mdbx: release v0.11.10

The stable bugfix release.
It is planned that this will be the last release of the v0.11 branch.

New:
----

 - The C++ API has been refined to simplify support for `wchar_t` in path names.
 - Added explicit error message for Buildroot's Microblaze toolchain maintainers.

Fixes:
------

 - Never use modern `__cxa_thread_atexit()` on Apple's OSes.
 - Use `MultiByteToWideChar(CP_THREAD_ACP)` instead of `mbstowcs()`.
 - Don't check owner for finished transactions.
 - Fixed typo in `MDBX_EINVAL` which breaks MingGW builds with CLANG.

Minors:
-------

 - Fixed variable name typo.
 - Using `ldd` to check used dso.
 - Added `MDBX_WEAK_IMPORT_ATTRIBUTE` macro.
 - Use current transaction geometry for untouched parameters when `env_set_geometry()` called within a write transaction.
 - Minor clarified `iov_page()` failure case.

14 files changed, 263 insertions(+), 252 deletions(-)
Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>

ChangeLog.md

@@ -1,10 +1,38 @@
 ChangeLog
 ---------
 
+## v0.11.10 (the TriColor) at 2022-08-22
+
+The stable bugfix release.
+It is planned that this will be the last release of the v0.11 branch.
+
+New:
+
+ - The C++ API has been refined to simplify support for `wchar_t` in path names.
+ - Added explicit error message for Buildroot's Microblaze toolchain maintainers.
+
+Fixes:
+
+ - Never use modern `__cxa_thread_atexit()` on Apple's OSes.
+ - Use `MultiByteToWideChar(CP_THREAD_ACP)` instead of `mbstowcs()`.
+ - Don't check owner for finished transactions.
+ - Fixed typo in `MDBX_EINVAL` which breaks MingGW builds with CLANG.
+
+Minors:
+
+ - Fixed variable name typo.
+ - Using `ldd` to check used dso.
+ - Added `MDBX_WEAK_IMPORT_ATTRIBUTE` macro.
+ - Use current transaction geometry for untouched parameters when `env_set_geometry()` called within a write transaction.
+ - Minor clarified `iov_page()` failure case.
+
+
+-------------------------------------------------------------------------------
+
+
 ## v0.11.9 (Чирчик-1992) at 2022-08-02
 
 The stable bugfix release.
-It is planned that this will be the last release of the v0.11 branch.
 
 ```
 18 files changed, 318 insertions(+), 178 deletions(-)

GNUmakefile

@@ -808,13 +808,13 @@ else
 define bench-rule
 bench-$(1)_$(2).txt: $(3) $(IOARENA) $(lastword $(MAKEFILE_LIST))
 	@echo '  RUNNING ioarena for $1/$2...'
-	$(QUIET)LD_LIBRARY_PATH="./:$$$${LD_LIBRARY_PATH}" \
+	$(QUIET)(export LD_LIBRARY_PATH="./:$$$${LD_LIBRARY_PATH}"; \
+		ldd $(IOARENA) && \
 		$(IOARENA) -D $(1) -B crud -m $(BENCH_CRUD_MODE) -n $(2) \
-		| tee $$@ | grep throughput && \
-	LD_LIBRARY_PATH="./:$$$${LD_LIBRARY_PATH}" \
-		$(IOARENA) -D $(1) -B get,iterate -m $(BENCH_CRUD_MODE) -r 4 -n $(2) \
-		| tee -a $$@ | grep throughput \
-	|| mv -f $$@ $$@.error
+			| tee $$@ | grep throughput && \
+		$(IOARENA) -D $(1) -B iterate,get,iterate,get,iterate -m $(BENCH_CRUD_MODE) -r 4 -n $(2) \
+			| tee -a $$@ | grep throughput \
+	) || mv -f $$@ $$@.error
 
 endef
 

src/base.h

@@ -157,12 +157,12 @@
 #define nullptr NULL
 #endif
 
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(_DARWIN_C_SOURCE)
 #include <AvailabilityMacros.h>
+#include <TargetConditionals.h>
 #ifndef MAC_OS_X_VERSION_MIN_REQUIRED
 #define MAC_OS_X_VERSION_MIN_REQUIRED 1070 /* Mac OS X 10.7, 2011 */
 #endif
-#include <TargetConditionals.h>
 #endif /* Apple OSX & iOS */
 
 #if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||     \
@@ -611,6 +611,19 @@ __extern_C key_t ftok(const char *, int);
 #endif
 #endif /* __anonymous_struct_extension__ */
 
+#ifndef MDBX_WEAK_IMPORT_ATTRIBUTE
+#ifdef WEAK_IMPORT_ATTRIBUTE
+#define MDBX_WEAK_IMPORT_ATTRIBUTE WEAK_IMPORT_ATTRIBUTE
+#elif __has_attribute(__weak__) && __has_attribute(__weak_import__)
+#define MDBX_WEAK_IMPORT_ATTRIBUTE __attribute__((__weak__, __weak_import__))
+#elif __has_attribute(__weak__) ||                                             \
