mdbx: release v0.11.6

The stable release with the complete workaround for an incoherence flaw of Linux unified page/buffer cache.
Nonetheless the cause for this trouble may be an issue of Intel CPU cache/MESI.
See [issue#269](https://github.com/erthink/libmdbx/issues/269) for more information.

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

 - [David Bouyssié](https://github.com/david-bouyssie) for [Scala bindings](https://github.com/david-bouyssie/mdbx4s).
 - [Michelangelo Riccobene](https://github.com/mriccobene) for reporting and testing.

Fixes:
------

 - [Added complete workaround](https://github.com/erthink/libmdbx/issues/269) for an incoherence flaw of Linux unified page/buffer cache.
 - [Fixed](https://github.com/erthink/libmdbx/issues/272) cursor reusing for read-only transactions.
 - Fixed copy&paste typo inside `mdbx::cursor::find_multivalue()`.

Minors:
-------

 - Minor refine C++ API for convenience.
 - Minor internals refines.
 - Added `lib-static` and `lib-shared` targets for make.
 - Added minor workaround for AppleClang 13.3 bug.
 - Clarified error messages of a signature/version mismatch.

Signed-off-by: Леонид Юрьев (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://paypal.me/erthink', 'https://www.blockchain.com/en/eth/address/0x19291d8658f762f3baceae1700c0b9466572ceab', 'https://www.blockchain.com/en/btc/address/152u2KXNWWGHQS3qiBEoQaveWyPvaSWYGC']
+custom: ['https://www.blockchain.com/en/eth/address/0x19291d8658f762f3baceae1700c0b9466572ceab', 'https://www.blockchain.com/en/btc/address/152u2KXNWWGHQS3qiBEoQaveWyPvaSWYGC']

.github/actions/spelling/expect.txt

@@ -1,4 +1,3 @@
-[200~Alexey
 aarch
 abcdef
 abf
@@ -22,6 +21,7 @@ Akhunov
 Akula
 Aleksey
 alevel
+Alexey
 alexey
 Alfke
 alignas
@@ -103,6 +103,8 @@ biarch
 bibtex
 BIGDATA
 bigdata
+Binance
+binance
 bindir
 binfmt
 binutils
@@ -206,6 +208,8 @@ condattr
 condpair
 config
 constexpr
+constmeta
+coprs
 copyable
 copydetails
 copydoc
@@ -385,6 +389,7 @@ DVAL
 DVI
 dw
 DWORD
+dwords
 dxb
 dxbfile
 dylib
@@ -508,6 +513,7 @@ FCXX
 fd
 fdatasync
 featuredarticles
+fedorainfracloud
 fedotov
 FEEDNAME
 feof
@@ -662,9 +668,11 @@ hlp
 HOfynt
 hostid
 HOSTUUID
+hotfix
 hpp
 hppa
 hpux
+href
 hrows
 hsr
 htags
@@ -678,9 +686,11 @@ Hubert's
 hxx
 hyc
 hyperlink
+hypotetic
 IBERTY
 IBMC
 ibmxl
+idempotence
 idl
 idx
 ieeetr
@@ -754,6 +764,7 @@ IRWXU
 isa
 isatty
 ISDIR
+iset
 ISOC
 isode
 isprint
@@ -783,6 +794,7 @@ jgamble
 jmp
 jpg
 json
+kaiwetlesen
 kbuf
 Kerollmops
 kerr
@@ -812,6 +824,7 @@ Kuntze
 kurt
 kuznik
 kval
+kwetlesen
 Lanfranchi
 largedata
 largepage
@@ -827,7 +840,11 @@ lcklist
 LDAP
 LDFLAGS
 leafnode
+Ledgerwatch
+ledgerwatch
 leetal
+Leier
+leisim
 len
 lenfast
 Lenovo
@@ -1227,6 +1244,7 @@ oublock
 OUTOFMEMORY
 ov
 overf
+overrided
 ovpage
 pageable
 pagecache
@@ -1477,6 +1495,7 @@ rpath
 rpb
 rpcc
 rpid
+RPMs
 rqest
 rr
 RRF
@@ -1921,6 +1940,7 @@ wdm
 webassembly
 webclient
 WERROR
+Wetlesen
 WEXITSTATUS
 WEXTRA
 whitelist

ChangeLog.md

@@ -17,6 +17,61 @@ ChangeLog
  - Packages for [Astra Linux](https://astralinux.ru/), [ALT Linux](https://www.altlinux.org/), [ROSA Linux](https://www.rosalinux.ru/), etc.
 
