_mb * 2 + ram_reserve4logs_mb))
+      number_of_sectors=$((ramdisk_size_mb * 2048))
+      ramdev=$(hdiutil attach -nomount ram://${number_of_sectors})
+      diskutil erasevolume ExFAT "mdx$$tst" ${ramdev}
+    fi
+  ;;
+
+  *)
+    echo "FIXME: ${UNAME} not supported by this script"
+    exit 2
+  ;;
+esac
+
+###############################################################################
+# 4. build the test executables
+
+if [ "$SKIP_MAKE" != "yes" ]; then
+  ${MAKE} -j$(which nproc  >/dev/null 2>/dev/null && nproc || echo 2) build-test
+fi
+
+###############################################################################
+# 5. run stochastic iterations
+
+if which lz4 >/dev/null; then
+  function logger {
+    lz4 > ${TESTDB_DIR}/long.log.lz4
+  }
+elif which gzip >/dev/null; then
+  function logger {
+    gzip > ${TESTDB_DIR}/long.log.gz
+  }
+else
+  function logger {
+    cat > ${TESTDB_DIR}/long.log
+  }
+fi
+
+syncmodes=("" ,+nosync-safe ,+nosync-utterly)
+options=(writemap coalesce lifo notls perturb)
+
+function join { local IFS="$1"; shift; echo "$*"; }
+
+function bits2options {
+  local bits=$1
+  local i
+  local list=()
+  for ((i = 0; i < ${#options[@]}; ++i)); do
+    list[$i]=$( (( (bits & (1 << i)) != 0 )) && echo -n '+' || echo -n '-'; echo ${options[$i]})
+  done
+  join , ${list[@]}
+}
+
+function failed {
+  echo "FAILED" >&2
+  exit 1
+}
+
+function check_deep {
+  if [ "$case" = "basic" -o "$case" = "--hill" ]; then
+    tee >(logger) | grep -e reach -e achieve
+  else
+    logger
+  fi
+}
+
+function probe {
+  echo "----------------------------------------------- $(date)"
+  echo "${caption}"
+  rm -f ${TESTDB_DIR}/* || failed
+  for case in $LIST
+  do
+    echo "Run ./mdbx_test ${speculum} --random-writemap=no --ignore-dbfull --repeat=1 --pathname=${TESTDB_DIR}/long.db --cleanup-after=no $@ $case"
+    ${MONITOR} ./mdbx_test ${speculum} --random-writemap=no --ignore-dbfull --repeat=1 --pathname=${TESTDB_DIR}/long.db --cleanup-before=yes --cleanup-after=no "$@" $case | check_deep \
+      && ${MONITOR} ./mdbx_chk ${TESTDB_DIR}/long.db | tee ${TESTDB_DIR}/long-chk.log \
+      && ([ ! -e ${TESTDB_DIR}/long.db-copy ] || ${MONITOR} ./mdbx_chk ${TESTDB_DIR}/long.db-copy | tee ${TESTDB_DIR}/long-chk-copy.log) \
+      || failed
+   done
+}
+
+#------------------------------------------------------------------------------
+
+count=0
+loop=0
+cases='?'
+for ((wbatch=FROM; wbatch<=UPTO; ++wbatch)); do
+  if [ -n "$LOOPS" ] && [ $loop -ge "$LOOPS" ]; then echo "The '--loops $LOOPS' limit reached"; break; fi
+  echo "======================================================================="
+  speculum=$([ $wbatch -le 1000 ] && echo '--speculum' || true)
+  nops=$((wbatch/7 + 1))
+  for ((rep=1; rep < 11; ++rep)); do
+    echo "======================================================================="
+    ${BANNER} "$nops / $wbatch, repeat $rep"
+    subcase=0
+    for ((bits=2**${#options[@]}; --bits >= 0; )); do
+      seed=$(($(date +%s) + RANDOM))
+
+      split=30
+      caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+
+      split=24
+      caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+
+      split=16
+      caption="Probe #$((++count)) int-key,w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=+key.integer,-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+      caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+      caption="Probe #$((++count)) w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+
+      split=4
+      caption="Probe #$((++count)) int-key,w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=+key.integer,-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+      caption="Probe #$((++count)) int-key,int-data, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.integer --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+      caption="Probe #$((++count)) w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --pagesize=4K --size-upper-upto=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%3]} \
+        --keygen.seed=${seed}
+    done # options
+    cases="${subcase}"
+  done # repeats
+  loop=$((loop + 1))
+  if [ -n "$LOOPS" ] && [ $loop -ge "$LOOPS" ]; then break; fi
+done # wbatch
+
+echo "=== ALL DONE ====================== $(date)"

test/test.cc

@@ -197,6 +197,18 @@ int testcase::breakable_commit() {
   log_trace(">> txn_commit");
   assert(txn_guard);
 
