mdbx: Happy New Year! (release v0.11.3).

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

 - [gcxfd <i@rmw.link>](https://github.com/gcxfd) for reporting, contributing and testing.
 - [장세연 (Чан Се Ен)](https://github.com/sasgas) for reporting and testing.
 - [Alex Sharov](https://github.com/AskAlexSharov) for reporting, testing and provide resources for remote debugging/investigation.

New features, extensions and improvements:
------------------------------------------

 - [Added](https://github.com/erthink/libmdbx/issues/236) `mdbx_cursor_get_batch()`.
 - [Added](https://github.com/erthink/libmdbx/issues/250) `MDBX_SET_UPPERBOUND`.
 - C++ API is finalized now.
 - The GC update stage has been [significantly speeded](https://github.com/erthink/libmdbx/issues/254) when fixing huge Erigon's transactions (Ethereum ecosystem).

Fixes:
------

 - Disabled C++20 concepts for stupid AppleClang 13.x
 - Fixed internal collision of `MDBX_SHRINK_ALLOWED` with `MDBX_ACCEDE`.

Minors:
-------

 - Fixed returning `MDBX_RESULT_TRUE` (unexpected -1) from `mdbx_env_set_option()`.
 - Added `mdbx_env_get_syncbytes()` and `mdbx_env_get_syncperiod()`.
 - [Clarified](https://github.com/erthink/libmdbx/pull/249) description of `MDBX_INTEGERKEY`.
 - Reworked/simplified `mdbx_env_sync_internal()`.
 - [Fixed](https://github.com/erthink/libmdbx/issues/248) extra assertion inside `mdbx_cursor_put()` for `MDBX_DUPFIXED` cases.
 - Avoiding extra looping inside `mdbx_env_info_ex()`.
 - Explicitly enabled core dumps from stochastic tests scripts on Linux.
 - [Fixed](https://github.com/erthink/libmdbx/issues/253) `mdbx_override_meta()` to avoid false-positive assertions.
 - For compatibility reverted returning `MDBX_ENODATA`for some cases.

Signed-off-by: Leonid Yuriev <leo@yuriev.ru>

.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/0x19291d8658f762f3baceae1700c0b9466572ceab']
+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/expect.txt

@@ -68,6 +68,7 @@ asprintf
 aspx
 assection
 AstraLinux
+astralinux
 atal
 atexit
 atfork
@@ -99,6 +100,7 @@ bfin
 biarch
 bibtex
 BIGDATA
+bigdata
 bindir
 binfmt
 binutils
@@ -458,6 +460,7 @@ EPERM
 EPIPE
 erasevolume
 EREMOTE
+Erigon
 EROFS
 errcode
 errno
@@ -574,6 +577,7 @@ gcda
 GCFREEZE
 gcno
 gcov
+gcxfd
 gdiplus
 getenv
 gethostid
@@ -600,6 +604,7 @@ github
 githubusercontent
 gitignore
 glibc
+GLIBCXX
 globals
 gmail
 gmake
@@ -709,6 +714,7 @@ inprocess
 INSTEADOF
 integerdup
 integerkey
+interoperability
 interprocedural
 intlimits
 intptr
@@ -978,6 +984,7 @@ microsoft
 Mikkelson
 minflt
 MINGW
+mingw
 minimalistic
 minkeys
 minlen
@@ -1276,6 +1283,7 @@ pmax
 pmccntr
 pmcntenset
 pmedvedev
+pmeta
 pmr
 pmuseren
 pmwkaa
@@ -1315,6 +1323,7 @@ proba
 proces
 procfs
 progname
+programdata
 PROGRAMLISTING
 projectbrief
 projectlogo
@@ -1403,11 +1412,13 @@ REALMEM
 REALPATH
 realtime
 Rebuffo
+rebuffo
 RECO
 redis
 reedom
 reefont
 refname
+refreshenv
 REGEX
 regexp
 reinited
@@ -1436,6 +1447,7 @@ rlock
 rlt
 rmdir
 RMID
+rmw
 rocksdb
 rolledback
 roolback
@@ -1812,6 +1824,7 @@ unspilling
 unsync
 UNTRACK
 updation
+UPPERBOUND
 upsert
 UPSERTING
 upsertion