+    (defined(__GNUC__) && __GNUC__ >= 4 && defined(__ELF__))
+#define MDBX_WEAK_IMPORT_ATTRIBUTE __attribute__((__weak__))
+#else
+#define MDBX_WEAK_IMPORT_ATTRIBUTE
+#endif
+#endif /* MDBX_WEAK_IMPORT_ATTRIBUTE */
+
 /*----------------------------------------------------------------------------*/
 
 #if defined(MDBX_USE_VALGRIND)

src/core.c

@@ -1269,55 +1269,50 @@ rthc_compare_and_clean(const void *rthc, const uint64_t signature) {
 
 static __inline int rthc_atexit(void (*dtor)(void *), void *obj,
                                 void *dso_symbol) {
-  int rc = MDBX_ENOSYS;
+#ifndef MDBX_HAVE_CXA_THREAD_ATEXIT_IMPL
+#if defined(LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL) ||                           \
+    defined(HAVE___CXA_THREAD_ATEXIT_IMPL) || __GLIBC_PREREQ(2, 18) ||         \
+    defined(ANDROID)
+#define MDBX_HAVE_CXA_THREAD_ATEXIT_IMPL 1
+#else
+#define MDBX_HAVE_CXA_THREAD_ATEXIT_IMPL 0
+#endif
+#endif /* MDBX_HAVE_CXA_THREAD_ATEXIT_IMPL */
 
-#if defined(__APPLE__) || defined(_DARWIN_C_SOURCE)
-#if !defined(MAC_OS_X_VERSION_MIN_REQUIRED) || !defined(MAC_OS_X_VERSION_10_7)
-#error                                                                         \
-    "The <AvailabilityMacros.h> should be included and MAC_OS_X_VERSION_MIN_REQUIRED must be defined"
-#elif MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_7
+#ifndef MDBX_HAVE_CXA_THREAD_ATEXIT
+#if defined(LIBCXXABI_HAS_CXA_THREAD_ATEXIT) ||                                \
+    defined(HAVE___CXA_THREAD_ATEXIT)
+#define MDBX_HAVE_CXA_THREAD_ATEXIT 1
+#elif !MDBX_HAVE_CXA_THREAD_ATEXIT_IMPL &&                                     \
+    (defined(__linux__) || defined(__gnu_linux__))
+#define MDBX_HAVE_CXA_THREAD_ATEXIT 1
+#else
+#define MDBX_HAVE_CXA_THREAD_ATEXIT 0
+#endif
+#endif /* MDBX_HAVE_CXA_THREAD_ATEXIT */
+
+  int rc = MDBX_ENOSYS;
+#if MDBX_HAVE_CXA_THREAD_ATEXIT_IMPL && !MDBX_HAVE_CXA_THREAD_ATEXIT
+#define __cxa_thread_atexit __cxa_thread_atexit_impl
+#endif
+#if MDBX_HAVE_CXA_THREAD_ATEXIT || defined(__cxa_thread_atexit)
+  extern int __cxa_thread_atexit(void (*dtor)(void *), void *obj,
+                                 void *dso_symbol) MDBX_WEAK_IMPORT_ATTRIBUTE;
+  if (&__cxa_thread_atexit)
+    rc = __cxa_thread_atexit(dtor, obj, dso_symbol);
+#elif defined(__APPLE__) || defined(_DARWIN_C_SOURCE)
   extern void _tlv_atexit(void (*termfunc)(void *objAddr), void *objAddr)
-      __attribute__((__weak__, __weak_import__));
-  if (rc && &_tlv_atexit) {
+      MDBX_WEAK_IMPORT_ATTRIBUTE;
+  if (&_tlv_atexit) {
     (void)dso_symbol;
     _tlv_atexit(dtor, obj);
     rc = 0;
   }
-#elif !defined(MDBX_HAVE_CXA_THREAD_ATEXIT)
-#define MDBX_HAVE_CXA_THREAD_ATEXIT 1
-#endif /* MAC_OS_X_VERSION_MIN_REQUIRED */
-#endif /* Apple */
-
-#if defined(MDBX_HAVE_CXA_THREAD_ATEXIT) && MDBX_HAVE_CXA_THREAD_ATEXIT
-  extern int __cxa_thread_atexit(void (*dtor)(void *), void *obj,
-                                 void *dso_symbol)
-#ifdef WEAK_IMPORT_ATTRIBUTE
-      WEAK_IMPORT_ATTRIBUTE
-#elif defined(MAC_OS_X_VERSION_MIN_REQUIRED) &&                                \
-    MAC_OS_X_VERSION_MIN_REQUIRED >= 1020 &&                                   \
-    ((__has_attribute(__weak__) && __has_attribute(__weak_import__)) ||        \
-     (defined(__GNUC__) && __GNUC__ >= 4))
-      __attribute__((__weak__, __weak_import__))
-#elif (__has_attribute(__weak__) || (defined(__GNUC__) && __GNUC__ >= 4)) &&   \
-    !defined(MAC_OS_X_VERSION_MIN_REQUIRED)
-      __attribute__((__weak__))
-#endif
-      ;
-  if (rc && &__cxa_thread_atexit)
-    rc = __cxa_thread_atexit(dtor, obj, dso_symbol);
-#elif __GLIBC_PREREQ(2, 18) || defined(ANDROID) || defined(__linux__) ||       \
-    defined(__gnu_linux__)
-  extern int __cxa_thread_atexit_impl(void (*dtor)(void *), void *obj,
-                                      void *dso_symbol)
-      __attribute__((__weak__));
-  if (rc && &__cxa_thread_atexit_impl)