+  /* CLANG/LLVM C++ library could stupidly copy std::set<> item-by-item,
+   * i.e. with insertion(s) & comparison(s), which will cause null dereference
+   * during call mdbx_cmp() with zero txn. So it is the workaround for this:
+   *  - explicitly make copies of the `speculums`;
+   *  - explicitly move relevant copy after transaction commit. */
+  SET speculum_committed_copy(ItemCompare(this)),
+      speculum_copy(ItemCompare(this));
+  if (need_speculum_assign) {
+    speculum_committed_copy = speculum_committed;
+    speculum_copy = speculum;
+  }
+
   MDBX_txn *txn = txn_guard.release();
   txn_inject_writefault(txn);
   int rc = mdbx_txn_commit(txn);
@@ -207,9 +219,9 @@ int testcase::breakable_commit() {
   if (need_speculum_assign) {
     need_speculum_assign = false;
     if (unlikely(rc != MDBX_SUCCESS))
-      speculum = speculum_committed;
+      speculum = std::move(speculum_committed_copy);
     else
-      speculum_committed = speculum;
+      speculum_committed = std::move(speculum_copy);
   }
 
   log_trace("<< txn_commit: %s", rc ? "failed" : "Ok");
@@ -465,6 +477,15 @@ void testcase::update_canary(uint64_t increment) {
   log_trace("<< update_canary: sequence = %" PRIu64, canary_now.y);
 }
 
+bool testcase::is_handle_created_in_current_txn(const MDBX_dbi handle,
+                                                MDBX_txn *txn) {
+  unsigned flags, state;
+  int err = mdbx_dbi_flags_ex(txn, handle, &flags, &state);
+  if (unlikely(err != MDBX_SUCCESS))
+    failure_perror("mdbx_dbi_flags_ex()", err);
+  return (state & MDBX_DBI_CREAT) != 0;
+}
+
 int testcase::db_open__begin__table_create_open_clean(MDBX_dbi &handle) {
   db_open();
 
@@ -472,6 +493,9 @@ int testcase::db_open__begin__table_create_open_clean(MDBX_dbi &handle) {
   for (;;) {
     txn_begin(false);
     handle = db_table_open(true);
+
+    if (is_handle_created_in_current_txn(handle, txn_guard.get()))
+      return MDBX_SUCCESS;
     db_table_clear(handle);
     err = breakable_commit();
     if (likely(err == MDBX_SUCCESS)) {
@@ -617,7 +641,8 @@ enum speculum_cursors : int {
   prev = 1,
   prev_prev = 2,
   next = 3,
-  next_next = 4
+  next_next = 4,
+  seek_check = 5
 };
 
 bool testcase::is_same(const Item &a, const Item &b) const {
@@ -691,7 +716,7 @@ void testcase::speculum_check_cursor(const char *where, const char *stage,
   // verbose(where, stage, cursor_key, cursor_data, cursor_err);
   // verbose(where, stage, it);
   if (cursor_err != MDBX_SUCCESS && cursor_err != MDBX_NOTFOUND &&
-      cursor_err != MDBX_RESULT_TRUE)
+      cursor_err != MDBX_RESULT_TRUE && cursor_err != MDBX_ENODATA)
     failure("speculum-%s: %s %s %d %s", where, stage, "cursor-get", cursor_err,
             mdbx_strerror(cursor_err));
 