.github/workflows/MinGW.yml

@@ -27,38 +27,39 @@ jobs:
     - uses: actions/checkout@v2
     - name: fetch tags
       run: git fetch --unshallow --tags --prune --force
+    - name: append PATH
+      run: echo 'C:/ProgramData/chocolatey/lib/mingw/tools/install/mingw64/bin' >> $GITHUB_PATH
     - name: update mingw64
       # wanna version >= 10.2
-      run: choco upgrade mingw -y --no-progress
+      run: choco upgrade mingw -y --no-progress && refreshenv
     - name: configure-dll
-      run: mkdir build-dll && cd build-dll && cmake  -G "MinGW Makefiles" -DMDBX_BUILD_SHARED_LIBRARY:BOOL=ON -DMDBX_INSTALL_STATIC:BOOL=OFF ..
+      shell: bash
+      run: |
+        mkdir build-dll && cd build-dll && \
+        cmake -G "MinGW Makefiles" -DMDBX_BUILD_SHARED_LIBRARY:BOOL=ON -DMDBX_INSTALL_STATIC:BOOL=OFF -DMDBX_ENABLE_TESTS:BOOL=ON ..
     - name: build-dll
+      shell: bash
       run: cd build-dll && cmake --build .
     - name: test-dll
-      shell: pwsh
+      shell: bash
       run: |
-        cd build-dll
-        ls
-        ./mdbx_test --progress --console=no --pathname=test.db --dont-cleanup-after basic > test.log
-        Get-Content test.log | Select-Object -last 42
-        if ($LastExitCode -ne 0) {
-            throw "Exec: $ErrorMessage"
-        } else {
-            ./mdbx_chk -nvv test.db | Tee-Object -file chk.log | Select-Object -last 42
-        }
+        export "PATH=/c/programdata/chocolatey/lib/mingw/tools/install/mingw64/bin:$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
-      run: mkdir build-static && cd build-static && cmake  -G "MinGW Makefiles" -DMDBX_BUILD_SHARED_LIBRARY:BOOL=OFF -DMDBX_INSTALL_STATIC:BOOL=ON ..
-    - name: build-static
-      run: cd build-static && cmake --build .
-    - name: test-static
-      shell: pwsh
+      shell: bash
       run: |
-        cd build-static
-        ls
-        ./mdbx_test --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: $ErrorMessage"
-        } else {
-            ./mdbx_chk -nvv test.db | Tee-Object -file chk.log | Select-Object -last 42
-        }
+        mkdir build-static && cd build-static && \
+        cmake -G "MinGW Makefiles" -DMDBX_BUILD_SHARED_LIBRARY:BOOL=OFF -DMDBX_INSTALL_STATIC:BOOL=ON -DMDBX_ENABLE_TESTS:BOOL=ON ..
+    - name: build-static
+      shell: bash
+      run: |
+        cd build-static && cmake --build .
+    - name: test-static
+      shell: bash
+      run: |
+        export "PATH=/c/programdata/chocolatey/lib/mingw/tools/install/mingw64/bin:$PATH" && \
+        cd build-static && \
+        ./mdbx_test.exe --progress --console=no --pathname=test.db --dont-cleanup-after basic && \
+        ./mdbx_chk.exe -nvv test.db

CMakeLists.txt

@@ -93,6 +93,10 @@ else()
 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)
@@ -294,11 +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
@@ -334,11 +338,18 @@ 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_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))
+      AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10))
     set(MDBX_CXX_STANDARD 20)
   elseif(NOT HAS_CXX17 LESS 0
       AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5))
@@ -423,7 +434,7 @@ endif()
 #           ####   #          #       #     ####   #    #   ####
 #
 
-set(MDBX_BUILD_OPTIONS ENABLE_ASAN MDBX_USE_VALGRIND ENABLE_GPROF ENABLE_GCOV)
+set(MDBX_BUILD_OPTIONS ENABLE_UBSAN ENABLE_ASAN MDBX_USE_VALGRIND ENABLE_GPROF ENABLE_GCOV)
 macro(add_mdbx_option NAME DESCRIPTION DEFAULT)
   list(APPEND MDBX_BUILD_OPTIONS ${NAME})
   if(NOT ${DEFAULT} STREQUAL "AUTO")
@@ -852,7 +863,7 @@ else()
 endif()
 
 # options
-set(options VERSION C_COMPILER CXX_COMPILER MDBX_BUILD_TARGET MDBX_BUILD_TYPE)
+set(options VERSION C_COMPILER CXX_COMPILER MDBX_BUILD_TARGET MDBX_BUILD_TYPE ${MDBX_BUILD_OPTIONS})
 foreach(item IN LISTS options)
   if(DEFINED ${item})
     set(value "${${item}}")
@@ -863,7 +874,7 @@ foreach(item IN LISTS options)
     set(item CMAKE_${item})
     set(value "${${item}}")
   else()
-    set(value "undefined")
+    set(value "AUTO (not pre-defined explicitly)")
   endif()
   message(STATUS "${item}: ${value}")
 endforeach(item)

ChangeLog.md

@@ -1,8 +1,6 @@
 ChangeLog
 ---------
 
-## v0.11.x (in development)
-
 ### TODO
 
  - [Engage an "overlapped I/O" on Windows](https://github.com/erthink/libmdbx/issues/224).
@@ -16,11 +14,96 @@ ChangeLog
  - [Support for RAW devices](https://github.com/erthink/libmdbx/issues/124).
  - [Support MessagePack for Keys & Values](https://github.com/erthink/libmdbx/issues/115).
  - [Engage new terminology](https://github.com/erthink/libmdbx/issues/137).
- - Finalize C++ API (few typos and bugs are still maybe for now).
  - Packages for [Astra Linux](https://astralinux.ru/), [ALT Linux](https://www.altlinux.org/), [ROSA Linux](https://www.rosalinux.ru/), etc.
 