-    rc = __cxa_thread_atexit_impl(dtor, obj, dso_symbol);
 #else
   (void)dtor;
   (void)obj;
   (void)dso_symbol;
 #endif
-
   return rc;
 }
 
@@ -5616,8 +5611,11 @@ static int mdbx_txn_spill(MDBX_txn *const txn, MDBX_cursor *const m0,
     txn->tw.dirtyroom += spilled;
     mdbx_tassert(txn, mdbx_dirtylist_check(txn));
 
-    if (ctx.iov_items)
+    if (ctx.iov_items) {
+      /* iov_page() frees dirty-pages and reset iov_items in case of failure. */
+      mdbx_tassert(txn, rc == MDBX_SUCCESS);
       rc = mdbx_iov_write(txn, &ctx);
+    }
 
     if (unlikely(rc != MDBX_SUCCESS))
       goto bailout;
@@ -8152,13 +8150,19 @@ static __always_inline int check_txn(const MDBX_txn *txn, int bad_bits) {
   if (unlikely(txn->mt_flags & bad_bits))
     return MDBX_BAD_TXN;
 
+  mdbx_tassert(txn, (txn->mt_flags & MDBX_NOTLS) ==
+                        ((txn->mt_flags & MDBX_TXN_RDONLY)
+                             ? txn->mt_env->me_flags & MDBX_NOTLS
+                             : 0));
 #if MDBX_TXN_CHECKOWNER
-  if ((txn->mt_flags & MDBX_NOTLS) == 0 &&
-      unlikely(txn->mt_owner != mdbx_thread_self()))
+  STATIC_ASSERT(MDBX_NOTLS > MDBX_TXN_FINISHED + MDBX_TXN_RDONLY);
+  if (unlikely(txn->mt_owner != mdbx_thread_self()) &&
+      (txn->mt_flags & (MDBX_NOTLS | MDBX_TXN_FINISHED | MDBX_TXN_RDONLY)) <
+          (MDBX_TXN_FINISHED | MDBX_TXN_RDONLY))
     return txn->mt_owner ? MDBX_THREAD_MISMATCH : MDBX_BAD_TXN;
 #endif /* MDBX_TXN_CHECKOWNER */
 
-  if (unlikely(!txn->mt_env->me_map))
+  if (bad_bits && unlikely(!txn->mt_env->me_map))
     return MDBX_EPERM;
 
   return MDBX_SUCCESS;
@@ -8959,6 +8963,9 @@ int mdbx_txn_abort(MDBX_txn *txn) {
     return mdbx_txn_end(txn, MDBX_END_ABORT | MDBX_END_UPDATE | MDBX_END_SLOT |
                                  MDBX_END_FREE);
 
+  if (unlikely(txn->mt_flags & MDBX_TXN_FINISHED))
+    return MDBX_BAD_TXN;
+
   if (txn->mt_child)
     mdbx_txn_abort(txn->mt_child);
 
@@ -9975,8 +9982,11 @@ static int mdbx_txn_write(MDBX_txn *txn, struct mdbx_iov_ctx *ctx) {
       break;
   }
 
-  if (ctx->iov_items)
+  if (ctx->iov_items) {
+    /* iov_page() frees dirty-pages and reset iov_items in case of failure. */
+    mdbx_tassert(txn, rc == MDBX_SUCCESS);
     rc = mdbx_iov_write(txn, ctx);
+  }
 
   while (r <= dl->length)
     dl->items[++w] = dl->items[r++];
@@ -11672,38 +11682,40 @@ mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower, intptr_t size_now,
     if (unlikely(env->me_flags & MDBX_RDONLY))
       return MDBX_EACCESS;
 
-    if (!inside_txn) {
+    const MDBX_geo *geo = nullptr;
+    if (inside_txn)
+      geo = &env->me_txn->mt_geo;
+    else {
       int err = mdbx_txn_lock(env, false);
       if (unlikely(err != MDBX_SUCCESS))
         return err;
       need_unlock = true;
-    }
-    const MDBX_meta *head = constmeta_prefer_last(env);
-    if (!inside_txn) {
+
+      const MDBX_meta *head = constmeta_prefer_last(env);
+      geo = &head->mm_geo;
       env->me_txn0->mt_txnid = constmeta_txnid(env, head);
       mdbx_find_oldest(env->me_txn0);
     }
 
-    /* get untouched params from DB */
+    /* get untouched params from current write-txn or DB */
     if (pagesize <= 0 || pagesize >= INT_MAX)
       pagesize = env->me_psize;
     if (size_lower < 0)
-      size_lower = pgno2bytes(env, head->mm_geo.lower);
+      size_lower = pgno2bytes(env, geo->lower);
     if (size_now < 0)
-      size_now = pgno2bytes(env, head->mm_geo.now);
+      size_now = pgno2bytes(env, geo->now);
     if (size_upper < 0)
-      size_upper = pgno2bytes(env, head->mm_geo.upper);
+      size_upper = pgno2bytes(env, geo->upper);
     if (growth_step < 0)
-      growth_step = pgno2bytes(env, pv2pages(head->mm_geo.grow_pv));
+      growth_step = pgno2bytes(env, pv2pages(geo->grow_pv));
     if (shrink_threshold < 0)
-      shrink_threshold = pgno2bytes(env, pv2pages(head->mm_geo.shrink_pv));
+      shrink_threshold = pgno2bytes(env, pv2pages(geo->shrink_pv));
 