@@ -714,8 +739,8 @@ void testcase::speculum_check_cursor(const char *where, const char *stage,
                                      const testcase::SET::const_iterator &it,
                                      MDBX_cursor *cursor,
                                      const MDBX_cursor_op op) const {
-  MDBX_val cursor_key = {};
-  MDBX_val cursor_data = {};
+  MDBX_val cursor_key = {0, 0};
+  MDBX_val cursor_data = {0, 0};
   int err;
   if (it != speculum.end() && std::next(it) == speculum.end() &&
       op == MDBX_PREV && (config.params.table_flags & MDBX_DUPSORT)) {
@@ -828,11 +853,26 @@ int testcase::insert(const keygen::buffer &akey, const keygen::buffer &adata,
   int err;
   bool rc = true;
   Item item;
+#if SPECULUM_CURSORS
+  MDBX_cursor *check_seek_cursor = nullptr;
+  MDBX_val seek_check_key, seek_check_data;
+  int seek_check_err = 42;
+#endif /* SPECULUM_CURSORS */
   if (config.params.speculum) {
     item.first = iov2dataview(akey);
     item.second = iov2dataview(adata);
 #if SPECULUM_CURSORS
     speculum_prepare_cursors(item);
+    check_seek_cursor = speculum_cursors[seek_check].get();
+    seek_check_key = akey->value;
+    seek_check_data = adata->value;
+    seek_check_err = mdbx_cursor_get(
+        check_seek_cursor, &seek_check_key, &seek_check_data,
+        (config.params.table_flags & MDBX_DUPSORT) ? MDBX_GET_BOTH
+                                                   : MDBX_SET_KEY);
+    if (seek_check_err != MDBX_SUCCESS && seek_check_err != MDBX_NOTFOUND)
+      failure("speculum-%s: %s pre-insert %d %s", "insert", "seek",
+              seek_check_err, mdbx_strerror(seek_check_err));
 #endif /* SPECULUM_CURSORS */
   }
 
@@ -857,6 +897,26 @@ int testcase::insert(const keygen::buffer &akey, const keygen::buffer &adata,
     }
 
 #if SPECULUM_CURSORS
+    if (insertion_result.second) {
+      if (seek_check_err != MDBX_NOTFOUND) {
+        log_error(
+            "speculum.pre-insert-seek: unexpected %d {%s, %s}", seek_check_err,
+            mdbx_dump_val(&seek_check_key, dump_key, sizeof(dump_key)),
+            mdbx_dump_val(&seek_check_data, dump_value, sizeof(dump_value)));
+        rc = false;
+      }
+    } else {
+      if (seek_check_err != MDBX_SUCCESS) {
+        log_error(
+            "speculum.pre-insert-seek: unexpected %d {%s, %s}", seek_check_err,
+            mdbx_dump_val(&seek_check_key, dump_key, sizeof(dump_key)),
+            mdbx_dump_val(&seek_check_data, dump_value, sizeof(dump_value)));
+        speculum_check_iterator("insert", "pre-seek", insertion_result.first,
+                                seek_check_key, seek_check_data);
+        rc = false;
+      }
+    }
+
     if (insertion_result.first != speculum.begin()) {
       const auto cursor_prev = speculum_cursors[prev].get();
       auto it_prev = insertion_result.first;
@@ -1018,7 +1078,7 @@ bool testcase::speculum_verify() {
   char dump_mkey[128], dump_mvalue[128];
 
   MDBX_cursor *cursor;
-  int err = mdbx_cursor_open(txn_guard.get(), dbi, &cursor);
+  int eof, err = mdbx_cursor_open(txn_guard.get(), dbi, &cursor);
   if (err != MDBX_SUCCESS)
     failure_perror("mdbx_cursor_open()", err);
 
@@ -1026,6 +1086,15 @@ bool testcase::speculum_verify() {
   MDBX_val akey, avalue;
   MDBX_val mkey, mvalue;
   err = mdbx_cursor_get(cursor, &akey, &avalue, MDBX_FIRST);
+  if (err == MDBX_NOTFOUND) {
+    err = mdbx_cursor_get(cursor, &akey, &avalue, MDBX_GET_CURRENT);
+    if (err == MDBX_ENODATA)
+      err = MDBX_NOTFOUND;
+    else {
+      log_error("unexpected %d for MDBX_GET_CURRENT on empty DB", err);
+      rc = false;
+    }
+  }
 
