-/*
- * file-mmap-posix.c: File mmap internal calls
+/**
+ * \file
+ * MemoryMappedFile internal calls for Windows
*
- * Author:
- * Rodrigo Kumpera
+ * Copyright 2016 Microsoft
+ * Licensed under the MIT license. See LICENSE file in the project root for full license information.
+ */
+
+/*
+ * The code in this file has been inspired by the CoreFX MemoryMappedFile Windows implementation contained in the files
*
- * Copyright 2014 Xamarin Inc (http://www.xamarin.com)
+ * https://github.com/dotnet/corefx/blob/master/src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedFile.Windows.cs
+ * https://github.com/dotnet/corefx/blob/master/src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedView.Windows.cs
*/
#include <config.h>
-
-#ifdef HOST_WIN32
-
#include <glib.h>
-#include <string.h>
-#include <errno.h>
+#include <mono/utils/mono-compiler.h>
+#if G_HAVE_API_SUPPORT(HAVE_CLASSIC_WINAPI_SUPPORT) && defined(HOST_WIN32)
+#include <glib.h>
-#include <mono/metadata/object.h>
#include <mono/metadata/file-mmap.h>
-void *
-mono_mmap_open_file (MonoString *path, int mode, MonoString *mapName, gint64 *capacity, int access, int options, int *error)
+// These control the retry behaviour when lock violation errors occur during Flush:
+#define MAX_FLUSH_WAITS 15 // must be <=30
+#define MAX_FLUSH_RETIRES_PER_WAIT 20
+
+typedef struct {
+ void *address;
+ size_t length;
+} MmapInstance;
+
+enum {
+ BAD_CAPACITY_FOR_FILE_BACKED = 1,
+ CAPACITY_SMALLER_THAN_FILE_SIZE,
+ FILE_NOT_FOUND,
+ FILE_ALREADY_EXISTS,
+ PATH_TOO_LONG,
+ COULD_NOT_OPEN,
+ CAPACITY_MUST_BE_POSITIVE,
+ INVALID_FILE_MODE,
+ COULD_NOT_MAP_MEMORY,
+ ACCESS_DENIED,
+ CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE
+};
+
+enum {
+ FILE_MODE_CREATE_NEW = 1,
+ FILE_MODE_CREATE = 2,
+ FILE_MODE_OPEN = 3,
+ FILE_MODE_OPEN_OR_CREATE = 4,
+ FILE_MODE_TRUNCATE = 5,
+ FILE_MODE_APPEND = 6,
+};
+
+enum {
+ MMAP_FILE_ACCESS_READ_WRITE = 0,
+ MMAP_FILE_ACCESS_READ = 1,
+ MMAP_FILE_ACCESS_WRITE = 2,
+ MMAP_FILE_ACCESS_COPY_ON_WRITE = 3,
+ MMAP_FILE_ACCESS_READ_EXECUTE = 4,
+ MMAP_FILE_ACCESS_READ_WRITE_EXECUTE = 5,
+};
+
+static DWORD get_page_access (int access)
+{
+ switch (access) {
+ case MMAP_FILE_ACCESS_READ:
+ return PAGE_READONLY;
+ case MMAP_FILE_ACCESS_READ_WRITE:
+ return PAGE_READWRITE;
+ case MMAP_FILE_ACCESS_COPY_ON_WRITE:
+ return PAGE_WRITECOPY;
+ case MMAP_FILE_ACCESS_READ_EXECUTE:
+ return PAGE_EXECUTE_READ;
+ case MMAP_FILE_ACCESS_READ_WRITE_EXECUTE:
+ return PAGE_EXECUTE_READWRITE;
+ default:
+ g_error ("unknown MemoryMappedFileAccess %d", access);
+ }
+}
+
+static DWORD get_file_access (int access)
+{
+ switch (access) {
+ case MMAP_FILE_ACCESS_READ:
+ case MMAP_FILE_ACCESS_READ_EXECUTE:
+ return GENERIC_READ;
+ case MMAP_FILE_ACCESS_READ_WRITE:
+ case MMAP_FILE_ACCESS_COPY_ON_WRITE:
+ case MMAP_FILE_ACCESS_READ_WRITE_EXECUTE:
+ return GENERIC_READ | GENERIC_WRITE;
+ case MMAP_FILE_ACCESS_WRITE:
+ return GENERIC_WRITE;
+ default:
+ g_error ("unknown MemoryMappedFileAccess %d", access);
+ }
+}
+
+static int get_file_map_access (int access)
+{
+ switch (access) {
+ case MMAP_FILE_ACCESS_READ:
+ return FILE_MAP_READ;
+ case MMAP_FILE_ACCESS_WRITE:
+ return FILE_MAP_WRITE;
+ case MMAP_FILE_ACCESS_READ_WRITE:
+ return FILE_MAP_READ | FILE_MAP_WRITE;
+ case MMAP_FILE_ACCESS_COPY_ON_WRITE:
+ return FILE_MAP_COPY;
+ case MMAP_FILE_ACCESS_READ_EXECUTE:
+ return FILE_MAP_EXECUTE | FILE_MAP_READ;