     if (pagesize != (intptr_t)env->me_psize) {
       rc = MDBX_EINVAL;
       goto bailout;
     }
-    const size_t usedbytes =
-        pgno2bytes(env, mdbx_find_largest(env, head->mm_geo.next));
+    const size_t usedbytes = pgno2bytes(env, mdbx_find_largest(env, geo->next));
     if ((size_t)size_upper < usedbytes) {
       rc = MDBX_MAP_FULL;
       goto bailout;
@@ -12439,7 +12451,7 @@ __cold static int mdbx_setup_dxb(MDBX_env *env, const int lck_rc,
       } else {
         const txnid_t txnid = constmeta_txnid(env, head);
         const txnid_t next_txnid = safe64_txnid_next(txnid);
-        if (unlikely(txnid > MAX_TXNID)) {
+        if (unlikely(next_txnid > MAX_TXNID)) {
           mdbx_error("txnid overflow, raise %d", MDBX_TXN_FULL);
           return MDBX_TXN_FULL;
         }
@@ -12972,12 +12984,8 @@ __cold static int mdbx_handle_env_pathname(MDBX_handle_env_pathname *ctx,
     return MDBX_EINVAL;
 
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
+  const wchar_t *pathnameW = nullptr;
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
 
   const DWORD dwAttrib = GetFileAttributesW(pathnameW);
   if (dwAttrib == INVALID_FILE_ATTRIBUTES) {
@@ -15251,7 +15259,7 @@ int mdbx_cursor_get_batch(MDBX_cursor *mc, size_t *count, MDBX_val *pairs,
     break;
   default:
     mdbx_debug("unhandled/unimplemented cursor operation %u", op);
-    rc = EINVAL;
+    rc = MDBX_EINVAL;
     break;
   }
 

src/lck-posix.c

@@ -201,9 +201,12 @@ static int lck_op(const mdbx_filehandle_t fd, int cmd, const int lck,
          ((uint64_t)offset + (uint64_t)len));
   for (;;) {
     struct flock lock_op;
-    STATIC_ASSERT(sizeof(off_t) <= sizeof(lock_op.l_start) &&
-                  sizeof(off_t) <= sizeof(lock_op.l_len) &&
-                  OFF_T_MAX == (off_t)OFF_T_MAX);
+    STATIC_ASSERT_MSG(sizeof(off_t) <= sizeof(lock_op.l_start) &&
+                          sizeof(off_t) <= sizeof(lock_op.l_len) &&
+                          OFF_T_MAX == (off_t)OFF_T_MAX,
+                      "Support for large/64-bit-sized files is misconfigured "
+                      "for the target system and/or toolchain. "
+                      "Please fix it or at least disable it completely.");
     memset(&lock_op, 0, sizeof(lock_op));
     lock_op.l_type = lck;
     lock_op.l_whence = SEEK_SET;

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 "2022-08-02" "MDBX 0.11.9"
+.TH MDBX_CHK 1 "2022-08-22" "MDBX 0.11.10"
 .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 "2022-08-02" "MDBX 0.11.9"
+.TH MDBX_COPY 1 "2022-08-22" "MDBX 0.11.10"
 .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 "2022-08-02" "MDBX 0.11.9"
+.TH MDBX_DROP 1 "2022-08-22" "MDBX 0.11.10"
 .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 "2022-08-02" "MDBX 0.11.9"
+.TH MDBX_DUMP 1 "2022-08-22" "MDBX 0.11.10"
 .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 "2022-08-02" "MDBX 0.11.9"
+.TH MDBX_LOAD 1 "2022-08-22" "MDBX 0.11.10"
 .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 "2022-08-02" "MDBX 0.11.9"
+.TH MDBX_STAT 1 "2022-08-22" "MDBX 0.11.10"
 .SH NAME
 mdbx_stat \- MDBX environment status tool
 .SH SYNOPSIS

src/mdbx.c++

@@ -203,58 +203,35 @@ __cold  bug::~bug() noexcept {}
 
 //------------------------------------------------------------------------------
 
-template <typename PATH> struct path_to_pchar {
-  const std::string str;
-  path_to_pchar(const PATH &path) : str(path.generic_string()) {}
-  operator const char *() const { return str.c_str(); }
-};
-
-template <typename PATH>
-MDBX_MAYBE_UNUSED PATH pchar_to_path(const char *c_str) {
-  return PATH(c_str);
-}
-
 #if defined(_WIN32) || defined(_WIN64)
 
-#ifndef WC_ERR_INVALID_CHARS
-static const DWORD WC_ERR_INVALID_CHARS =
-    (6 /* Windows Vista */ <= /* MajorVersion */ LOBYTE(LOWORD(GetVersion())))
-        ? 0x00000080
-        : 0;
-#endif /* WC_ERR_INVALID_CHARS */