   unsigned extra = 0, lost = 0, n = 0;
   assert(std::is_sorted(speculum.cbegin(), speculum.cend(), ItemCompare(this)));
@@ -1034,14 +1103,20 @@ bool testcase::speculum_verify() {
     if (err != MDBX_SUCCESS) {
       akey.iov_len = avalue.iov_len = 0;
       akey.iov_base = avalue.iov_base = nullptr;
+    } else {
+      eof = mdbx_cursor_eof(cursor);
+      if (eof != MDBX_RESULT_FALSE) {
+        log_error("false-positive cursor-eof %u/%u: db{%s, %s}, rc %i", n,
+                  extra, mdbx_dump_val(&akey, dump_key, sizeof(dump_key)),
+                  mdbx_dump_val(&avalue, dump_value, sizeof(dump_value)), eof);
+        rc = false;
+      }
     }
     const auto S_key = iov2dataview(akey);
     const auto S_data = iov2dataview(avalue);
     if (it != speculum.cend()) {
-      mkey.iov_base = (void *)it->first.c_str();
-      mkey.iov_len = it->first.size();
-      mvalue.iov_base = (void *)it->second.c_str();
-      mvalue.iov_len = it->second.size();
+      mkey = it->first;
+      mvalue = it->second;
     }
     if (err == MDBX_SUCCESS && it != speculum.cend() && S_key == it->first &&
         S_data == it->second) {
@@ -1091,6 +1166,21 @@ bool testcase::speculum_verify() {
     n += 1;
   }
 
+  if (err == MDBX_NOTFOUND) {
+    eof = mdbx_cursor_eof(cursor);
+    if (eof != MDBX_RESULT_TRUE) {
+      eof = mdbx_cursor_eof(cursor);
+      log_error("false-negative cursor-eof: %u, rc %i", n, eof);
+      rc = false;
+    }
+    err = mdbx_cursor_get(cursor, &akey, &avalue, MDBX_GET_CURRENT);
+    if (err == MDBX_SUCCESS)
+      err = mdbx_cursor_get(cursor, &akey, &avalue, MDBX_NEXT);
+    if (err != MDBX_ENODATA) {
+      log_error("unexpected %d for MDBX_GET_CURRENT at EOF", err);
+      rc = false;
+    }
+  }
   mdbx_cursor_close(cursor);
   return rc;
 }

test/test.h

@@ -130,16 +130,12 @@ public:
 };
 
 #define REGISTER_TESTCASE(NAME)                                                \
-  static registry::factory<testcase_##NAME> gRegister_##NAME(ac_##NAME,        \
-                                                             STRINGIFY(NAME))
+  static registry::factory<testcase_##NAME> gRegister_##NAME(                  \
+      ac_##NAME, MDBX_STRINGIFY(NAME))
 
 class testcase {
 protected:
-#if HAVE_cxx17_std_string_view
-  using data_view = std::string_view;
-#else
-  using data_view = std::string;
-#endif
+  using data_view = mdbx::slice;
   static inline data_view iov2dataview(const MDBX_val &v) {
     return (v.iov_base && v.iov_len)
                ? data_view(static_cast<const char *>(v.iov_base), v.iov_len)
@@ -149,7 +145,8 @@ protected:
     return iov2dataview(b->value);
   }
 
-  using Item = std::pair<std::string, std::string>;
+  using Item = std::pair<::mdbx::buffer<>, ::mdbx::buffer<>>;
+
   static MDBX_val dataview2iov(const data_view &v) {
     MDBX_val r;
     r.iov_base = (void *)v.data();
@@ -158,10 +155,13 @@ protected:
   }
   struct ItemCompare {
     const testcase *context;
-    ItemCompare(const testcase *owner) : context(owner) {}
+    ItemCompare(const testcase *owner) : context(owner) {
+      /* The context->txn_guard may be empty/null here */
+    }
 
