3 * MemoryMappedFile internal calls for Windows
5 * Copyright 2016 Microsoft
6 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
10 * The code in this file has been inspired by the CoreFX MemoryMappedFile Windows implementation contained in the files
12 * https://github.com/dotnet/corefx/blob/master/src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedFile.Windows.cs
13 * https://github.com/dotnet/corefx/blob/master/src/System.IO.MemoryMappedFiles/src/System/IO/MemoryMappedFiles/MemoryMappedView.Windows.cs
18 #include <mono/utils/mono-compiler.h>
19 #if G_HAVE_API_SUPPORT(HAVE_CLASSIC_WINAPI_SUPPORT) && defined(HOST_WIN32)
23 #include <mono/metadata/file-mmap.h>
25 // These control the retry behaviour when lock violation errors occur during Flush:
26 #define MAX_FLUSH_WAITS 15 // must be <=30
27 #define MAX_FLUSH_RETIRES_PER_WAIT 20
35 BAD_CAPACITY_FOR_FILE_BACKED = 1,
36 CAPACITY_SMALLER_THAN_FILE_SIZE,
41 CAPACITY_MUST_BE_POSITIVE,
45 CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE
49 FILE_MODE_CREATE_NEW = 1,
52 FILE_MODE_OPEN_OR_CREATE = 4,
53 FILE_MODE_TRUNCATE = 5,
58 MMAP_FILE_ACCESS_READ_WRITE = 0,
59 MMAP_FILE_ACCESS_READ = 1,
60 MMAP_FILE_ACCESS_WRITE = 2,
61 MMAP_FILE_ACCESS_COPY_ON_WRITE = 3,
62 MMAP_FILE_ACCESS_READ_EXECUTE = 4,
63 MMAP_FILE_ACCESS_READ_WRITE_EXECUTE = 5,
66 static DWORD get_page_access (int access)
69 case MMAP_FILE_ACCESS_READ:
71 case MMAP_FILE_ACCESS_READ_WRITE:
72 return PAGE_READWRITE;
73 case MMAP_FILE_ACCESS_COPY_ON_WRITE:
74 return PAGE_WRITECOPY;
75 case MMAP_FILE_ACCESS_READ_EXECUTE:
76 return PAGE_EXECUTE_READ;
77 case MMAP_FILE_ACCESS_READ_WRITE_EXECUTE:
78 return PAGE_EXECUTE_READWRITE;
80 g_error ("unknown MemoryMappedFileAccess %d", access);
84 static DWORD get_file_access (int access)
87 case MMAP_FILE_ACCESS_READ:
88 case MMAP_FILE_ACCESS_READ_EXECUTE:
90 case MMAP_FILE_ACCESS_READ_WRITE:
91 case MMAP_FILE_ACCESS_COPY_ON_WRITE:
92 case MMAP_FILE_ACCESS_READ_WRITE_EXECUTE:
93 return GENERIC_READ | GENERIC_WRITE;
94 case MMAP_FILE_ACCESS_WRITE:
97 g_error ("unknown MemoryMappedFileAccess %d", access);
101 static int get_file_map_access (int access)
104 case MMAP_FILE_ACCESS_READ:
105 return FILE_MAP_READ;
106 case MMAP_FILE_ACCESS_WRITE:
107 return FILE_MAP_WRITE;
108 case MMAP_FILE_ACCESS_READ_WRITE:
109 return FILE_MAP_READ | FILE_MAP_WRITE;
110 case MMAP_FILE_ACCESS_COPY_ON_WRITE:
111 return FILE_MAP_COPY;
112 case MMAP_FILE_ACCESS_READ_EXECUTE:
113 return FILE_MAP_EXECUTE | FILE_MAP_READ;
114 case MMAP_FILE_ACCESS_READ_WRITE_EXECUTE:
115 return FILE_MAP_EXECUTE | FILE_MAP_READ | FILE_MAP_WRITE;
117 g_error ("unknown MemoryMappedFileAccess %d", access);
121 static int convert_win32_error (int error, int def)
124 case ERROR_FILE_NOT_FOUND:
125 return FILE_NOT_FOUND;
126 case ERROR_FILE_EXISTS:
127 case ERROR_ALREADY_EXISTS:
128 return FILE_ALREADY_EXISTS;
129 case ERROR_ACCESS_DENIED:
130 return ACCESS_DENIED;
135 static void *open_handle (void *handle, MonoString *mapName, int mode, gint64 *capacity, int access, int options, int *error)
137 g_assert (handle != NULL);
139 wchar_t *w_mapName = NULL;
140 HANDLE result = NULL;
142 if (handle == INVALID_HANDLE_VALUE) {
143 if (*capacity <= 0 && mode != FILE_MODE_OPEN) {
144 *error = CAPACITY_MUST_BE_POSITIVE;
147 #if SIZEOF_VOID_P == 4
148 if (*capacity > UINT32_MAX) {
149 *error = CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE;
153 if (!(mode == FILE_MODE_CREATE_NEW || mode == FILE_MODE_OPEN_OR_CREATE || mode == FILE_MODE_OPEN)) {
154 *error = INVALID_FILE_MODE;
158 FILE_STANDARD_INFO info;
159 if (!GetFileInformationByHandleEx ((HANDLE) handle, FileStandardInfo, &info, sizeof (FILE_STANDARD_INFO))) {
160 *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
163 if (*capacity == 0) {
164 if (info.EndOfFile.QuadPart == 0) {
165 *error = CAPACITY_SMALLER_THAN_FILE_SIZE;
168 } else if (*capacity < info.EndOfFile.QuadPart) {
169 *error = CAPACITY_SMALLER_THAN_FILE_SIZE;
174 w_mapName = mapName ? mono_string_to_utf16 (mapName) : NULL;
176 if (mode == FILE_MODE_CREATE_NEW || handle != INVALID_HANDLE_VALUE) {
177 result = CreateFileMappingW ((HANDLE)handle, NULL, get_page_access (access) | options, (DWORD)(((guint64)*capacity) >> 32), (DWORD)*capacity, w_mapName);
178 if (result && GetLastError () == ERROR_ALREADY_EXISTS) {
179 CloseHandle (result);
181 *error = FILE_ALREADY_EXISTS;
182 } else if (!result && GetLastError () != NO_ERROR) {
183 *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
185 } else if (mode == FILE_MODE_OPEN || mode == FILE_MODE_OPEN_OR_CREATE && access == MMAP_FILE_ACCESS_WRITE) {
186 result = OpenFileMappingW (get_file_map_access (access), FALSE, w_mapName);
188 if (mode == FILE_MODE_OPEN_OR_CREATE && GetLastError () == ERROR_FILE_NOT_FOUND) {
189 *error = INVALID_FILE_MODE;
191 *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
194 } else if (mode == FILE_MODE_OPEN_OR_CREATE) {
196 // This replicates how CoreFX does MemoryMappedFile.CreateOrOpen ().