 
+## v0.11.6 (scheduled for 2022-03-24)
+
+The stable release with the complete workaround for an incoherence flaw of Linux unified page/buffer cache.
+Nonetheless the cause for this trouble may be an issue of Intel CPU cache/MESI.
+See [issue#269](https://github.com/erthink/libmdbx/issues/269) for more information.
+
+Acknowledgements:
+
+ - [David Bouyssié](https://github.com/david-bouyssie) for [Scala bindings](https://github.com/david-bouyssie/mdbx4s).
+ - [Michelangelo Riccobene](https://github.com/mriccobene) for reporting and testing.
+
+Fixes:
+
+ - [Added complete workaround](https://github.com/erthink/libmdbx/issues/269) for an incoherence flaw of Linux unified page/buffer cache.
+ - [Fixed](https://github.com/erthink/libmdbx/issues/272) cursor reusing for read-only transactions.
+ - Fixed copy&paste typo inside `mdbx::cursor::find_multivalue()`.
+
+Minors:
+
+ - Minor refine C++ API for convenience.
+ - Minor internals refines.
+ - Added `lib-static` and `lib-shared` targets for make.
+ - Added minor workaround for AppleClang 13.3 bug.
+ - Clarified error messages of a signature/version mismatch.
+
+
+## v0.11.5 at 2022-02-23
+
+The release with the temporary hotfix for a flaw of Linux unified page/buffer cache.
+See [issue#269](https://github.com/erthink/libmdbx/issues/269) for more information.
+
+Acknowledgements:
+
+ - [Simon Leier](https://github.com/leisim) for reporting and testing.
+ - [Kai Wetlesen](https://github.com/kaiwetlesen) for [RPMs](http://copr.fedorainfracloud.org/coprs/kwetlesen/libmdbx/).
+ - [Tullio Canepa](https://github.com/canepat) for reporting C++ API issue and contributing.
+
+Fixes:
+
+ - [Added hotfix](https://github.com/erthink/libmdbx/issues/269) for a flaw of Linux unified page/buffer cache.
+ - [Fixed/Reworked](https://github.com/erthink/libmdbx/pull/270) move-assignment operators for "managed" classes of C++ API.
+ - Fixed potential `SIGSEGV` while open DB with overrided non-default page size.
+ - [Made](https://github.com/erthink/libmdbx/issues/267) `mdbx_env_open()` idempotence in failure cases.
+ - Refined/Fixed pages reservation inside `mdbx_update_gc()` to avoid non-reclamation in a rare cases.
+ - Fixed typo in a retained space calculation for the hsr-callback.
+
+Minors:
+
+ - Reworked functions for meta-pages, split-off non-volatile.
+ - Disentangled C11-atomic fences/barriers and pure-functions (with `__attribute__((__pure__))`) to avoid compiler misoptimization.
+ - Fixed hypotetic unaligned access to 64-bit dwords on ARM with `__ARM_FEATURE_UNALIGNED` defined.
+ - Reasonable paranoia that makes clarity for code readers.
+ - Minor fixes Doxygen references, comments, descriptions, etc.
+
+
 ## v0.11.4 at 2022-02-02
 
 The stable release with fixes for large and huge databases sized of 4..128 TiB.

GNUmakefile

@@ -59,8 +59,8 @@ 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 check_buildflags_tag
-.PHONY: install-strip install-no-strip strip libmdbx mdbx show-options
+.PHONY: all help options lib libs tools clean install uninstall check_buildflags_tag
+.PHONY: install-strip install-no-strip strip libmdbx mdbx show-options lib-static lib-shared
 
 ifeq ("$(origin V)", "command line")
   MDBX_BUILD_VERBOSE := $(V)
@@ -85,7 +85,7 @@ help:
 	@echo "  make all                 - build libraries and tools"
 	@echo "  make help                - print this help"
 	@echo "  make options             - list build options"
-	@echo "  make lib                 - build libraries"
+	@echo "  make lib                 - build libraries, also lib-static and lib-shared"
 	@echo "  make tools               - built tools"
 	@echo "  make clean               "
 	@echo "  make install             "
@@ -172,7 +172,7 @@ else
 endif
 #< dist-cutoff-end
 
-lib libmdbx mdbx: libmdbx.a libmdbx.$(SO_SUFFIX)
+lib libs libmdbx mdbx: libmdbx.a libmdbx.$(SO_SUFFIX)
 
 tools: $(TOOLS)
 
@@ -196,11 +196,11 @@ check_buildflags_tag:
 
 buildflags.tag: check_buildflags_tag
 
-libmdbx.a: mdbx-static.o mdbx++-static.o
+lib-static libmdbx.a: mdbx-static.o mdbx++-static.o
 	@echo '  AR $@'
 	$(QUIET)$(AR) rcs $@ $? $(HUSH)
 
-libmdbx.$(SO_SUFFIX): mdbx-dylib.o mdbx++-dylib.o
+lib-shared libmdbx.$(SO_SUFFIX): mdbx-dylib.o mdbx++-dylib.o
 	@echo '  LD $@'
 	$(QUIET)$(CXX) $(CXXFLAGS) $^ -pthread -shared $(LDFLAGS) $(LIBS) -o $@
 

Makefile

@@ -3,7 +3,8 @@
 all help options \
 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 \
+lib libs lib-static lib-shared \
+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 smoke smoke-fault smoke-singleprocess \
 test-asan test-leak test-singleprocess test-ubsan test-valgrind:

README.md

@@ -515,7 +515,7 @@ Another ways to build is potentially possible but not supported and will not.
 The `CMakeLists.txt` or `GNUMakefile` scripts will probably need to be modified accordingly.
 Using other methods do not forget to add the `ntdll.lib` to linking.
 
-It should be noted that in _libmdbx_ was efforts to resolve
+It should be noted that in _libmdbx_ was efforts to avoid
 runtime dependencies from CRT and other MSVC libraries.
 For this is enough to pass the `-DMDBX_WITHOUT_MSVC_CRT:BOOL=ON` option
 during configure by CMake.
@@ -571,6 +571,7 @@ Bindings
 
 | Runtime |  Repo  | Author |
 | ------- | ------ | ------ |
+| Scala   | [mdbx4s](https://github.com/david-bouyssie/mdbx4s) | [David Bouyssié](https://github.com/david-bouyssie) |
 | Haskell | [libmdbx-hs](https://hackage.haskell.org/package/libmdbx) | [Francisco Vallarino](https://github.com/fjvallarino) |
 | NodeJS, [Deno](https://deno.land/) | [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) |
@@ -731,4 +732,4 @@ syscall and by scanning the data directory.
 