-
-template <> struct path_to_pchar<std::wstring> {
-  std::string str;
-  path_to_pchar(const std::wstring &path) {
-    if (!path.empty()) {
-      const int chars =
-          WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, path.data(),
-                              int(path.size()), nullptr, 0, nullptr, nullptr);
-      if (chars == 0)
-        mdbx::error::throw_exception(GetLastError());
-      str.append(chars, '\0');
-      WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, path.data(),
-                          int(path.size()), const_cast<char *>(str.data()),
-                          chars, nullptr, nullptr);
-    }
-  }
-  operator const char *() const { return str.c_str(); }
-};
-
-template <>
-MDBX_MAYBE_UNUSED std::wstring pchar_to_path<std::wstring>(const char *c_str) {
-  std::wstring wstr;
-  if (c_str && *c_str) {
-    const int chars = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, c_str,
-                                          int(strlen(c_str)), nullptr, 0);
-    if (chars == 0)
+std::string w2mb(const std::wstring &in) {
+  std::string out;
+  if (!in.empty()) {
+    const auto out_len = mdbx_w2mb(nullptr, 0, in.data(), in.size());
+    if (out_len < 1)
+      mdbx::error::throw_exception(GetLastError());
+    out.append(out_len, '\0');
+    if (out_len != mdbx_w2mb(const_cast<char *>(out.data()), out_len, in.data(),
+                             in.size()))
       mdbx::error::throw_exception(GetLastError());
-    wstr.append(chars, '\0');
-    MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, c_str,
-                        int(strlen(c_str)), const_cast<wchar_t *>(wstr.data()),
-                        chars);
   }
-  return wstr;
+  return out;
+}
+
+std::wstring mb2w(const char *in) {
+  std::wstring out;
+  if (in && *in) {
+    const auto in_len = strlen(in);
+    const auto out_len = mdbx_mb2w(nullptr, 0, in, in_len);
+    if (out_len < 1)
+      mdbx::error::throw_exception(GetLastError());
+    out.append(out_len, '\0');
+    if (out_len !=
+        mdbx_mb2w(const_cast<wchar_t *>(out.data()), out_len, in, in_len))
+      mdbx::error::throw_exception(GetLastError());
+  }
+  return out;
 }
 
 #endif /* Windows */
@@ -1239,31 +1216,14 @@ bool env::is_pristine() const {
 
 bool env::is_empty() const { return get_stat().ms_leaf_pages == 0; }
 
-#ifdef MDBX_STD_FILESYSTEM_PATH
-env &env::copy(const MDBX_STD_FILESYSTEM_PATH &destination, bool compactify,
-               bool force_dynamic_size) {
-  const path_to_pchar<MDBX_STD_FILESYSTEM_PATH> utf8(destination);
+env &env::copy(filehandle fd, bool compactify, bool force_dynamic_size) {
   error::success_or_throw(
-      ::mdbx_env_copy(handle_, utf8,
-                      (compactify ? MDBX_CP_COMPACT : MDBX_CP_DEFAULTS) |
-                          (force_dynamic_size ? MDBX_CP_FORCE_DYNAMIC_SIZE
-                                              : MDBX_CP_DEFAULTS)));
+      ::mdbx_env_copy2fd(handle_, fd,
+                         (compactify ? MDBX_CP_COMPACT : MDBX_CP_DEFAULTS) |
+                             (force_dynamic_size ? MDBX_CP_FORCE_DYNAMIC_SIZE
+                                                 : MDBX_CP_DEFAULTS)));
   return *this;
 }
-#endif /* MDBX_STD_FILESYSTEM_PATH */
-
-#if defined(_WIN32) || defined(_WIN64)
-env &env::copy(const ::std::wstring &destination, bool compactify,
-               bool force_dynamic_size) {
-  const path_to_pchar<::std::wstring> utf8(destination);
-  error::success_or_throw(
-      ::mdbx_env_copy(handle_, utf8,
-                      (compactify ? MDBX_CP_COMPACT : MDBX_CP_DEFAULTS) |
-                          (force_dynamic_size ? MDBX_CP_FORCE_DYNAMIC_SIZE
-                                              : MDBX_CP_DEFAULTS)));
-  return *this;
-}
-#endif /* Windows */
 
 env &env::copy(const char *destination, bool compactify,
                bool force_dynamic_size) {