 
-## v0.10.5 at 2021-10-13
+## v0.11.3 at 2021-12-31
+
+Acknowledgements:
+
+ - [gcxfd <i@rmw.link>](https://github.com/gcxfd) for reporting, contributing and testing.
+ - [장세연 (Чан Се Ен)](https://github.com/sasgas) for reporting and testing.
+ - [Alex Sharov](https://github.com/AskAlexSharov) for reporting, testing and provide resources for remote debugging/investigation.
+
+New features, extensions and improvements:
+
+ - [Added](https://github.com/erthink/libmdbx/issues/236) `mdbx_cursor_get_batch()`.
+ - [Added](https://github.com/erthink/libmdbx/issues/250) `MDBX_SET_UPPERBOUND`.
+ - C++ API is finalized now.
+ - The GC update stage has been [significantly speeded](https://github.com/erthink/libmdbx/issues/254) when fixing huge Erigon's transactions (Ethereum ecosystem).
+
+Fixes:
+
+ - Disabled C++20 concepts for stupid AppleClang 13.x
+ - Fixed internal collision of `MDBX_SHRINK_ALLOWED` with `MDBX_ACCEDE`.
+
+Minors:
+
+ - Fixed returning `MDBX_RESULT_TRUE` (unexpected -1) from `mdbx_env_set_option()`.
+ - Added `mdbx_env_get_syncbytes()` and `mdbx_env_get_syncperiod()`.
+ - [Clarified](https://github.com/erthink/libmdbx/pull/249) description of `MDBX_INTEGERKEY`.
+ - Reworked/simplified `mdbx_env_sync_internal()`.
+ - [Fixed](https://github.com/erthink/libmdbx/issues/248) extra assertion inside `mdbx_cursor_put()` for `MDBX_DUPFIXED` cases.
+ - Avoiding extra looping inside `mdbx_env_info_ex()`.
+ - Explicitly enabled core dumps from stochastic tests scripts on Linux.
+ - [Fixed](https://github.com/erthink/libmdbx/issues/253) `mdbx_override_meta()` to avoid false-positive assertions.
+ - For compatibility reverted returning `MDBX_ENODATA`for some cases.
+
+
+## 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:
 
@@ -35,14 +118,14 @@ Fixes:
 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.
+ - 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/mdbx-rs).
+ - [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:

GNUmakefile

@@ -35,7 +35,7 @@ CFLAGS  ?= -std=gnu11 -O2 -g -Wall -Werror -Wextra -Wpedantic -ffunction-section
 # -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))
 
 # TIP: Try append '--no-as-needed,-lrt' for ability to built with modern glibc, but then use with the old.

README.md

@@ -2,7 +2,7 @@
 
 > Please refer to the online [documentation](https://erthink.github.io/libmdbx/)
 > with [`C` API description](https://erthink.github.io/libmdbx/group__c__api.html)
-> and pay attention to the preliminary [`C++` API](https://github.com/erthink/libmdbx/blob/devel/mdbx.h%2B%2B).
+> and pay attention to the [`C++` API](https://github.com/erthink/libmdbx/blob/devel/mdbx.h%2B%2B).
 >
 > Questions, feedback and suggestions are welcome to the [Telegram' group](https://t.me/libmdbx).
 >
@@ -565,14 +565,15 @@ 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-store](https://github.com/kriszyp/lmdbx-store) | [Kris Zyp](https://github.com/kriszyp/)
+| 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    | [mdbx-rs](https://github.com/vorot93/mdbx-rs)   | [Artem Vorotnikov](https://github.com/vorot93) |
-| Java (obsolete)   | [mdbxjni](https://github.com/castortech/mdbxjni)   | [Castor Technologies](https://castortech.com/) |
+| Rust    | [libmdbx-rs](https://github.com/vorot93/libmdbx-rs)   | [Artem Vorotnikov](https://github.com/vorot93) |
+| Rust    | [mdbx](https://crates.io/crates/mdbx)                 | [gcxfd](https://github.com/gcxfd) |
+| Java    | [mdbxjni](https://github.com/castortech/mdbxjni)      | [Castor Technologies](https://castortech.com/) |
+| Python (draft)  | [python-bindings](https://github.com/erthink/libmdbx/commits/python-bindings) branch | [Noel Kuntze](https://github.com/Thermi)
 | .NET (obsolete) | [mdbx.NET](https://github.com/wangjia184/mdbx.NET) | [Jerry Wang](https://github.com/wangjia184) |
 
 <!-- section-end -->

appveyor.yml

@@ -1,4 +1,4 @@
-version: 0.11.0.{build}
+version: 0.11.3.{build}
 
 environment:
   matrix:

cmake/compiler.cmake

@@ -178,7 +178,7 @@ if(NOT DEFINED CMAKE_TARGET_BITNESS)
   endif()
 endif()
 
-if(CMAKE_COMPILER_IS_ELBRUSC OR CMAKE_SYSTEM_PROCESSOR MATCHES "e2k.*|E2K.*|elbrus.*|ELBRUS.*")
+if(CMAKE_COMPILER_IS_ELBRUSC OR CMAKE_COMPILER_IS_ELBRUSCXX OR CMAKE_SYSTEM_PROCESSOR MATCHES "e2k.*|E2K.*|elbrus.*|ELBRUS.*")
   set(E2K TRUE)
   set(CMAKE_SYSTEM_ARCH "Elbrus")
 elseif((MSVC64 OR MINGW64) AND CMAKE_TARGET_BITNESS EQUAL 64)
@@ -271,7 +271,7 @@ if(CMAKE_CXX_COMPILER_LOADED)
 endif()
 
 # Check for LTO support by GCC
-if(CMAKE_COMPILER_IS_GNU${CMAKE_PRIMARY_LANG})
+if(CMAKE_COMPILER_IS_GNU${CMAKE_PRIMARY_LANG} AND NOT CMAKE_COMPILER_IS_ELBRUSC AND NOT CMAKE_COMPILER_IS_ELBRUSCXX)
   unset(gcc_collect)
   unset(gcc_lto_wrapper)
 

mdbx.h

@@ -172,6 +172,9 @@ as a duplicates or as like a multiple values corresponds to keys.
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
+#if !defined(NDEBUG) && !defined(assert)
+#include <assert.h>
+#endif /* NDEBUG */
 