 --------------------------------------------------------------------------------
 
-#### This is a mirror of the origin repository that was moved to [abf.io](https://abf.io/erthink/) because of discriminatory restrictions for Russian Crimea.
+#### This is a mirror of the origin repository that was moved to [gitflic.ru](https://gitflic.ru/project/erthink/libmdbx) because of discriminatory restrictions for Russian Crimea.

appveyor.yml

@@ -1,4 +1,4 @@
-version: 0.11.4.{build}
+version: 0.11.6.{build}
 
 environment:
   matrix:

mdbx.h

@@ -784,36 +784,51 @@ enum MDBX_constants {
  * \note Most of debug feature enabled only when libmdbx builded with
  * \ref MDBX_DEBUG build option. @{ */
 
-/** Log level (requires build libmdbx with \ref MDBX_DEBUG option) */
+/** Log level
+ * \note Levels detailed than (great than) \ref MDBX_LOG_NOTICE
+ * requires build libmdbx with \ref MDBX_DEBUG option. */
 enum MDBX_log_level_t {
-  /** Critical conditions, i.e. assertion failures */
+  /** Critical conditions, i.e. assertion failures.
+   * \note libmdbx always produces such messages regardless
+   * of \ref MDBX_DEBUG build option. */
   MDBX_LOG_FATAL = 0,
 
-  /** Enables logging for error conditions and \ref MDBX_LOG_FATAL */
+  /** Enables logging for error conditions
+   * and \ref MDBX_LOG_FATAL.
+   * \note libmdbx always produces such messages regardless
+   * of \ref MDBX_DEBUG build option. */
   MDBX_LOG_ERROR = 1,
 
-  /** Enables logging for warning conditions and \ref MDBX_LOG_ERROR ...
-      \ref MDBX_LOG_FATAL */
+  /** Enables logging for warning conditions
+   * and \ref MDBX_LOG_ERROR ... \ref MDBX_LOG_FATAL.
+   * \note libmdbx always produces such messages regardless
+   * of \ref MDBX_DEBUG build option. */
   MDBX_LOG_WARN = 2,
 
-  /** Enables logging for normal but significant condition and
-      \ref MDBX_LOG_WARN ... \ref MDBX_LOG_FATAL */
+  /** Enables logging for normal but significant condition
+   * and \ref MDBX_LOG_WARN ... \ref MDBX_LOG_FATAL.
+   * \note libmdbx always produces such messages regardless
+   * of \ref MDBX_DEBUG build option. */
   MDBX_LOG_NOTICE = 3,
 
-  /** Enables logging for verbose informational and \ref MDBX_LOG_NOTICE ...
-      \ref MDBX_LOG_FATAL */
+  /** Enables logging for verbose informational
+   * and \ref MDBX_LOG_NOTICE ... \ref MDBX_LOG_FATAL.
+   * \note Requires build libmdbx with \ref MDBX_DEBUG option. */
   MDBX_LOG_VERBOSE = 4,
 
-  /** Enables logging for debug-level messages and \ref MDBX_LOG_VERBOSE ...
-      \ref MDBX_LOG_FATAL */
+  /** Enables logging for debug-level messages
+   * and \ref MDBX_LOG_VERBOSE ... \ref MDBX_LOG_FATAL.
+   * \note Requires build libmdbx with \ref MDBX_DEBUG option. */
   MDBX_LOG_DEBUG = 5,
 
-  /** Enables logging for trace debug-level messages and \ref MDBX_LOG_DEBUG ...
-      \ref MDBX_LOG_FATAL */
+  /** Enables logging for trace debug-level messages
+   * and \ref MDBX_LOG_DEBUG ... \ref MDBX_LOG_FATAL.
+   * \note Requires build libmdbx with \ref MDBX_DEBUG option. */
   MDBX_LOG_TRACE = 6,
 
   /** Enables extra debug-level messages (dump pgno lists)
-      and all other log-messages */
+   * and all other log-messages.
+   * \note Requires build libmdbx with \ref MDBX_DEBUG option. */
   MDBX_LOG_EXTRA = 7,
 
 #ifdef ENABLE_UBSAN
@@ -836,30 +851,36 @@ enum MDBX_debug_flags_t {
   MDBX_DBG_NONE = 0,
 
   /** Enable assertion checks.
-   * Requires build with \ref MDBX_DEBUG > 0 */
+   * \note Always enabled for builds with `MDBX_FORCE_ASSERTIONS` option,
+   * otherwise requires build with \ref MDBX_DEBUG > 0 */
   MDBX_DBG_ASSERT = 1,
 
   /** Enable pages usage audit at commit transactions.
-   * Requires build with \ref MDBX_DEBUG > 0 */
+   * \note Requires build with \ref MDBX_DEBUG > 0 */
   MDBX_DBG_AUDIT = 2,
 
   /** Enable small random delays in critical points.
-   * Requires build with \ref MDBX_DEBUG > 0 */
+   * \note Requires build with \ref MDBX_DEBUG > 0 */
   MDBX_DBG_JITTER = 4,
 