     bool operator()(const Item &a, const Item &b) const {
       MDBX_val va = dataview2iov(a.first), vb = dataview2iov(b.first);
+      assert(context->txn_guard.get() != nullptr);
       int cmp = mdbx_cmp(context->txn_guard.get(), context->dbi, &va, &vb);
       if (cmp == 0 &&
           (context->config.params.table_flags & MDBX_DUPSORT) != 0) {
@@ -202,7 +202,7 @@ protected:
 #define SPECULUM_CURSORS 1
 #endif /* SPECULUM_CURSORS */
 #if SPECULUM_CURSORS
-  scoped_cursor_guard speculum_cursors[5];
+  scoped_cursor_guard speculum_cursors[5 + 1];
   void speculum_prepare_cursors(const Item &item);
   void speculum_check_cursor(const char *where, const char *stage,
                              const testcase::SET::const_iterator &it,
@@ -268,6 +268,7 @@ protected:
   void db_table_clear(MDBX_dbi handle, MDBX_txn *txn = nullptr);
   void db_table_close(MDBX_dbi handle);
   int db_open__begin__table_create_open_clean(MDBX_dbi &handle);
+  bool is_handle_created_in_current_txn(const MDBX_dbi handle, MDBX_txn *txn);
 
   bool wait4start();
   void report(size_t nops_done);