 #if defined(_WIN32) || defined(_WIN64)
 #include <windows.h>
@@ -393,7 +396,8 @@ 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__)) ||                             \
@@ -410,7 +414,7 @@ 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__)) ||                                                    \
@@ -1382,29 +1386,32 @@ 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
-   * must all be of the same size and must be aligned while passing as
+  /** Numeric keys in native byte order either uint32_t or uint64_t
+   * (must be one of uint32_t or uint64_t, other integer types, for example,
+   * signed integer or uint16_t will not work).
+   * The keys must all be of the same size and must be aligned while passing as
    * 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.
@@ -1565,18 +1572,33 @@ enum MDBX_cursor_op {
    * a page of duplicate data items. */
   MDBX_PREV_MULTIPLE,
 
-  /** Position at first key-value pair greater than or equal to specified,
-   * return both key and data, and the return code depends on a exact match.
+  /** Positions cursor at first key-value pair greater than or equal to
+   * specified, return both key and data, and the return code depends on whether
+   * a exact match.
    *
    * For non DUPSORT-ed collections this work the same to \ref MDBX_SET_RANGE,
-   * but returns \ref MDBX_SUCCESS if key found exactly and
+   * but returns \ref MDBX_SUCCESS if key found exactly or
    * \ref MDBX_RESULT_TRUE if greater key was found.
    *
    * For DUPSORT-ed a data value is taken into account for duplicates,
    * i.e. for a pairs/tuples of a key and an each data value of duplicates.
-   * Returns \ref MDBX_SUCCESS if key-value pair found exactly and
+   * Returns \ref MDBX_SUCCESS if key-value pair found exactly or
    * \ref MDBX_RESULT_TRUE if the next pair was returned. */
-  MDBX_SET_LOWERBOUND
+  MDBX_SET_LOWERBOUND,
+
+  /** Positions cursor at first key-value pair greater than specified,
+   * return both key and data, and the return code depends on whether a
+   * upper-bound was found.
+   *
+   * For non DUPSORT-ed collections this work the same to \ref MDBX_SET_RANGE,
+   * but returns \ref MDBX_SUCCESS if the greater key was found or
+   * \ref MDBX_NOTFOUND otherwise.
+   *
+   * For DUPSORT-ed a data value is taken into account for duplicates,
+   * i.e. for a pairs/tuples of a key and an each data value of duplicates.
+   * Returns \ref MDBX_SUCCESS if the greater pair was returned or
+   * \ref MDBX_NOTFOUND otherwise. */
+  MDBX_SET_UPPERBOUND
 };
 #ifndef __cplusplus
 /** \ingroup c_cursors */
@@ -1735,7 +1757,7 @@ 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,
@@ -2427,6 +2449,7 @@ LIBMDBX_INLINE_API(int, mdbx_env_sync_poll, (MDBX_env * env)) {
 /** \brief Sets threshold to force flush the data buffers to disk, even any of
  * \ref MDBX_SAFE_NOSYNC flag in the environment.
  * \ingroup c_settings
+ * \see mdbx_env_get_syncbytes \see MDBX_opt_sync_bytes
  *
  * The threshold value affects all processes which operates with given
  * environment until the last process close environment or a new value will be
@@ -2451,11 +2474,39 @@ LIBMDBX_INLINE_API(int, mdbx_env_set_syncbytes,
   return mdbx_env_set_option(env, MDBX_opt_sync_bytes, threshold);
 }
 
+/** \brief Get threshold to force flush the data buffers to disk, even any of
+ * \ref MDBX_SAFE_NOSYNC flag in the environment.
+ * \ingroup c_statinfo
+ * \see mdbx_env_set_syncbytes() \see MDBX_opt_sync_bytes
+ *
+ * \param [in] env       An environment handle returned
+ *                       by \ref mdbx_env_create().
+ * \param [out] threshold  Address of an size_t to store
+ *                         the number of bytes of summary changes when
+ *                         a synchronous flush would be made.
+ *
+ * \returns A non-zero error value on failure and 0 on success,
+ *          some possible errors are:
+ * \retval MDBX_EINVAL   An invalid parameter was specified. */
+LIBMDBX_INLINE_API(int, mdbx_env_get_syncbytes,
+                   (const MDBX_env *env, size_t *threshold)) {
+  int rc = MDBX_EINVAL;
+  if (threshold) {
+    uint64_t proxy = 0;
+    rc = mdbx_env_get_option(env, MDBX_opt_sync_bytes, &proxy);
+#ifdef assert
+    assert(proxy <= SIZE_MAX);
+#endif /* assert */
+    *threshold = (size_t)proxy;
+  }
+  return rc;
+}
+
 /** \brief Sets relative period since the last unsteady commit to force flush
  * the data buffers to disk, even of \ref MDBX_SAFE_NOSYNC flag in the
  * environment.
- *
  * \ingroup c_settings
+ * \see mdbx_env_get_syncperiod \see MDBX_opt_sync_period
  *
  * The relative period value affects all processes which operates with given
  * environment until the last process close environment or a new value will be
@@ -2486,6 +2537,36 @@ LIBMDBX_INLINE_API(int, mdbx_env_set_syncperiod,
   return mdbx_env_set_option(env, MDBX_opt_sync_period, seconds_16dot16);
 }
 