+ case MMAP_FILE_ACCESS_READ_WRITE_EXECUTE:
+ return FILE_MAP_EXECUTE | FILE_MAP_READ | FILE_MAP_WRITE;
+ default:
+ g_error ("unknown MemoryMappedFileAccess %d", access);
+ }
+}
+
+static int convert_win32_error (int error, int def)
+{
+ switch (error) {
+ case ERROR_FILE_NOT_FOUND:
+ return FILE_NOT_FOUND;
+ case ERROR_FILE_EXISTS:
+ case ERROR_ALREADY_EXISTS:
+ return FILE_ALREADY_EXISTS;
+ case ERROR_ACCESS_DENIED:
+ return ACCESS_DENIED;
+ }
+ return def;
+}
+
+static void *open_handle (void *handle, MonoString *mapName, int mode, gint64 *capacity, int access, int options, int *error)
{
- g_error ("No windows backend");
- return NULL;
+ g_assert (handle != NULL);
+
+ wchar_t *w_mapName = NULL;
+ HANDLE result = NULL;
+
+ if (handle == INVALID_HANDLE_VALUE) {
+ if (*capacity <= 0 && mode != FILE_MODE_OPEN) {
+ *error = CAPACITY_MUST_BE_POSITIVE;
+ return NULL;
+ }
+#if SIZEOF_VOID_P == 4
+ if (*capacity > UINT32_MAX) {
+ *error = CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE;
+ return NULL;
+ }
+#endif
+ if (!(mode == FILE_MODE_CREATE_NEW || mode == FILE_MODE_OPEN_OR_CREATE || mode == FILE_MODE_OPEN)) {
+ *error = INVALID_FILE_MODE;
+ return NULL;
+ }
+ } else {
+ FILE_STANDARD_INFO info;
+ if (!GetFileInformationByHandleEx ((HANDLE) handle, FileStandardInfo, &info, sizeof (FILE_STANDARD_INFO))) {
+ *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
+ return NULL;
+ }
+ if (*capacity == 0) {
+ if (info.EndOfFile.QuadPart == 0) {
+ *error = CAPACITY_SMALLER_THAN_FILE_SIZE;
+ return NULL;
+ }
+ } else if (*capacity < info.EndOfFile.QuadPart) {
+ *error = CAPACITY_SMALLER_THAN_FILE_SIZE;
+ return NULL;
+ }
+ }
+
+ w_mapName = mapName ? mono_string_to_utf16 (mapName) : NULL;
+
+ if (mode == FILE_MODE_CREATE_NEW || handle != INVALID_HANDLE_VALUE) {
+ result = CreateFileMappingW ((HANDLE)handle, NULL, get_page_access (access) | options, (DWORD)(((guint64)*capacity) >> 32), (DWORD)*capacity, w_mapName);
+ if (result && GetLastError () == ERROR_ALREADY_EXISTS) {
+ CloseHandle (result);
+ result = NULL;
+ *error = FILE_ALREADY_EXISTS;
+ } else if (!result && GetLastError () != NO_ERROR) {
+ *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
+ }
+ } else if (mode == FILE_MODE_OPEN || mode == FILE_MODE_OPEN_OR_CREATE && access == MMAP_FILE_ACCESS_WRITE) {
+ result = OpenFileMappingW (get_file_map_access (access), FALSE, w_mapName);
+ if (!result) {
+ if (mode == FILE_MODE_OPEN_OR_CREATE && GetLastError () == ERROR_FILE_NOT_FOUND) {
+ *error = INVALID_FILE_MODE;
+ } else {
+ *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
+ }
+ }
+ } else if (mode == FILE_MODE_OPEN_OR_CREATE) {
+
+ // This replicates how CoreFX does MemoryMappedFile.CreateOrOpen ().
+
+ /// Try to open the file if it exists -- this requires a bit more work. Loop until we can
+ /// either create or open a memory mapped file up to a timeout. CreateFileMapping may fail
+ /// if the file exists and we have non-null security attributes, in which case we need to
+ /// use OpenFileMapping. But, there exists a race condition because the memory mapped file
+ /// may have closed between the two calls -- hence the loop.
+ ///
+ /// The retry/timeout logic increases the wait time each pass through the loop and times
+ /// out in approximately 1.4 minutes. If after retrying, a MMF handle still hasn't been opened,
+ /// throw an InvalidOperationException.