@@ -1280,38 +1240,32 @@ env &env::copy(const ::std::string &destination, bool compactify,
   return copy(destination.c_str(), compactify, force_dynamic_size);
 }
 
-env &env::copy(filehandle fd, bool compactify, bool force_dynamic_size) {
-  error::success_or_throw(
-      ::mdbx_env_copy2fd(handle_, fd,
-                         (compactify ? MDBX_CP_COMPACT : MDBX_CP_DEFAULTS) |
-                             (force_dynamic_size ? MDBX_CP_FORCE_DYNAMIC_SIZE
-                                                 : MDBX_CP_DEFAULTS)));
-  return *this;
-}
-
-path env::get_path() const {
-  const char *c_str;
-  error::success_or_throw(::mdbx_env_get_path(handle_, &c_str));
-  return pchar_to_path<path>(c_str);
-}
-
 #ifdef MDBX_STD_FILESYSTEM_PATH
-bool env::remove(const MDBX_STD_FILESYSTEM_PATH &pathname,
-                 const remove_mode mode) {
-  const path_to_pchar<MDBX_STD_FILESYSTEM_PATH> utf8(pathname);
-  return error::boolean_or_throw(
-      ::mdbx_env_delete(utf8, MDBX_env_delete_mode_t(mode)));
+env &env::copy(const MDBX_STD_FILESYSTEM_PATH &destination, bool compactify,
+               bool force_dynamic_size) {
+  return copy(destination.native(), compactify, force_dynamic_size);
 }
 #endif /* MDBX_STD_FILESYSTEM_PATH */
 
 #if defined(_WIN32) || defined(_WIN64)
-bool env::remove(const ::std::wstring &pathname, const remove_mode mode) {
-  const path_to_pchar<::std::wstring> utf8(pathname);
-  return error::boolean_or_throw(
-      ::mdbx_env_delete(utf8, MDBX_env_delete_mode_t(mode)));
+env &env::copy(const ::std::wstring &destination, bool compactify,
+               bool force_dynamic_size) {
+  return copy(w2mb(destination), compactify, force_dynamic_size);
 }
 #endif /* Windows */
 
+path env::get_path() const {
+  const char *c_str;
+  error::success_or_throw(::mdbx_env_get_path(handle_, &c_str));
+#if defined(_WIN32) || defined(_WIN64)
+  static_assert(sizeof(path::value_type) == sizeof(wchar_t), "Oops");
+  return path(mb2w(c_str));
+#else
+  static_assert(sizeof(path::value_type) == sizeof(char), "Oops");
+  return path(c_str);
+#endif
+}
+
 bool env::remove(const char *pathname, const remove_mode mode) {
   return error::boolean_or_throw(
       ::mdbx_env_delete(pathname, MDBX_env_delete_mode_t(mode)));
@@ -1321,6 +1275,19 @@ bool env::remove(const ::std::string &pathname, const remove_mode mode) {
   return remove(pathname.c_str(), mode);
 }
 
+#ifdef MDBX_STD_FILESYSTEM_PATH
+bool env::remove(const MDBX_STD_FILESYSTEM_PATH &pathname,
+                 const remove_mode mode) {
+  return remove(pathname.native(), mode);
+}
+#endif /* MDBX_STD_FILESYSTEM_PATH */
+
+#if defined(_WIN32) || defined(_WIN64)
+bool env::remove(const ::std::wstring &pathname, const remove_mode mode) {
+  return remove(w2mb(pathname), mode);
+}
+#endif /* Windows */
+
 //------------------------------------------------------------------------------
 
 static inline MDBX_env *create_env() {
@@ -1357,68 +1324,6 @@ __cold void env_managed::setup(unsigned max_maps, unsigned max_readers) {
     error::success_or_throw(::mdbx_env_set_maxdbs(handle_, max_maps));
 }
 
-#ifdef MDBX_STD_FILESYSTEM_PATH
-__cold env_managed::env_managed(const MDBX_STD_FILESYSTEM_PATH &pathname,
-                                const operate_parameters &op, bool accede)
-    : env_managed(create_env()) {
-  setup(op.max_maps, op.max_readers);
-  const path_to_pchar<MDBX_STD_FILESYSTEM_PATH> utf8(pathname);
-  error::success_or_throw(
-      ::mdbx_env_open(handle_, utf8, op.make_flags(accede), 0));
-
-  if (op.options.nested_write_transactions &&
-      !get_options().nested_write_transactions)
-    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
-}
-
-__cold env_managed::env_managed(const MDBX_STD_FILESYSTEM_PATH &pathname,
-                                const env_managed::create_parameters &cp,
-                                const env::operate_parameters &op, bool accede)
-    : env_managed(create_env()) {