   /** Include or not meta-pages in coredump files.
-   * May affect performance in \ref MDBX_WRITEMAP mode */
+   * \note May affect performance in \ref MDBX_WRITEMAP mode */
   MDBX_DBG_DUMP = 8,
 
   /** Allow multi-opening environment(s) */
   MDBX_DBG_LEGACY_MULTIOPEN = 16,
 
-  /** Allow read and write transactions overlapping for the same thread */
+  /** Allow read and write transactions overlapping for the same thread. */
   MDBX_DBG_LEGACY_OVERLAP = 32,
 
+  /** Don't auto-upgrade format signature.
+   * \note However a new write transactions will use and store
+   * the last signature regardless this flag */
+  MDBX_DBG_DONT_UPGRADE = 64,
+
 #ifdef ENABLE_UBSAN
   MDBX_DBG_MAX = ((unsigned)MDBX_LOG_MAX) << 16 |
-                 63 /* avoid UBSAN false-positive trap by a tests */,
+                 127 /* avoid UBSAN false-positive trap by a tests */,
 #endif /* ENABLE_UBSAN */
 
   /** for mdbx_setup_debug() only: Don't change current settings */
@@ -4898,7 +4919,9 @@ LIBMDBX_API int mdbx_thread_unregister(const MDBX_env *env);
  * is not enough space in the database (i.e. before increasing the database size
  * or before \ref MDBX_MAP_FULL error) and thus can be used to resolve issues
  * with a "long-lived" read transactions.
- * \see long-lived-read
+ * \see mdbx_env_set_hsr()
+ * \see mdbx_env_get_hsr()
+ * \see <a href="intro.html#long-lived-read">Long-lived read transactions</a>
  *
  * Using this callback you can choose how to resolve the situation:
  *   - abort the write transaction with an error;
@@ -4956,8 +4979,6 @@ LIBMDBX_API int mdbx_thread_unregister(const MDBX_env *env);
  *
  * \retval 2 or great  The reader process was terminated or killed,
  *                     and libmdbx should entirely reset reader registration.
- *
- * \see mdbx_env_set_hsr() \see mdbx_env_get_hsr()
  */
 typedef int(MDBX_hsr_func)(const MDBX_env *env, const MDBX_txn *txn,
                            mdbx_pid_t pid, mdbx_tid_t tid, uint64_t laggard,
@@ -4971,8 +4992,9 @@ typedef int(MDBX_hsr_func)(const MDBX_env *env, const MDBX_txn *txn,
  * The callback will only be triggered when the database is full due to a
  * reader(s) prevents the old data from being recycled.
  *
+ * \see MDBX_hsr_func
  * \see mdbx_env_get_hsr()
- * \see long-lived-read
+ * \see <a href="intro.html#long-lived-read">Long-lived read transactions</a>
  *
  * \param [in] env             An environment handle returned
  *                             by \ref mdbx_env_create().
@@ -4985,7 +5007,9 @@ LIBMDBX_API int mdbx_env_set_hsr(MDBX_env *env, MDBX_hsr_func *hsr_callback);
 /** \brief Gets current Handle-Slow-Readers callback used to resolve database
  * full/overflow issue due to a reader(s) which prevents the old data from being
  * recycled.
+ * \see MDBX_hsr_func
  * \see mdbx_env_set_hsr()
+ * \see <a href="intro.html#long-lived-read">Long-lived read transactions</a>
  *
  * \param [in] env   An environment handle returned by \ref mdbx_env_create().
  *

mdbx.h++

@@ -2960,6 +2960,18 @@ public:
     inline geometry &make_fixed(intptr_t size) noexcept;
     inline geometry &make_dynamic(intptr_t lower = minimal_value,
                                   intptr_t upper = maximal_value) noexcept;
+    MDBX_CXX11_CONSTEXPR geometry() noexcept {}
+    MDBX_CXX11_CONSTEXPR
+    geometry(const geometry &) noexcept = default;
+    MDBX_CXX11_CONSTEXPR geometry(intptr_t size_lower,
+                                  intptr_t size_now = default_value,
+                                  intptr_t size_upper = maximal_value,
+                                  intptr_t growth_step = default_value,
+                                  intptr_t shrink_threshold = default_value,
+                                  intptr_t pagesize = default_value) noexcept
+        : size_lower(size_lower), size_now(size_now), size_upper(size_upper),
+          growth_step(growth_step), shrink_threshold(shrink_threshold),
+          pagesize(pagesize) {}
   };
 
   /// \brief Operation mode.
@@ -2984,6 +2996,10 @@ public:
     /// \copydoc MDBX_COALESCE
     bool coalesce{false};
     MDBX_CXX11_CONSTEXPR reclaiming_options() noexcept {}
+    MDBX_CXX11_CONSTEXPR
+    reclaiming_options(const reclaiming_options &) noexcept = default;
+    MDBX_CXX14_CONSTEXPR reclaiming_options &
+    operator=(const reclaiming_options &) noexcept = default;
     reclaiming_options(MDBX_env_flags_t) noexcept;
   };
 
@@ -2999,6 +3015,10 @@ public:
     /// \copydoc MDBX_NOMEMINIT
     bool disable_clear_memory{false};
     MDBX_CXX11_CONSTEXPR operate_options() noexcept {}
+    MDBX_CXX11_CONSTEXPR
+    operate_options(const operate_options &) noexcept = default;
+    MDBX_CXX14_CONSTEXPR operate_options &
+    operator=(const operate_options &) noexcept = default;
     operate_options(MDBX_env_flags_t) noexcept;
   };
 