+/** \brief Get relative period since the last unsteady commit to force flush
+ * the data buffers to disk, even of \ref MDBX_SAFE_NOSYNC flag in the
+ * environment.
+ * \ingroup c_statinfo
+ * \see mdbx_env_set_syncperiod() \see MDBX_opt_sync_period
+ *
+ * \param [in] env       An environment handle returned
+ *                       by \ref mdbx_env_create().
+ * \param [out] period_seconds_16dot16  Address of an size_t to store
+ *                                      the period in 1/65536 of second when
+ *                                      a synchronous flush would be made since
+ *                                      the last unsteady commit.
+ *
+ * \returns A non-zero error value on failure and 0 on success,
+ *          some possible errors are:
+ * \retval MDBX_EINVAL   An invalid parameter was specified. */
+LIBMDBX_INLINE_API(int, mdbx_env_get_syncperiod,
+                   (const MDBX_env *env, unsigned *period_seconds_16dot16)) {
+  int rc = MDBX_EINVAL;
+  if (period_seconds_16dot16) {
+    uint64_t proxy = 0;
+    rc = mdbx_env_get_option(env, MDBX_opt_sync_period, &proxy);
+#ifdef assert
+    assert(proxy <= UINT32_MAX);
+#endif /* assert */
+    *period_seconds_16dot16 = (unsigned)proxy;
+  }
+  return rc;
+}
+
 /** \brief Close the environment and release the memory map.
  * \ingroup c_opening
  *
@@ -3284,9 +3365,11 @@ 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;
@@ -3509,10 +3592,14 @@ LIBMDBX_API int mdbx_canary_get(const MDBX_txn *txn, MDBX_canary *canary);
  * 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.
+ *     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. */
+ *     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;
 
@@ -4261,6 +4348,43 @@ LIBMDBX_API int mdbx_cursor_copy(const MDBX_cursor *src, MDBX_cursor *dest);
 LIBMDBX_API int mdbx_cursor_get(MDBX_cursor *cursor, MDBX_val *key,
                                 MDBX_val *data, MDBX_cursor_op op);
 
+/** \brief Retrieve multiple non-dupsort key/value pairs by cursor.
+ * \ingroup c_crud
+ *
+ * This function retrieves multiple key/data pairs from the database without
+ * \ref MDBX_DUPSORT option. For `MDBX_DUPSORT` databases please
+ * use \ref MDBX_GET_MULTIPLE and \ref MDBX_NEXT_MULTIPLE.
+ *
+ * The number of key and value items is returned in the `size_t count`
+ * refers. The addresses and lengths of the keys and values are returned in the
+ * array to which `pairs` refers.
+ * \see mdbx_cursor_get()
+ *
+ * \param [in] cursor     A cursor handle returned by \ref mdbx_cursor_open().
+ * \param [out] count     The number of key and value item returned, on success
+ *                        it always be the even because the key-value
+ *                        pairs are returned.
+ * \param [in,out] pairs  A pointer to the array of key value pairs.
+ * \param [in] limit      The size of pairs buffer as the number of items,
+ *                        but not a pairs.
+ * \param [in] op         A cursor operation \ref MDBX_cursor_op (only
+ *                        \ref MDBX_FIRST, \ref MDBX_NEXT, \ref MDBX_GET_CURRENT
+ *                        are supported).
+ *
+ * \returns A non-zero error value on failure and 0 on success,
+ *          some possible errors are:
+ * \retval MDBX_THREAD_MISMATCH  Given transaction is not owned
+ *                               by current thread.
+ * \retval MDBX_NOTFOUND         No more key-value pairs are available.
+ * \retval MDBX_ENODATA          The cursor is already at the end of data.
+ * \retval MDBX_RESULT_TRUE      The specified limit is less than the available
+ *                               key-value pairs on the current page/position
+ *                               that the cursor points to.
+ * \retval MDBX_EINVAL           An invalid parameter was specified. */
+LIBMDBX_API int mdbx_cursor_get_batch(MDBX_cursor *cursor, size_t *count,
+                                      MDBX_val *pairs, size_t limit,
+                                      MDBX_cursor_op op);
+
 /** \brief Store by cursor.
  * \ingroup c_crud
  *

mdbx.h++

@@ -1,15 +1,16 @@
 /// \file mdbx.h++
-/// \brief The libmdbx C++ API header file (preliminary).
+/// \brief The libmdbx C++ API header file.
 ///
 /// \author Copyright (c) 2020-2021, Leonid Yuriev <leo@yuriev.ru>.
 /// \copyright SPDX-License-Identifier: Apache-2.0
 ///
 /// Tested with:
-///  - LCC >= 1.23 (http://www.mcst.ru/lcc),
-///  - GNU C++ >= 4.8,
-///  - clang >= 4.0,
-///  - MSVC >= 19.0 (Visual Studio 2015),
-///    but 19.2x could hang due optimizer bug.
+///  - Elbrus LCC >= 1.23 (http://www.mcst.ru/lcc);
+///  - GNU C++ >= 4.8;
+///  - clang >= 3.9;
+///  - MSVC >= 14.0 (Visual Studio 2015),
+///    but 19.2x could hang due optimizer bug;
+///  - AppleClang, but without C++20 concepts.
 ///
 