-  setup(op.max_maps, op.max_readers);
-  const path_to_pchar<MDBX_STD_FILESYSTEM_PATH> utf8(pathname);
-  set_geometry(cp.geometry);
-  error::success_or_throw(
-      ::mdbx_env_open(handle_, utf8, op.make_flags(accede, cp.use_subdirectory),
-                      cp.file_mode_bits));
-
-  if (op.options.nested_write_transactions &&
-      !get_options().nested_write_transactions)
-    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
-}
-#endif /* MDBX_STD_FILESYSTEM_PATH */
-
-#if defined(_WIN32) || defined(_WIN64)
-__cold env_managed::env_managed(const ::std::wstring &pathname,
-                                const operate_parameters &op, bool accede)
-    : env_managed(create_env()) {
-  setup(op.max_maps, op.max_readers);
-  const path_to_pchar<::std::wstring> utf8(pathname);
-  error::success_or_throw(
-      ::mdbx_env_open(handle_, utf8, op.make_flags(accede), 0));
-
-  if (op.options.nested_write_transactions &&
-      !get_options().nested_write_transactions)
-    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
-}
-
-__cold env_managed::env_managed(const ::std::wstring &pathname,
-                                const env_managed::create_parameters &cp,
-                                const env::operate_parameters &op, bool accede)
-    : env_managed(create_env()) {
-  setup(op.max_maps, op.max_readers);
-  const path_to_pchar<::std::wstring> utf8(pathname);
-  set_geometry(cp.geometry);
-  error::success_or_throw(
-      ::mdbx_env_open(handle_, utf8, op.make_flags(accede, cp.use_subdirectory),
-                      cp.file_mode_bits));
-
-  if (op.options.nested_write_transactions &&
-      !get_options().nested_write_transactions)
-    MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_INCOMPATIBLE);
-}
-#endif /* Windows */
-
 __cold env_managed::env_managed(const char *pathname,
                                 const operate_parameters &op, bool accede)
     : env_managed(create_env()) {
@@ -1455,6 +1360,28 @@ __cold env_managed::env_managed(const ::std::string &pathname,
                                 const env::operate_parameters &op, bool accede)
     : env_managed(pathname.c_str(), cp, op, accede) {}
 
+#ifdef MDBX_STD_FILESYSTEM_PATH
+__cold env_managed::env_managed(const MDBX_STD_FILESYSTEM_PATH &pathname,
+                                const operate_parameters &op, bool accede)
+    : env_managed(pathname.native(), op, accede) {}
+
+__cold env_managed::env_managed(const MDBX_STD_FILESYSTEM_PATH &pathname,
+                                const env_managed::create_parameters &cp,
+                                const env::operate_parameters &op, bool accede)
+    : env_managed(pathname.native(), cp, op, accede) {}
+#endif /* MDBX_STD_FILESYSTEM_PATH */
+
+#if defined(_WIN32) || defined(_WIN64)
+__cold env_managed::env_managed(const ::std::wstring &pathname,
+                                const operate_parameters &op, bool accede)
+    : env_managed(w2mb(pathname), op, accede) {}
+
+__cold env_managed::env_managed(const ::std::wstring &pathname,
+                                const env_managed::create_parameters &cp,
+                                const env::operate_parameters &op, bool accede)
+    : env_managed(w2mb(pathname), cp, op, accede) {}
+#endif /* Windows */
+
 //------------------------------------------------------------------------------
 
 txn_managed txn::start_nested() {

src/osal.c

@@ -518,14 +518,35 @@ MDBX_INTERNAL_FUNC int mdbx_fastmutex_release(mdbx_fastmutex_t *fastmutex) {
 
 /*----------------------------------------------------------------------------*/
 
+#if defined(_WIN32) || defined(_WIN64)
+
+#ifndef WC_ERR_INVALID_CHARS
+static const DWORD WC_ERR_INVALID_CHARS =
+    (6 /* Windows Vista */ <= /* MajorVersion */ LOBYTE(LOWORD(GetVersion())))
+        ? 0x00000080
+        : 0;
+#endif /* WC_ERR_INVALID_CHARS */
+
+MDBX_INTERNAL_FUNC size_t mdbx_mb2w(wchar_t *dst, size_t dst_n, const char *src,