@@ -3016,6 +3036,19 @@ public:
     env::operate_options options;
 
     MDBX_CXX11_CONSTEXPR operate_parameters() noexcept {}
+    MDBX_CXX11_CONSTEXPR
+    operate_parameters(
+        const unsigned max_maps, const unsigned max_readers = 0,
+        const env::mode mode = env::mode::write_mapped_io,
+        env::durability durability = env::durability::robust_synchronous,
+        const env::reclaiming_options &reclaiming = env::reclaiming_options(),
+        const env::operate_options &options = env::operate_options()) noexcept
+        : max_maps(max_maps), max_readers(max_readers), mode(mode),
+          durability(durability), reclaiming(reclaiming), options(options) {}
+    MDBX_CXX11_CONSTEXPR
+    operate_parameters(const operate_parameters &) noexcept = default;
+    MDBX_CXX14_CONSTEXPR operate_parameters &
+    operator=(const operate_parameters &) noexcept = default;
     MDBX_env_flags_t
     make_flags(bool accede = true, ///< \copydoc MDBX_ACCEDE
                bool use_subdirectory =
@@ -3027,7 +3060,6 @@ public:
     reclaiming_from_flags(MDBX_env_flags_t flags) noexcept;
     inline static env::operate_options
     options_from_flags(MDBX_env_flags_t flags) noexcept;
-    operate_parameters(const env &);
   };
 
   /// \brief Returns current operation parameters.
@@ -3423,6 +3455,8 @@ public:
     env::geometry geometry;
     mdbx_mode_t file_mode_bits{0640};
     bool use_subdirectory{false};
+    MDBX_CXX11_CONSTEXPR create_parameters() noexcept = default;
+    create_parameters(const create_parameters &) noexcept = default;
   };
 
   /// \brief Create new or open existing database.
@@ -3453,7 +3487,15 @@ public:
   void close(bool dont_sync = false);
 
   env_managed(env_managed &&) = default;
-  env_managed &operator=(env_managed &&) = default;
+  env_managed &operator=(env_managed &&other) {
+    if (MDBX_UNLIKELY(handle_))
+      MDBX_CXX20_UNLIKELY {
+        assert(handle_ != other.handle_);
+        close();
+      }
+    inherited::operator=(std::move(other));
+    return *this;
+  }
   env_managed(const env_managed &) = delete;
   env_managed &operator=(const env_managed &) = delete;
   virtual ~env_managed() noexcept;
@@ -3744,7 +3786,15 @@ class LIBMDBX_API_TYPE txn_managed : public txn {
 public:
   MDBX_CXX11_CONSTEXPR txn_managed() noexcept = default;
   txn_managed(txn_managed &&) = default;
-  txn_managed &operator=(txn_managed &&) = default;
+  txn_managed &operator=(txn_managed &&other) {
+    if (MDBX_UNLIKELY(handle_))
+      MDBX_CXX20_UNLIKELY {
+        assert(handle_ != other.handle_);
+        abort();
+      }
+    inherited::operator=(std::move(other));
+    return *this;
+  }
   txn_managed(const txn_managed &) = delete;
   txn_managed &operator=(const txn_managed &) = delete;
   ~txn_managed() noexcept;
@@ -3939,7 +3989,16 @@ public:
   void close();
 
   cursor_managed(cursor_managed &&) = default;
-  cursor_managed &operator=(cursor_managed &&) = default;
+  cursor_managed &operator=(cursor_managed &&other) {
+    if (MDBX_UNLIKELY(handle_))
+      MDBX_CXX20_UNLIKELY {
+        assert(handle_ != other.handle_);
+        close();
+      }
+    inherited::operator=(std::move(other));
+    return *this;
+  }
+
   cursor_managed(const cursor_managed &) = delete;
   cursor_managed &operator=(const cursor_managed &) = delete;
   ~cursor_managed() noexcept { ::mdbx_cursor_close(handle_); }
@@ -4738,7 +4797,12 @@ inline size_t env::limits::transaction_size_max(intptr_t pagesize) {
 }
 
 inline env::operate_parameters env::get_operation_parameters() const {
-  return env::operate_parameters(*this);
+  const auto flags = get_flags();
+  return operate_parameters(max_maps(), max_readers(),
+                            operate_parameters::mode_from_flags(flags),
+                            operate_parameters::durability_from_flags(flags),
+                            operate_parameters::reclaiming_from_flags(flags),
+                            operate_parameters::options_from_flags(flags));
 }
 
 inline env::mode env::get_mode() const {
@@ -5603,7 +5667,7 @@ inline cursor::move_result cursor::move(move_operation operation,
 inline cursor::move_result cursor::find_multivalue(const slice &key,
                                                    const slice &value,
                                                    bool throw_notfound) {
-  return move(key_exact, key, value, throw_notfound);
+  return move(multi_find_pair, key, value, throw_notfound);
 }
 
 inline cursor::move_result cursor::lower_bound_multivalue(const slice &key,
@@ -5794,7 +5858,7 @@ inline bool cursor::erase(const slice &key, bool whole_multivalue) {
 
 inline bool cursor::erase(const slice &key, const slice &value) {
   move_result data = find_multivalue(key, value, false);
-  return data.done ? erase() : data.done;
+  return data.done && erase();
 }
 