 #pragma once
@@ -19,7 +20,7 @@
 #error "C++11 compiler or better is required"
 #elif _MSC_VER >= 1910
 #error                                                                         \
-    "Please add ` /Zc:__cplusplus` to MSVC compiler options to enforce it conform ISO C++"
+    "Please add `/Zc:__cplusplus` to MSVC compiler options to enforce it conform ISO C++"
 #endif /* MSVC is mad and don't define __cplusplus properly */
 #endif /* __cplusplus < 201103L */
 
@@ -194,7 +195,9 @@
 #ifndef MDBX_CXX20_CONCEPT
 #if defined(DOXYGEN) ||                                                        \
     (defined(__cpp_concepts) && __cpp_concepts >= 201907L &&                   \
-     (!defined(__clang__) || __clang_major__ >= 12))
+     (!defined(__clang__) || (__clang_major__ >= 12 && !defined(__APPLE__)) || \
+      __clang_major__ >=                                                       \
+          /* Hope Apple will fix concepts in AppleClang 14 */ 14))
 #define MDBX_CXX20_CONCEPT(CONCEPT, NAME) CONCEPT NAME
 #else
 #define MDBX_CXX20_CONCEPT(CONCEPT, NAME) typename NAME
@@ -204,7 +207,9 @@
 #ifndef MDBX_ASSERT_CXX20_CONCEPT_SATISFIED
 #if defined(DOXYGEN) ||                                                        \
     (defined(__cpp_concepts) && __cpp_concepts >= 201907L &&                   \
-     (!defined(__clang__) || __clang_major__ >= 12))
+     (!defined(__clang__) || (__clang_major__ >= 12 && !defined(__APPLE__)) || \
+      __clang_major__ >=                                                       \
+          /* Hope Apple will fix concepts in AppleClang 14 */ 14))
 #define MDBX_ASSERT_CXX20_CONCEPT_SATISFIED(CONCEPT, TYPE)                     \
   static_assert(CONCEPT<TYPE>)
 #else
@@ -286,7 +291,8 @@ class cursor;
 class cursor_managed;
 
 #if defined(DOXYGEN) ||                                                        \
-    defined(__cpp_lib_memory_resource) && __cpp_lib_memory_resource >= 201603L
+    (defined(__cpp_lib_memory_resource) &&                                     \
+     __cpp_lib_memory_resource >= 201603L && _GLIBCXX_USE_CXX11_ABI)
 /// \brief Default polymorphic allocator for modern code.
 using polymorphic_allocator = ::std::pmr::string::allocator_type;
 #endif /* __cpp_lib_memory_resource >= 201603L */
@@ -472,34 +478,29 @@ static MDBX_CXX20_CONSTEXPR void *memcpy(void *dest, const void *src,
 
 #if defined(DOXYGEN) ||                                                        \
     (defined(__cpp_concepts) && __cpp_concepts >= 201907L &&                   \
-     (!defined(__clang__) || __clang_major__ >= 12))
+     (!defined(__clang__) || (__clang_major__ >= 12 && !defined(__APPLE__)) || \
+      __clang_major__ >=                                                       \
+          /* Hope Apple will fix concepts in AppleClang 14 */ 14))
 
 template <typename T>
 concept MutableByteProducer = requires(T a, char array[42]) {
-  { a.is_empty() }
-  ->std::same_as<bool>;
-  { a.envisage_result_length() }
-  ->std::same_as<size_t>;
-  { a.write_bytes(&array[0], size_t(42)) }
-  ->std::same_as<char *>;
+  { a.is_empty() } -> std::same_as<bool>;
+  { a.envisage_result_length() } -> std::same_as<size_t>;
+  { a.write_bytes(&array[0], size_t(42)) } -> std::same_as<char *>;
 };
 
 template <typename T>
 concept ImmutableByteProducer = requires(const T &a, char array[42]) {
-  { a.is_empty() }
-  ->std::same_as<bool>;
-  { a.envisage_result_length() }
-  ->std::same_as<size_t>;
-  { a.write_bytes(&array[0], size_t(42)) }
-  ->std::same_as<char *>;
+  { a.is_empty() } -> std::same_as<bool>;
+  { a.envisage_result_length() } -> std::same_as<size_t>;
+  { a.write_bytes(&array[0], size_t(42)) } -> std::same_as<char *>;
 };
 
 template <typename T>
-concept SliceTranscoder =
-    ImmutableByteProducer<T> &&requires(const slice &source, const T &a) {
+concept SliceTranscoder = ImmutableByteProducer<T> &&
+    requires(const slice &source, const T &a) {
   T(source);
-  { a.is_erroneous() }
-  ->std::same_as<bool>;
+  { a.is_erroneous() } -> std::same_as<bool>;
 };
 
 #endif /* __cpp_concepts >= 201907L*/
@@ -3949,7 +3950,7 @@ inline ::std::ostream &operator<<(::std::ostream &out,
 
 //==============================================================================
 //
-// Inline body of the libmdbx C++ API (preliminary draft)
+// Inline body of the libmdbx C++ API
 //
 
 MDBX_CXX11_CONSTEXPR const version_info &get_version() noexcept {

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

@@ -1,9 +1,9 @@
-From ce7b70a572cf77d8f37e5047d5d9c8361b2675ae Mon Sep 17 00:00:00 2001
+From f732fc79456f3b296543ab2625d35eeef2655618 Mon Sep 17 00:00:00 2001
 From: Leonid Yuriev <leo@yuriev.ru>
-Date: Sun, 10 Oct 2021 15:31:40 +0300
+Date: Sun, 24 Oct 2021 20:13:33 +0300
 Subject: [PATCH] package/libmdbx: new package (library/database).
 