+
+ guint32 waitRetries = 14; //((2^13)-1)*10ms == approximately 1.4mins
+ guint32 waitSleep = 0;
+
+ while (waitRetries > 0) {
+ result = CreateFileMappingW ((HANDLE)handle, NULL, get_page_access (access) | options, (DWORD)(((guint64)*capacity) >> 32), (DWORD)*capacity, w_mapName);
+ if (result)
+ break;
+ if (GetLastError() != ERROR_ACCESS_DENIED) {
+ *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
+ break;
+ }
+ result = OpenFileMappingW (get_file_map_access (access), FALSE, w_mapName);
+ if (result)
+ break;
+ if (GetLastError () != ERROR_FILE_NOT_FOUND) {
+ *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
+ break;
+ }
+ // increase wait time
+ --waitRetries;
+ if (waitSleep == 0) {
+ waitSleep = 10;
+ } else {
+ mono_thread_info_sleep (waitSleep, NULL);
+ waitSleep *= 2;
+ }
+ }
+
+ if (!result) {
+ *error = COULD_NOT_OPEN;
+ }
+ }
+
+ if (w_mapName)
+ g_free (w_mapName);
+ return result;
}
-void *
-mono_mmap_open_handle (void *handle, MonoString *mapName, gint64 *capacity, int access, int options, int *error)
+void *mono_mmap_open_file (MonoString *path, int mode, MonoString *mapName, gint64 *capacity, int access, int options, int *error)
{
- g_error ("No windows backend");
- return NULL;
+ g_assert (path != NULL || mapName != NULL);
+
+ wchar_t *w_path = NULL;
+ HANDLE hFile = INVALID_HANDLE_VALUE;
+ HANDLE result = NULL;
+ gboolean delete_on_error = FALSE;
+
+ if (path) {
+ w_path = mono_string_to_utf16 (path);
+ WIN32_FILE_ATTRIBUTE_DATA file_attrs;
+ gboolean existed = GetFileAttributesExW (w_path, GetFileExInfoStandard, &file_attrs);
+ if (!existed && mode == FILE_MODE_CREATE_NEW && *capacity == 0) {
+ *error = CAPACITY_SMALLER_THAN_FILE_SIZE;
+ goto done;
+ }
+ hFile = CreateFileW (w_path, get_file_access (access), FILE_SHARE_READ, NULL, mode, FILE_ATTRIBUTE_NORMAL, NULL);
+ if (hFile == INVALID_HANDLE_VALUE) {
+ *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
+ goto done;
+ }
+ delete_on_error = !existed;
+ }
+
+ result = open_handle (hFile, mapName, mode, capacity, access, options, error);
+
+done:
+ if (hFile != INVALID_HANDLE_VALUE)
+ CloseHandle (hFile);
+ if (!result && delete_on_error)
+ DeleteFileW (w_path);
+ if (w_path)
+ g_free (w_path);
+
+ return result;
}
-void
-mono_mmap_close (void *mmap_handle)
+void *mono_mmap_open_handle (void *handle, MonoString *mapName, gint64 *capacity, int access, int options, int *error)
{
- g_error ("No windows backend");
+ g_assert (handle != NULL);
+
+ return open_handle (handle, mapName, FILE_MODE_OPEN, capacity, access, options, error);
}
-void
-mono_mmap_configure_inheritability (void *mmap_handle, gboolean inheritability)
+void mono_mmap_close (void *mmap_handle)
{
- g_error ("No windows backend");
+ g_assert (mmap_handle);
+ CloseHandle ((HANDLE) mmap_handle);
}
-void
-mono_mmap_flush (void *mmap_handle)
+void mono_mmap_configure_inheritability (void *mmap_handle, gboolean inheritability)
{
- g_error ("No windows backend");
+ g_assert (mmap_handle);
+ if (!SetHandleInformation ((HANDLE) mmap_handle, HANDLE_FLAG_INHERIT, inheritability ? HANDLE_FLAG_INHERIT : 0)) {
+ g_error ("mono_mmap_configure_inheritability: SetHandleInformation failed with error %d!", GetLastError ());
+ }
}
+void mono_mmap_flush (void *mmap_handle)
+{
+ g_assert (mmap_handle);
+ MmapInstance *h = (MmapInstance *)mmap_handle;
+
+ if (FlushViewOfFile (h->address, h->length))
+ return;
+
+ // This replicates how CoreFX does MemoryMappedView.Flush ().
+
+ // It is a known issue within the NTFS transaction log system that
+ // causes FlushViewOfFile to intermittently fail with ERROR_LOCK_VIOLATION
+ // As a workaround, we catch this particular error and retry the flush operation
+ // a few milliseconds later. If it does not work, we give it a few more tries with
+ // increasing intervals. Eventually, however, we need to give up. In ad-hoc tests
+ // this strategy successfully flushed the view after no more than 3 retries.