 } // namespace mdbx

src/bits.md

@@ -4,7 +4,7 @@ N |   MASK  | ENV       | TXN          | DB       | PUT       | DBI        | NOD
 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     |         |
+4 |0000 0010|ALLOC_FAKE |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 |         |          |         |

src/internals.h

@@ -445,7 +445,7 @@ typedef struct MDBX_meta {
 #define MDBX_DATASIGN_WEAK 1u
 #define SIGN_IS_STEADY(sign) ((sign) > MDBX_DATASIGN_WEAK)
 #define META_IS_STEADY(meta)                                                   \
-  SIGN_IS_STEADY(unaligned_peek_u64(4, (meta)->mm_datasync_sign))
+  SIGN_IS_STEADY(unaligned_peek_u64_volatile(4, (meta)->mm_datasync_sign))
   uint32_t mm_datasync_sign[2];
 
   /* txnid that committed this page, the second of a two-phase-update pair */
@@ -945,6 +945,7 @@ struct MDBX_txn {
   size_t mt_owner; /* thread ID that owns this transaction */
   MDBX_canary mt_canary;
   void *mt_userctx; /* User-settable context */
+  MDBX_cursor **mt_cursors;
 
   union {
     struct {
@@ -953,7 +954,6 @@ struct MDBX_txn {
     } to;
     struct {
       /* In write txns, array of cursors for each DB */
-      MDBX_cursor **cursors;
       pgno_t *reclaimed_pglist; /* Reclaimed GC pages */
       txnid_t last_reclaimed;   /* ID of last used record */
 #if MDBX_ENABLE_REFUND
@@ -1222,25 +1222,21 @@ MDBX_INTERNAL_FUNC void mdbx_debug_log_va(int level, const char *function,
                                           int line, const char *fmt,
                                           va_list args);
 
-#define mdbx_log_enabled(msg) unlikely(msg <= mdbx_loglevel)
-
 #if MDBX_DEBUG
-
-#define mdbx_assert_enabled() unlikely(mdbx_runtime_flags &MDBX_DBG_ASSERT)
-
-#define mdbx_audit_enabled() unlikely(mdbx_runtime_flags &MDBX_DBG_AUDIT)
-
+#define mdbx_log_enabled(msg) unlikely(msg <= mdbx_loglevel)
+#define mdbx_audit_enabled() unlikely((mdbx_runtime_flags & MDBX_DBG_AUDIT))
 #else /* MDBX_DEBUG */
-
+#define mdbx_log_enabled(msg) (msg < MDBX_LOG_VERBOSE && msg <= mdbx_loglevel)
 #define mdbx_audit_enabled() (0)
+#endif /* MDBX_DEBUG */
 
-#if !defined(NDEBUG) || MDBX_FORCE_ASSERTIONS
+#if MDBX_FORCE_ASSERTIONS
 #define mdbx_assert_enabled() (1)
+#elif MDBX_DEBUG
+#define mdbx_assert_enabled() likely((mdbx_runtime_flags & MDBX_DBG_ASSERT))
 #else
 #define mdbx_assert_enabled() (0)
-#endif /* NDEBUG */
-
-#endif /* MDBX_DEBUG */
+#endif /* assertions */
 
 #if !MDBX_DEBUG && defined(__ANDROID_API__)
 #define mdbx_assert_fail(env, msg, func, line)                                 \
@@ -1252,33 +1248,33 @@ void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *func,
 
 #define mdbx_debug_extra(fmt, ...)                                             \
   do {                                                                         \
-    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_EXTRA))                        \
+    if (mdbx_log_enabled(MDBX_LOG_EXTRA))                                      \
       mdbx_debug_log(MDBX_LOG_EXTRA, __func__, __LINE__, fmt, __VA_ARGS__);    \
   } while (0)
 
 #define mdbx_debug_extra_print(fmt, ...)                                       \
   do {                                                                         \
-    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_EXTRA))                        \
+    if (mdbx_log_enabled(MDBX_LOG_EXTRA))                                      \
       mdbx_debug_log(MDBX_LOG_EXTRA, NULL, 0, fmt, __VA_ARGS__);               \
   } while (0)
 
 #define mdbx_trace(fmt, ...)                                                   \
   do {                                                                         \
-    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_TRACE))                        \
+    if (mdbx_log_enabled(MDBX_LOG_TRACE))                                      \
       mdbx_debug_log(MDBX_LOG_TRACE, __func__, __LINE__, fmt "\n",             \
                      __VA_ARGS__);                                             \
   } while (0)
 
 #define mdbx_debug(fmt, ...)                                                   \
   do {                                                                         \
-    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_DEBUG))                        \
+    if (mdbx_log_enabled(MDBX_LOG_DEBUG))                                      \
       mdbx_debug_log(MDBX_LOG_DEBUG, __func__, __LINE__, fmt "\n",             \
                      __VA_ARGS__);                                             \
   } while (0)
 
