mdbx: изменение лицензии и реструктуризация исходного кода.

src/windows-import.c

@@ -0,0 +1,158 @@
+/// \copyright SPDX-License-Identifier: Apache-2.0
+/// \author Леонид Юрьев aka Leonid Yuriev <leo@yuriev.ru> \date 2015-2024
+
+#if defined(_WIN32) || defined(_WIN64)
+
+#include "internals.h"
+
+//------------------------------------------------------------------------------
+// Stub for slim read-write lock
+// Portion Copyright (C) 1995-2002 Brad Wilson
+
+static void WINAPI stub_srwlock_Init(osal_srwlock_t *srwl) {
+  srwl->readerCount = srwl->writerCount = 0;
+}
+
+static void WINAPI stub_srwlock_AcquireShared(osal_srwlock_t *srwl) {
+  while (true) {
+    assert(srwl->writerCount >= 0 && srwl->readerCount >= 0);
+
+    //  If there's a writer already, spin without unnecessarily
+    //  interlocking the CPUs
+    if (srwl->writerCount != 0) {
+      SwitchToThread();
+      continue;
+    }
+
+    //  Add to the readers list
+    _InterlockedIncrement(&srwl->readerCount);
+
+    // Check for writers again (we may have been preempted). If
+    // there are no writers writing or waiting, then we're done.
+    if (srwl->writerCount == 0)
+      break;
+
+    // Remove from the readers list, spin, try again
+    _InterlockedDecrement(&srwl->readerCount);
+    SwitchToThread();
+  }
+}
+
+static void WINAPI stub_srwlock_ReleaseShared(osal_srwlock_t *srwl) {
+  assert(srwl->readerCount > 0);
+  _InterlockedDecrement(&srwl->readerCount);
+}
+
+static void WINAPI stub_srwlock_AcquireExclusive(osal_srwlock_t *srwl) {
+  while (true) {
+    assert(srwl->writerCount >= 0 && srwl->readerCount >= 0);
+
+    //  If there's a writer already, spin without unnecessarily
+    //  interlocking the CPUs
+    if (srwl->writerCount != 0) {
+      SwitchToThread();
+      continue;
+    }
+
+    // See if we can become the writer (expensive, because it inter-
+    // locks the CPUs, so writing should be an infrequent process)
+    if (_InterlockedExchange(&srwl->writerCount, 1) == 0)
+      break;
+  }
+
+  // Now we're the writer, but there may be outstanding readers.
+  // Spin until there aren't any more; new readers will wait now
+  // that we're the writer.
+  while (srwl->readerCount != 0) {
+    assert(srwl->writerCount >= 0 && srwl->readerCount >= 0);
+    SwitchToThread();
+  }
+}
+
+static void WINAPI stub_srwlock_ReleaseExclusive(osal_srwlock_t *srwl) {
+  assert(srwl->writerCount == 1 && srwl->readerCount >= 0);
+  srwl->writerCount = 0;
+}
+
+static uint64_t WINAPI stub_GetTickCount64(void) {
+  LARGE_INTEGER Counter, Frequency;
+  return (QueryPerformanceFrequency(&Frequency) &&
+          QueryPerformanceCounter(&Counter))
+             ? Counter.QuadPart * 1000ul / Frequency.QuadPart
+             : 0;
+}
+
+//------------------------------------------------------------------------------
+
+struct libmdbx_imports imports;
+
+#if __GNUC_PREREQ(8, 0)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-function-type"
+#endif /* GCC/MINGW */
+
+#define MDBX_IMPORT(HANDLE, ENTRY)                                             \
+  imports.ENTRY = (MDBX_##ENTRY)GetProcAddress(HANDLE, #ENTRY)
+
+void windows_import(void) {
+  const HINSTANCE hNtdll = GetModuleHandleA("ntdll.dll");
+  if (hNtdll) {
+    globals.running_under_Wine = !!GetProcAddress(hNtdll, "wine_get_version");
+    if (!globals.running_under_Wine) {
+      MDBX_IMPORT(hNtdll, NtFsControlFile);
+      MDBX_IMPORT(hNtdll, NtExtendSection);
+      ENSURE(nullptr, imports.NtExtendSection);
+    }
+  }
+
+  const HINSTANCE hKernel32dll = GetModuleHandleA("kernel32.dll");
+  if (hKernel32dll) {
+    MDBX_IMPORT(hKernel32dll, GetFileInformationByHandleEx);
+    MDBX_IMPORT(hKernel32dll, GetTickCount64);
+    if (!imports.GetTickCount64)
+      imports.GetTickCount64 = stub_GetTickCount64;
+    if (!globals.running_under_Wine) {
+      MDBX_IMPORT(hKernel32dll, SetFileInformationByHandle);
+      MDBX_IMPORT(hKernel32dll, GetVolumeInformationByHandleW);
+      MDBX_IMPORT(hKernel32dll, GetFinalPathNameByHandleW);
+      MDBX_IMPORT(hKernel32dll, PrefetchVirtualMemory);
+      MDBX_IMPORT(hKernel32dll, SetFileIoOverlappedRange);
+    }
+  }
+
+  const osal_srwlock_t_function srwlock_init =
+      (osal_srwlock_t_function)(hKernel32dll
+                                    ? GetProcAddress(hKernel32dll,
+                                                     "InitializeSRWLock")
+                                    : nullptr);
+  if (srwlock_init) {
+    imports.srwl_Init = srwlock_init;
+    imports.srwl_AcquireShared = (osal_srwlock_t_function)GetProcAddress(
+        hKernel32dll, "AcquireSRWLockShared");
+    imports.srwl_ReleaseShared = (osal_srwlock_t_function)GetProcAddress(
+        hKernel32dll, "ReleaseSRWLockShared");
+    imports.srwl_AcquireExclusive = (osal_srwlock_t_function)GetProcAddress(
+        hKernel32dll, "AcquireSRWLockExclusive");
+    imports.srwl_ReleaseExclusive = (osal_srwlock_t_function)GetProcAddress(
+        hKernel32dll, "ReleaseSRWLockExclusive");
+  } else {
+    imports.srwl_Init = stub_srwlock_Init;
+    imports.srwl_AcquireShared = stub_srwlock_AcquireShared;
+    imports.srwl_ReleaseShared = stub_srwlock_ReleaseShared;
+    imports.srwl_AcquireExclusive = stub_srwlock_AcquireExclusive;
+    imports.srwl_ReleaseExclusive = stub_srwlock_ReleaseExclusive;
+  }
+
+  const HINSTANCE hAdvapi32dll = GetModuleHandleA("advapi32.dll");
+  if (hAdvapi32dll) {
+    MDBX_IMPORT(hAdvapi32dll, RegGetValueA);
+  }
+}
+
+#undef MDBX_IMPORT
+
+#if __GNUC_PREREQ(8, 0)
+#pragma GCC diagnostic pop
+#endif /* GCC/MINGW */
+
+#endif /* Windows */