test/utils.cc

@@ -101,164 +101,6 @@ bool is_samedata(const MDBX_val *a, const MDBX_val *b) {
 
 //-----------------------------------------------------------------------------
 
-/* TODO: replace my 'libmera' from t1ha. */
-uint64_t entropy_ticks(void) {
-#if defined(EMSCRIPTEN)
-  return (uint64_t)emscripten_get_now();
-#endif /* EMSCRIPTEN */
-
-#if defined(__APPLE__) || defined(__MACH__)
-  return mach_absolute_time();
-#endif /* defined(__APPLE__) || defined(__MACH__) */
-
-#if defined(__sun__) || defined(__sun)
-  return gethrtime();
-#endif /* __sun__ */
-
-#if defined(__GNUC__) || defined(__clang__)
-
-#if defined(__ia64__)
-  uint64_t ticks;
-  __asm __volatile("mov %0=ar.itc" : "=r"(ticks));
-  return ticks;
-#elif defined(__hppa__)
-  uint64_t ticks;
-  __asm __volatile("mfctl 16, %0" : "=r"(ticks));
-  return ticks;
-#elif defined(__s390__)
-  uint64_t ticks;
-  __asm __volatile("stck 0(%0)" : : "a"(&(ticks)) : "memory", "cc");
-  return ticks;
-#elif defined(__alpha__)
-  uint64_t ticks;
-  __asm __volatile("rpcc %0" : "=r"(ticks));
-  return ticks;
-#elif defined(__sparc__) || defined(__sparc) || defined(__sparc64__) ||        \
-    defined(__sparc64) || defined(__sparc_v8plus__) ||                         \
-    defined(__sparc_v8plus) || defined(__sparc_v8plusa__) ||                   \
-    defined(__sparc_v8plusa) || defined(__sparc_v9__) || defined(__sparc_v9)
-
-  union {
-    uint64_t u64;
-    struct {
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-      uint32_t h, l;
-#else
-      uint32_t l, h;
-#endif
-    } u32;
-  } cycles;
-
-#if defined(__sparc_v8plus__) || defined(__sparc_v8plusa__) ||                 \
-    defined(__sparc_v9__) || defined(__sparc_v8plus) ||                        \
-    defined(__sparc_v8plusa) || defined(__sparc_v9)
-
-#if UINTPTR_MAX > 0xffffFFFFul || ULONG_MAX > 0xffffFFFFul ||                  \
-    defined(__sparc64__) || defined(__sparc64)
-  __asm __volatile("rd %%tick, %0" : "=r"(cycles.u64));
-#else
-  __asm __volatile("rd %%tick, %1; srlx %1, 32, %0"
-                   : "=r"(cycles.u32.h), "=r"(cycles.u32.l));
-#endif /* __sparc64__ */
-
-#else
-  __asm __volatile(".byte 0x83, 0x41, 0x00, 0x00; mov %%g1, %0"
-                   : "=r"(cycles.u64)
-                   :
-                   : "%g1");
-#endif /* __sparc8plus__ || __sparc_v9__ */
-  return cycles.u64;
-
-#elif (defined(__powerpc64__) || defined(__ppc64__) || defined(__ppc64) ||     \
-       defined(__powerpc64))
-  uint64_t ticks;
-  __asm __volatile("mfspr %0, 268" : "=r"(ticks));
-  return ticks;
-#elif (defined(__powerpc__) || defined(__ppc__) || defined(__powerpc) ||       \
-       defined(__ppc))
-#if UINTPTR_MAX > 0xffffFFFFul || ULONG_MAX > 0xffffFFFFul
-  uint64_t ticks;
-  __asm __volatile("mftb  %0" : "=r"(ticks));
-  *now = ticks;
-#else
-  uint64_t ticks;
-  uint32_t low, high_before, high_after;
-  __asm __volatile("mftbu %0; mftb  %1; mftbu %2"
-                   : "=r"(high_before), "=r"(low), "=r"(high_after));
-  ticks = (uint64_t)high_after << 32;
-  ticks |= low & /* zeroes if high part has changed */
-           ~(high_before - high_after);
-#endif
-#elif (defined(__aarch64__) || (defined(__ARM_ARCH) && __ARM_ARCH > 7)) &&     \
-    !defined(MDBX_SAFE4QEMU)
-  uint64_t virtual_timer;
-  __asm __volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer));
-  return virtual_timer;
-#elif (defined(__ARM_ARCH) && __ARM_ARCH > 5 && __ARM_ARCH < 8) ||             \
-    defined(_M_ARM)
-  static uint32_t pmcntenset = 0x00425B00;
-  if (unlikely(pmcntenset == 0x00425B00)) {
-    uint32_t pmuseren;
-#ifdef _M_ARM
-    pmuseren = _MoveFromCoprocessor(15, 0, 9, 14, 0);
-#else
-    __asm("mrc p15, 0, %0, c9, c14, 0" : "=r"(pmuseren));
-#endif
-    if (1 & pmuseren /* Is it allowed for user mode code? */) {
-#ifdef _M_ARM
-      pmcntenset = _MoveFromCoprocessor(15, 0, 9, 12, 1);
-#else
-      __asm("mrc p15, 0, %0, c9, c12, 1" : "=r"(pmcntenset));
-#endif
-    } else
-      pmcntenset = 0;
-  }
-  if (pmcntenset & 0x80000000ul /* Is it counting? */) {
-#ifdef _M_ARM
-    return __rdpmccntr64();
-#else
-    uint32_t pmccntr;
-    __asm __volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(pmccntr));
-    return pmccntr;
-#endif
-  }
-#elif ((defined(_MIPS_ISA) && defined(_MIPS_ISA_MIPS2) &&                      \
-        _MIPS_ISA >= _MIPS_ISA_MIPS2) ||                                       \
-       (defined(__mips) && __mips >= 2) || defined(_R4000)) &&                 \
-    !defined(MDBX_SAFE4QEMU) /* QEMU may not emulate the CC register           \
-                               (High-resolution cycle counter) */
-  unsigned count;
-  __asm __volatile("rdhwr %0, $2" : "=r"(count));
-  return count;
-#endif                       /* arch selector */
-#endif                       /* __GNUC__ || __clang__ */
-
-#if defined(__e2k__) || defined(__ia32__)
-  return __rdtsc();
-#elif defined(_WIN32) || defined(_WIN64) || defined(_WINDOWS)
-  LARGE_INTEGER PerformanceCount;
-  if (QueryPerformanceCounter(&PerformanceCount))
-    return PerformanceCount.QuadPart;
-  return GetTickCount64();
-#else
-  struct timespec ts;
-#if defined(CLOCK_MONOTONIC_COARSE)
-  clockid_t clk_id = CLOCK_MONOTONIC_COARSE;
-#elif defined(CLOCK_MONOTONIC_RAW)
-  clockid_t clk_id = CLOCK_MONOTONIC_RAW;
-#else
-  clockid_t clk_id = CLOCK_MONOTONIC;
-#endif
-  int rc = clock_gettime(clk_id, &ts);
-  if (unlikely(rc))
-    failure_perror("clock_gettime()", rc);
-
-  return (((uint64_t)ts.tv_sec) << 32) + ts.tv_nsec;
-#endif
-}
-
-//-----------------------------------------------------------------------------
-
 uint64_t prng64_white(uint64_t &state) {
   state = prng64_map2_careless(state);
   return bleach64(state);
@@ -303,8 +145,6 @@ uint64_t prng64(void) { return prng64_white(prng_state); }
 
 void prng_fill(void *ptr, size_t bytes) { prng_fill(prng_state, ptr, bytes); }
 
-uint64_t entropy_white() { return bleach64(entropy_ticks()); }
-
 double double_from_lower(uint64_t salt) {
 #ifdef IEEE754_DOUBLE_BIAS
   ieee754_double r;
@@ -336,25 +176,25 @@ double double_from_upper(uint64_t salt) {
 #endif
 }
 