-This patch adds libmdbx v0.10.4:
+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.
@@ -103,18 +103,18 @@ 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..326cf57bb6
+index 0000000000..c8b50f9ac3
 --- /dev/null
 +++ b/package/libmdbx/libmdbx.hash
 @@ -0,0 +1,5 @@
 +# Hashes from: https://github.com/erthink/libmdbx/releases/
-+sha256  e11d5339a1e1cc34407898933b62a208936fd761a2cc31e11244d581d1d2b5d0  libmdbx-amalgamated-0.10.4.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..f38e4a533b
+index 0000000000..02d00b1a5a
 --- /dev/null
 +++ b/package/libmdbx/libmdbx.mk
 @@ -0,0 +1,42 @@
@@ -124,7 +124,7 @@ index 0000000000..f38e4a533b
 +#
 +################################################################################
 +
-+LIBMDBX_VERSION = 0.10.4
++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
@@ -161,5 +161,5 @@ index 0000000000..f38e4a533b
 +
 +$(eval $(cmake-package))
 -- 
-2.33.0
+2.33.1
 

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
@@ -264,8 +277,6 @@ static __always_inline memory_order mo_c11_load(enum MDBX_memory_order fence) {
 
 #ifndef __cplusplus
 
-static __inline void mdbx_jitter4testing(bool tiny);
-
 MDBX_MAYBE_UNUSED static __always_inline void
 mdbx_memory_fence(enum MDBX_memory_order order, bool write) {
 #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 */
 }
 
-MDBX_MAYBE_UNUSED static __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;
-}
-
-MDBX_MAYBE_UNUSED static
-#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 */
 
 /*----------------------------------------------------------------------------*/
@@ -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
@@ -1257,6 +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);
@@ -1426,15 +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);
 
-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
-}
-
 #endif /* !__cplusplus */
 
 #define MDBX_IS_ERROR(rc)                                                      \
@@ -1569,10 +1514,11 @@ 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
 

src/mdbx.c++

@@ -2,12 +2,12 @@
 // Copyright (c) 2020-2021, Leonid Yuriev <leo@yuriev.ru>.
 // SPDX-License-Identifier: Apache-2.0
 //
-// Non-inline part of the libmdbx C++ API (preliminary)
+// Non-inline part of the libmdbx C++ API
 //
 
-#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++"
 
@@ -992,7 +992,8 @@ bool from_base64::is_erroneous() const noexcept {
 
 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 */
 

src/osal.c

@@ -1461,8 +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,

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>
@@ -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 */
@@ -735,7 +734,6 @@ MDBX_MAYBE_UNUSED static __inline uintptr_t mdbx_thread_self(void) {
   return (uintptr_t)thunk;
 }
 
-MDBX_MAYBE_UNUSED MDBX_INTERNAL_FUNC void 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);

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 */

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))) {
@@ -280,6 +285,11 @@ bool testcase_hill::run() {
       log_notice("hill: reached %d tree depth & %s sub-tree depth(s)",
                  stat.ms_depth, str.c_str());
     }
+
+    if ((config.params.table_flags & MDBX_DUPSORT) == 0) {
+      if (!check_batch_get())
+        failure("batch-get verification failed");
+    }
   }
 
   while (serial_count > 1) {

test/long_stochastic.sh

@@ -210,6 +210,11 @@ echo "=== use ${db_size_mb}M for DB"
 # 3. Create test-directory in ramfs/tmpfs, i.e. create/format/mount if required
 case ${UNAME} in
   Linux)
+    ulimit -c unlimited
+    if [ "$(cat /proc/sys/kernel/core_pattern)" != "core.%p" ]; then
+      echo "core.%p > /proc/sys/kernel/core_pattern" >&2
+      echo "core.%p" | sudo tee /proc/sys/kernel/core_pattern || true
+    fi
   ;;
 
   FreeBSD)

test/nested.cc

@@ -189,6 +189,26 @@ bool testcase_nested::stochastic_breakable_restart_with_nested(
          (flipcoin() || txn_underutilization_x256(txn_guard.get()) < 42))
     should_continue &= pop_txn();
 
+  if (flipcoin_x3()) {
+    unsigned period;
+    int err = mdbx_env_get_syncperiod(db_guard.get(), &period);
+    if (unlikely(err != MDBX_SUCCESS))
+      failure_perror("mdbx_env_get_syncperiod()", err);
+
+    size_t bytes;
+    err = mdbx_env_get_syncbytes(db_guard.get(), &bytes);
+    if (unlikely(err != MDBX_SUCCESS))
+      failure_perror("mdbx_env_get_syncbytes()", err);
+
+    err = mdbx_env_set_syncperiod(db_guard.get(), period ^ 42);
+    if (unlikely(err != MDBX_SUCCESS) && err != MDBX_BUSY)
+      failure_perror("mdbx_env_set_syncperiod()", err);
+
+    err = mdbx_env_set_syncbytes(db_guard.get(), bytes ^ 42000);
+    if (unlikely(err != MDBX_SUCCESS) && err != MDBX_BUSY)
+      failure_perror("mdbx_env_set_syncbytes()", err);
+  }
+
   if (should_continue)
     while (stack.empty() ||
            (is_nested_txn_available() && flipcoin() && stack.size() < 5))

test/stochastic_small.sh

@@ -210,6 +210,11 @@ echo "=== use ${db_size_mb}M for DB"
 # 3. Create test-directory in ramfs/tmpfs, i.e. create/format/mount if required
 case ${UNAME} in
   Linux)
+    ulimit -c unlimited
+    if [ "$(cat /proc/sys/kernel/core_pattern)" != "core.%p" ]; then
+      echo "core.%p > /proc/sys/kernel/core_pattern" >&2
+      echo "core.%p" | sudo tee /proc/sys/kernel/core_pattern || true
+    fi
   ;;
 