+
+ if (GetLastError () != ERROR_LOCK_VIOLATION)
+ // TODO: Propagate error to caller
+ return;
+
+ for (int w = 0; w < MAX_FLUSH_WAITS; w++) {
+ int pause = (1 << w); // MaxFlushRetries should never be over 30
+ mono_thread_info_sleep (pause, NULL);
+
+ for (int r = 0; r < MAX_FLUSH_RETIRES_PER_WAIT; r++) {
+ if (FlushViewOfFile (h->address, h->length))
+ return;
+ if (GetLastError () != ERROR_LOCK_VIOLATION)
+ // TODO: Propagate error to caller
+ return;
-int
-mono_mmap_map (void *handle, gint64 offset, gint64 *size, int access, void **mmap_handle, void **base_address)
+ mono_thread_info_yield ();
+ }
+ }
+
+ // We got to here, so there was no success:
+ // TODO: Propagate error to caller
+}
+
+int mono_mmap_map (void *handle, gint64 offset, gint64 *size, int access, void **mmap_handle, void **base_address)
{
- g_error ("No windows backend");
+ static DWORD allocationGranularity = 0;
+ if (allocationGranularity == 0) {
+ SYSTEM_INFO info;
+ GetSystemInfo (&info);
+ allocationGranularity = info.dwAllocationGranularity;
+ }
+
+ gint64 extraMemNeeded = offset % allocationGranularity;
+ guint64 newOffset = offset - extraMemNeeded;
+ gint64 nativeSize = (*size != 0) ? *size + extraMemNeeded : 0;
+
+#if SIZEOF_VOID_P == 4
+ if (nativeSize > UINT32_MAX)
+ return CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE;
+#endif
+
+ void *address = MapViewOfFile ((HANDLE) handle, get_file_map_access (access), (DWORD) (newOffset >> 32), (DWORD) newOffset, (SIZE_T) nativeSize);
+ if (!address)
+ return convert_win32_error (GetLastError (), COULD_NOT_MAP_MEMORY);
+
+ // Query the view for its size and allocation type
+ MEMORY_BASIC_INFORMATION viewInfo;
+ VirtualQuery (address, &viewInfo, sizeof (MEMORY_BASIC_INFORMATION));
+ guint64 viewSize = (guint64) viewInfo.RegionSize;
+
+ // Allocate the pages if we were using the MemoryMappedFileOptions.DelayAllocatePages option
+ // OR check if the allocated view size is smaller than the expected native size
+ // If multiple overlapping views are created over the file mapping object, the pages in a given region
+ // could have different attributes(MEM_RESERVE OR MEM_COMMIT) as MapViewOfFile preserves coherence between
+ // views created on a mapping object backed by same file.
+ // In which case, the viewSize will be smaller than nativeSize required and viewState could be MEM_COMMIT
+ // but more pages may need to be committed in the region.
+ // This is because, VirtualQuery function(that internally invokes VirtualQueryEx function) returns the attributes
+ // and size of the region of pages with matching attributes starting from base address.
+ // VirtualQueryEx: http://msdn.microsoft.com/en-us/library/windows/desktop/aa366907(v=vs.85).aspx
+ if (((viewInfo.State & MEM_RESERVE) != 0) || viewSize < (guint64) nativeSize) {
+ void *tempAddress = VirtualAlloc (address, nativeSize != 0 ? nativeSize : viewSize, MEM_COMMIT, get_page_access (access));
+ if (!tempAddress) {
+ return convert_win32_error (GetLastError (), COULD_NOT_MAP_MEMORY);
+ }
+ // again query the view for its new size
+ VirtualQuery (address, &viewInfo, sizeof (MEMORY_BASIC_INFORMATION));
+ viewSize = (guint64) viewInfo.RegionSize;
+ }
+
+ if (*size == 0)
+ *size = viewSize - extraMemNeeded;
+
+ MmapInstance *h = g_malloc0 (sizeof (MmapInstance));
+ h->address = address;
+ h->length = *size + extraMemNeeded;
+ *mmap_handle = h;
+ *base_address = (char*) address + (offset - newOffset);
+
return 0;
}
-gboolean
-mono_mmap_unmap (void *mmap_handle)
+gboolean mono_mmap_unmap (void *mmap_handle)
{
- g_error ("No windows backend");
- return TRUE;
+ g_assert (mmap_handle);
+
+ MmapInstance *h = (MmapInstance *) mmap_handle;
+
+ gboolean result = UnmapViewOfFile (h->address);
+
+ g_free (h);
+ return result;
}
+#else
+
+MONO_EMPTY_SOURCE_FILE (file_mmap_windows);
+
#endif
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