-bool flipcoin() { return bleach32((uint32_t)entropy_ticks()) & 1; }
-bool flipcoin_x2() { return (bleach32((uint32_t)entropy_ticks()) & 3) == 0; }
-bool flipcoin_x3() { return (bleach32((uint32_t)entropy_ticks()) & 7) == 0; }
-bool flipcoin_x4() { return (bleach32((uint32_t)entropy_ticks()) & 15) == 0; }
+bool flipcoin() { return prng32() & 1; }
+bool flipcoin_x2() { return (prng32() & 3) == 0; }
+bool flipcoin_x3() { return (prng32() & 7) == 0; }
+bool flipcoin_x4() { return (prng32() & 15) == 0; }
 bool flipcoin_n(unsigned n) {
-  return (bleach64(entropy_ticks()) & ((UINT64_C(1) << n) - 1)) == 0;
+  return (prng64() & ((UINT64_C(1) << n) - 1)) == 0;
 }
 
 bool jitter(unsigned probability_percent) {
   const uint32_t top = UINT32_MAX - UINT32_MAX % 100;
   uint32_t dice, edge = (top) / 100 * probability_percent;
   do
-    dice = bleach32((uint32_t)entropy_ticks());
+    dice = prng32();
   while (dice >= top);
   return dice < edge;
 }
 
 void jitter_delay(bool extra) {
-  unsigned dice = entropy_white() & 3;
+  unsigned dice = prng32() & 3;
   if (dice == 0) {
     log_trace("== jitter.no-delay");
   } else {
@@ -367,8 +207,8 @@ void jitter_delay(bool extra) {
         osal_yield();
         cpu_relax();
         if (dice > 2) {
-          unsigned us = entropy_white() &
-                        (extra ? 0xffff /* 656 ms */ : 0x3ff /* 1 ms */);
+          unsigned us =
+              prng32() & (extra ? 0xffff /* 656 ms */ : 0x3ff /* 1 ms */);
           log_trace("== jitter.delay: %0.6f", us / 1000000.0);
           osal_udelay(us);
         }

test/utils.h

@@ -292,8 +292,6 @@ inline bool is_samedata(const MDBX_val &a, const MDBX_val &b) {
 }
 std::string format(const char *fmt, ...);
 
-uint64_t entropy_ticks(void);
-uint64_t entropy_white(void);
 static inline uint64_t bleach64(uint64_t v) {
   // Tommy Ettinger, https://www.blogger.com/profile/04953541827437796598
   // http://mostlymangling.blogspot.com/2019/01/better-stronger-mixer-and-test-procedure.html

test/valgrind_suppress.txt

@@ -22,6 +22,14 @@
    ...
    fun:mdbx_mapresize
 }
+{
+   msync-wipe-steady
+   Memcheck:Param
+   msync(start)
+   fun:msync
+   ...
+   fun:mdbx_wipe_steady
+}
 
 # single-page flush by pwrite()
 {
@@ -42,16 +50,15 @@
 }
 
 # modern Valgrind don't support the `vector[...]` pattern
+#{
+#   pwritev-page-flush
+#   Memcheck:Param
+#   pwritev(vector[...])
+#   fun:pwritev
+#   ...
+#   fun:mdbx_iov_write*
+#}
 # for((i=0;i<64;++i)); do echo -e "{\n   pwritev-page-flush-$i\n   Memcheck:Param\n   pwritev(vector[$i])\n   fun:pwritev\n   ...\n   fun:mdbx_iov_write*\n}"; done >> valgrind_suppress.txt
-
-{
-   pwritev-page-flush
-   Memcheck:Param
-   pwritev(vector[...])
-   fun:pwritev
-   ...
-   fun:mdbx_iov_write*
-}
 {
    pwritev-page-flush-0
    Memcheck:Param