+                                    size_t src_n) {
+  return MultiByteToWideChar(CP_THREAD_ACP, MB_ERR_INVALID_CHARS, src,
+                             (int)src_n, dst, (int)dst_n);
+}
+
+MDBX_INTERNAL_FUNC size_t mdbx_w2mb(char *dst, size_t dst_n, const wchar_t *src,
+                                    size_t src_n) {
+  return WideCharToMultiByte(CP_THREAD_ACP, WC_ERR_INVALID_CHARS, src,
+                             (int)src_n, dst, (int)dst_n, nullptr, nullptr);
+}
+
+#endif /* Windows */
+
+/*----------------------------------------------------------------------------*/
+
 MDBX_INTERNAL_FUNC int mdbx_removefile(const char *pathname) {
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
+  const wchar_t *pathnameW = nullptr;
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
   return DeleteFileW(pathnameW) ? MDBX_SUCCESS : (int)GetLastError();
 #else
   return unlink(pathname) ? errno : MDBX_SUCCESS;
@@ -538,12 +559,8 @@ static bool is_valid_fd(int fd) { return !(isatty(fd) < 0 && errno == EBADF); }
 
 MDBX_INTERNAL_FUNC int mdbx_removedirectory(const char *pathname) {
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
+  const wchar_t *pathnameW = nullptr;
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
   return RemoveDirectoryW(pathnameW) ? MDBX_SUCCESS : (int)GetLastError();
 #else
   return rmdir(pathname) ? errno : MDBX_SUCCESS;
@@ -557,12 +574,8 @@ MDBX_INTERNAL_FUNC int mdbx_openfile(const enum mdbx_openfile_purpose purpose,
   *fd = INVALID_HANDLE_VALUE;
 
 #if defined(_WIN32) || defined(_WIN64)
-  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);
-  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)
-    return ERROR_INVALID_NAME;
-  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));
-  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))
-    return ERROR_INVALID_NAME;
+  const wchar_t *pathnameW = nullptr;
+  MUSTDIE_MB2WIDE(pathname, pathnameW);
 
   DWORD CreationDisposition = unix_mode_bits ? OPEN_ALWAYS : OPEN_EXISTING;
   DWORD FlagsAndAttributes =

src/osal.h

@@ -180,6 +180,11 @@ static inline void mdbx_free(void *ptr) { HeapFree(GetProcessHeap(), 0, ptr); }
 #define vsnprintf _vsnprintf /* ntdll */
 #endif
 
+MDBX_INTERNAL_FUNC size_t mdbx_mb2w(wchar_t *dst, size_t dst_n, const char *src,
+                                    size_t src_n);
+MDBX_INTERNAL_FUNC size_t mdbx_w2mb(char *dst, size_t dst_n, const wchar_t *src,
+                                    size_t src_n);
+
 #else /*----------------------------------------------------------------------*/
 
 typedef pthread_t mdbx_thread_t;
@@ -549,6 +554,20 @@ MDBX_INTERNAL_FUNC int mdbx_rpid_check(MDBX_env *env, uint32_t pid);
 
 #if defined(_WIN32) || defined(_WIN64)
 
+#define MUSTDIE_MB2WIDE(FROM, TO)                                              \
+  do {                                                                         \
+    const char *const from_tmp = (FROM);                                       \
+    const size_t from_mblen = strlen(from_tmp);                                \
+    const size_t to_wlen = mdbx_mb2w(nullptr, 0, from_tmp, from_mblen);        \
+    if (to_wlen < 1 || to_wlen > /* MAX_PATH */ INT16_MAX)                     \
+      return ERROR_INVALID_NAME;                                               \
+    wchar_t *const to_tmp = _alloca((to_wlen + 1) * sizeof(wchar_t));          \
+    if (to_wlen + 1 !=                                                         \
+        mdbx_mb2w(to_tmp, to_wlen + 1, from_tmp, from_mblen + 1))              \
+      return ERROR_INVALID_NAME;                                               \
+    (TO) = to_tmp;                                                             \
+  } while (0)
+
 typedef void(WINAPI *MDBX_srwlock_function)(MDBX_srwlock *);
 MDBX_INTERNAL_VAR MDBX_srwlock_function mdbx_srwlock_Init,
     mdbx_srwlock_AcquireShared, mdbx_srwlock_ReleaseShared,