 #define mdbx_verbose(fmt, ...)                                                 \
   do {                                                                         \
-    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_VERBOSE))                      \
+    if (mdbx_log_enabled(MDBX_LOG_VERBOSE))                                    \
       mdbx_debug_log(MDBX_LOG_VERBOSE, __func__, __LINE__, fmt "\n",           \
                      __VA_ARGS__);                                             \
   } while (0)

src/man1/mdbx_chk.1

@@ -1,6 +1,6 @@
 .\" Copyright 2015-2022 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_CHK 1 "2022-02-02" "MDBX 0.11.4"
+.TH MDBX_CHK 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_chk \- MDBX checking tool
 .SH SYNOPSIS

src/man1/mdbx_copy.1

@@ -2,7 +2,7 @@
 .\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_COPY 1 "2022-02-02" "MDBX 0.11.4"
+.TH MDBX_COPY 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_copy \- MDBX environment copy tool
 .SH SYNOPSIS

src/man1/mdbx_drop.1

@@ -1,7 +1,7 @@
 .\" Copyright 2021-2022 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2014-2021 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_DROP 1 "2022-02-02" "MDBX 0.11.4"
+.TH MDBX_DROP 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_drop \- MDBX database delete tool
 .SH SYNOPSIS

src/man1/mdbx_dump.1

@@ -2,7 +2,7 @@
 .\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_DUMP 1 "2022-02-02" "MDBX 0.11.4"
+.TH MDBX_DUMP 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_dump \- MDBX environment export tool
 .SH SYNOPSIS

src/man1/mdbx_load.1

@@ -2,7 +2,7 @@
 .\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_LOAD 1 "2022-02-02" "MDBX 0.11.4"
+.TH MDBX_LOAD 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_load \- MDBX environment import tool
 .SH SYNOPSIS

src/man1/mdbx_stat.1

@@ -2,7 +2,7 @@
 .\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_STAT 1 "2022-02-02" "MDBX 0.11.4"
+.TH MDBX_STAT 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_stat \- MDBX environment status tool
 .SH SYNOPSIS

src/mdbx.c++

@@ -1234,21 +1234,12 @@ env::operate_options::operate_options(MDBX_env_flags_t flags) noexcept
       disable_readahead((flags & MDBX_NORDAHEAD) ? true : false),
       disable_clear_memory((flags & MDBX_NOMEMINIT) ? true : false) {}
 
-env::operate_parameters::operate_parameters(const env &env)
-    : max_maps(env.max_maps()), max_readers(env.max_readers()) {
-  const auto flags = env.get_flags();
-  mode = mode_from_flags(flags);
-  durability = durability_from_flags(flags);
-  reclaiming = reclaiming_from_flags(flags);
-  options = options_from_flags(flags);
-}
-
 bool env::is_pristine() const {
   return get_stat().ms_mod_txnid == 0 &&
          get_info().mi_recent_txnid == INITIAL_TXNID;
 }
 
-bool env::is_empty() const { return get_stat().ms_branch_pages == 0; }
+bool env::is_empty() const { return get_stat().ms_leaf_pages == 0; }
 
 #ifdef MDBX_STD_FILESYSTEM_PATH
 env &env::copy(const ::std::filesystem::path &destination, bool compactify,

src/mdbx_chk.c

@@ -935,8 +935,8 @@ static void usage(char *prog) {
   exit(EXIT_INTERRUPTED);
 }
 
-static __inline bool meta_ot(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
-                             uint64_t sign_b, const bool wanna_steady) {
+static bool meta_ot(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
+                    uint64_t sign_b, const bool wanna_steady) {
   if (txn_a == txn_b)
     return SIGN_IS_STEADY(sign_b);
 
@@ -946,8 +946,8 @@ static __inline bool meta_ot(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
   return txn_a < txn_b;
 }
 
-static __inline bool meta_eq(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
-                             uint64_t sign_b) {
+static bool meta_eq(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
+                    uint64_t sign_b) {
   if (!txn_a || txn_a != txn_b)
     return false;
 
@@ -957,7 +957,7 @@ static __inline bool meta_eq(txnid_t txn_a, uint64_t sign_a, txnid_t txn_b,
   return true;
 }
 
-static __inline int meta_recent(const bool wanna_steady) {
+static int meta_recent(const bool wanna_steady) {
   if (meta_ot(envinfo.mi_meta0_txnid, envinfo.mi_meta0_sign,
               envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign, wanna_steady))
     return meta_ot(envinfo.mi_meta2_txnid, envinfo.mi_meta2_sign,
@@ -971,7 +971,7 @@ static __inline int meta_recent(const bool wanna_steady) {
                : 0;
 }
 
-static __inline int meta_tail(int head) {
+static int meta_tail(int head) {
   switch (head) {
   case 0:
     return meta_ot(envinfo.mi_meta1_txnid, envinfo.mi_meta1_sign,
@@ -1226,7 +1226,7 @@ int main(int argc, char *argv[]) {
   mdbx_setup_debug((verbose < MDBX_LOG_TRACE - 1)
                        ? (MDBX_log_level_t)(verbose + 1)
                        : MDBX_LOG_TRACE,
-                   MDBX_DBG_LEGACY_OVERLAP, logger);
+                   MDBX_DBG_LEGACY_OVERLAP | MDBX_DBG_DONT_UPGRADE, logger);
 