   FreeBSD)

test/test.cc

@@ -164,6 +164,14 @@ void testcase::db_open() {
   if (unlikely(rc != MDBX_SUCCESS))
     failure_perror("mdbx_env_open()", rc);
 
+  rc = mdbx_env_set_syncperiod(db_guard.get(), unsigned(0.042 * 65536));
+  if (unlikely(rc != MDBX_SUCCESS) && rc != MDBX_BUSY)
+    failure_perror("mdbx_env_set_syncperiod()", rc);
+
+  rc = mdbx_env_set_syncbytes(db_guard.get(), INT_MAX / 421);
+  if (unlikely(rc != MDBX_SUCCESS) && rc != MDBX_BUSY)
+    failure_perror("mdbx_env_set_syncbytes()", rc);
+
   log_trace("<< db_open");
 }
 
@@ -641,7 +649,8 @@ 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 {
@@ -715,7 +724,7 @@ 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));
 
@@ -852,11 +861,26 @@ 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 */
   }
 
@@ -881,6 +905,26 @@ 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;
@@ -1050,6 +1094,15 @@ 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)));
@@ -1132,3 +1185,69 @@ bool testcase::speculum_verify() {
   mdbx_cursor_close(cursor);
   return rc;
 }
+
+bool testcase::check_batch_get() {
+  char dump_key[128], dump_value[128];
+  char dump_key_batch[128], dump_value_batch[128];
+
+  MDBX_cursor *cursor;
+  int err = mdbx_cursor_open(txn_guard.get(), dbi, &cursor);
+  if (err != MDBX_SUCCESS)
+    failure_perror("mdbx_cursor_open()", err);
+
+  MDBX_cursor *batch_cursor;
+  err = mdbx_cursor_open(txn_guard.get(), dbi, &batch_cursor);
+  if (err != MDBX_SUCCESS)
+    failure_perror("mdbx_cursor_open()", err);
+
+  MDBX_val pairs[42];
+  size_t count = 0xDeadBeef;
+  err = mdbx_cursor_get_batch(batch_cursor, &count, pairs, ARRAY_LENGTH(pairs),
+                              MDBX_FIRST);
+  bool rc = true;
+  size_t i, n = 0;
+  while (err == MDBX_SUCCESS) {
+    for (i = 0; i < count; i += 2) {
+      mdbx::slice key, value;
+      int err2 = mdbx_cursor_get(cursor, &key, &value, MDBX_NEXT);
+      if (err2 != MDBX_SUCCESS)
+        failure_perror("mdbx_cursor_open()", err2);
+      if (key != pairs[i] || value != pairs[i + 1]) {
+        log_error(
+            "batch-get pair mismatch %zu/%zu: sequential{%s, %s} != "
+            "batch{%s, %s}",
+            n + i / 2, i, mdbx_dump_val(&key, dump_key, sizeof(dump_key)),
+            mdbx_dump_val(&value, dump_value, sizeof(dump_value)),
+            mdbx_dump_val(&pairs[i], dump_key_batch, sizeof(dump_key_batch)),
+            mdbx_dump_val(&pairs[i + 1], dump_value_batch,
+                          sizeof(dump_value_batch)));
+        rc = false;
+      }
+    }
+    n += i / 2;
+    err = mdbx_cursor_get_batch(batch_cursor, &count, pairs,
+                                ARRAY_LENGTH(pairs), MDBX_NEXT);
+  }
+  if (err != MDBX_NOTFOUND)
+    failure_perror("mdbx_cursor_get_batch()", err);
+
+  err = mdbx_cursor_eof(batch_cursor);
+  if (err != MDBX_RESULT_TRUE) {
+    log_error("batch-get %s cursor not-eof %d", "batch", err);
+    rc = false;
+  }
+  err = mdbx_cursor_on_last(batch_cursor);
+  if (err != MDBX_RESULT_TRUE) {
+    log_error("batch-get %s cursor not-on-last %d", "batch", err);
+    rc = false;
+  }
+
+  err = mdbx_cursor_on_last(cursor);
+  if (err != MDBX_RESULT_TRUE) {
+    log_error("batch-get %s cursor not-on-last %d", "checked", err);
+    rc = false;
+  }
+  mdbx_cursor_close(cursor);
+  mdbx_cursor_close(batch_cursor);
+  return rc;
+}

test/test.h

@@ -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,
@@ -227,6 +227,7 @@ protected:
                const MDBX_val &v) const;
 
   bool speculum_verify();
+  bool check_batch_get();
   int insert(const keygen::buffer &akey, const keygen::buffer &adata,
              MDBX_put_flags_t flags);
   int replace(const keygen::buffer &akey, const keygen::buffer &new_value,