   rc = mdbx_env_create(&env);
   if (rc) {

src/options.h

@@ -361,17 +361,29 @@
 #endif /* MDBX_64BIT_CAS */
 
 #ifndef MDBX_UNALIGNED_OK
-#ifdef _MSC_VER
-#define MDBX_UNALIGNED_OK 1 /* avoid MSVC misoptimization */
+#if defined(__ALIGNED__) || defined(__SANITIZE_UNDEFINED__)
+#define MDBX_UNALIGNED_OK 0 /* no unaligned access allowed */
+#elif defined(__ARM_FEATURE_UNALIGNED)
+#define MDBX_UNALIGNED_OK 4 /* ok unaligned for 32-bit words */
 #elif __CLANG_PREREQ(5, 0) || __GNUC_PREREQ(5, 0)
-#define MDBX_UNALIGNED_OK 0 /* expecting optimization is well done */
-#elif (defined(__ia32__) || defined(__ARM_FEATURE_UNALIGNED)) &&               \
-    !defined(__ALIGNED__)
-#define MDBX_UNALIGNED_OK 1
-#else
+/* expecting an optimization will well done, also this
+ * hushes false-positives from UBSAN (undefined behaviour sanitizer) */
 #define MDBX_UNALIGNED_OK 0
+#elif defined(__e2k__) || defined(__elbrus__)
+#if __iset__ > 4
+#define MDBX_UNALIGNED_OK 8 /* ok unaligned for 64-bit words */
+#else
+#define MDBX_UNALIGNED_OK 4 /* ok unaligned for 32-bit words */
 #endif
-#endif /* MDBX_UNALIGNED_OK */
+#elif defined(__ia32__)
+#define MDBX_UNALIGNED_OK 8 /* ok unaligned for 64-bit words */
+#else
+#define MDBX_UNALIGNED_OK 0 /* no unaligned access allowed */
+#endif
+#elif MDBX_UNALIGNED_OK == 1
+#undef MDBX_UNALIGNED_OK
+#define MDBX_UNALIGNED_OK 32 /* any unaligned access allowed */
+#endif                       /* MDBX_UNALIGNED_OK */
 
 #ifndef MDBX_CACHELINE_SIZE
 #if defined(SYSTEM_CACHE_ALIGNMENT_SIZE)

test/long_stochastic.sh

@@ -144,9 +144,9 @@ case ${UNAME} in
     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))
+      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))
+      ram_avail_mb=$(($(LC_ALL=C free | grep -i Mem: | tr -s '[:blank:]' ' ' | cut -d ' ' -f 4) / 1024))
     fi
   ;;
 

test/utils.h

@@ -148,35 +148,31 @@ static __inline uint16_t bswap16(uint16_t v) { return v << 8 | v >> 8; }
 namespace unaligned {
 
 template <typename T> static __inline T load(const void *ptr) {
-#if defined(_MSC_VER) &&                                                       \
-    (defined(_M_ARM64) || defined(_M_X64) || defined(_M_IA64))
-  return *(const T __unaligned *)ptr;
-#elif MDBX_UNALIGNED_OK
-  return *(const T *)ptr;
+  if (MDBX_UNALIGNED_OK >= sizeof(T))
+    return *(const T *)ptr;
+  else {
+#if defined(__unaligned) || defined(_M_ARM) || defined(_M_ARM64) ||            \
+    defined(_M_X64) || defined(_M_IA64)
+    return *(const T __unaligned *)ptr;
 #else
-  T local;
-#if defined(__GNUC__) || defined(__clang__)
-  __builtin_memcpy(&local, (const T *)ptr, sizeof(T));
-#else
-  memcpy(&local, (const T *)ptr, sizeof(T));
-#endif /* __GNUC__ || __clang__ */
-  return local;
-#endif /* MDBX_UNALIGNED_OK */
+    T local;
+    memcpy(&local, (const T *)ptr, sizeof(T));
+    return local;
+#endif /* _MSC_VER || __unaligned */
+  }
 }
 
 template <typename T> static __inline void store(void *ptr, const T &value) {
-#if defined(_MSC_VER) &&                                                       \
-    (defined(_M_ARM64) || defined(_M_X64) || defined(_M_IA64))
-  *((T __unaligned *)ptr) = value;
-#elif MDBX_UNALIGNED_OK
-  *(volatile T *)ptr = value;
+  if (MDBX_UNALIGNED_OK >= sizeof(T))
+    *(T *)ptr = value;
+  else {
+#if defined(__unaligned) || defined(_M_ARM) || defined(_M_ARM64) ||            \
+    defined(_M_X64) || defined(_M_IA64)
+    *((T __unaligned *)ptr) = value;
 #else
-#if defined(__GNUC__) || defined(__clang__)
-  __builtin_memcpy(ptr, &value, sizeof(T));
-#else
-  memcpy(ptr, &value, sizeof(T));
-#endif /* __GNUC__ || __clang__ */
-#endif /* MDBX_UNALIGNED_OK */
+    memcpy(ptr, &value, sizeof(T));
+#endif /* _MSC_VER || __unaligned */
+  }
 }
 
 } /* namespace unaligned */

test/valgrind_suppress.txt

@@ -31,6 +31,20 @@
    fun:mdbx_wipe_steady
 }
 
+# memcmp() inside mdbx_iov_write() as workaround for https://github.com/erthink/libmdbx/issues/269
+{
+   write-page-check-bcmp
+   Memcheck:Cond
+   fun:bcmp
+   fun:mdbx_iov_write
+}
+{
+   write-page-check-memcmp
+   Memcheck:Cond
+   fun:memcmp*
+   fun:mdbx_iov_write
+}
+
 # single-page flush by pwrite()
 {
    pwrite-page-flush