198 /// Try to open the file if it exists -- this requires a bit more work. Loop until we can
199 /// either create or open a memory mapped file up to a timeout. CreateFileMapping may fail
200 /// if the file exists and we have non-null security attributes, in which case we need to
201 /// use OpenFileMapping. But, there exists a race condition because the memory mapped file
202 /// may have closed between the two calls -- hence the loop.
204 /// The retry/timeout logic increases the wait time each pass through the loop and times
205 /// out in approximately 1.4 minutes. If after retrying, a MMF handle still hasn't been opened,
206 /// throw an InvalidOperationException.
208 guint32 waitRetries = 14; //((2^13)-1)*10ms == approximately 1.4mins
209 guint32 waitSleep = 0;
211 while (waitRetries > 0) {
212 result = CreateFileMappingW ((HANDLE)handle, NULL, get_page_access (access) | options, (DWORD)(((guint64)*capacity) >> 32), (DWORD)*capacity, w_mapName);
215 if (GetLastError() != ERROR_ACCESS_DENIED) {
216 *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
219 result = OpenFileMappingW (get_file_map_access (access), FALSE, w_mapName);
222 if (GetLastError () != ERROR_FILE_NOT_FOUND) {
223 *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
226 // increase wait time
228 if (waitSleep == 0) {
231 mono_thread_info_sleep (waitSleep, NULL);
237 *error = COULD_NOT_OPEN;
246 void *mono_mmap_open_file (MonoString *path, int mode, MonoString *mapName, gint64 *capacity, int access, int options, int *error)
248 g_assert (path != NULL || mapName != NULL);
250 wchar_t *w_path = NULL;
251 HANDLE hFile = INVALID_HANDLE_VALUE;
252 HANDLE result = NULL;
253 gboolean delete_on_error = FALSE;
256 w_path = mono_string_to_utf16 (path);
257 WIN32_FILE_ATTRIBUTE_DATA file_attrs;
258 gboolean existed = GetFileAttributesExW (w_path, GetFileExInfoStandard, &file_attrs);
259 if (!existed && mode == FILE_MODE_CREATE_NEW && *capacity == 0) {
260 *error = CAPACITY_SMALLER_THAN_FILE_SIZE;
263 hFile = CreateFileW (w_path, get_file_access (access), FILE_SHARE_READ, NULL, mode, FILE_ATTRIBUTE_NORMAL, NULL);
264 if (hFile == INVALID_HANDLE_VALUE) {
265 *error = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
268 delete_on_error = !existed;
271 result = open_handle (hFile, mapName, mode, capacity, access, options, error);
274 if (hFile != INVALID_HANDLE_VALUE)
276 if (!result && delete_on_error)
277 DeleteFileW (w_path);
284 void *mono_mmap_open_handle (void *handle, MonoString *mapName, gint64 *capacity, int access, int options, int *error)
286 g_assert (handle != NULL);
288 return open_handle (handle, mapName, FILE_MODE_OPEN, capacity, access, options, error);
291 void mono_mmap_close (void *mmap_handle)
293 g_assert (mmap_handle);
294 CloseHandle ((HANDLE) mmap_handle);
297 void mono_mmap_configure_inheritability (void *mmap_handle, gboolean inheritability)
299 g_assert (mmap_handle);
300 if (!SetHandleInformation ((HANDLE) mmap_handle, HANDLE_FLAG_INHERIT, inheritability ? HANDLE_FLAG_INHERIT : 0)) {
301 g_error ("mono_mmap_configure_inheritability: SetHandleInformation failed with error %d!", GetLastError ());
305 void mono_mmap_flush (void *mmap_handle)
307 g_assert (mmap_handle);
308 MmapInstance *h = (MmapInstance *)mmap_handle;
310 if (FlushViewOfFile (h->address, h->length))
313 // This replicates how CoreFX does MemoryMappedView.Flush ().
315 // It is a known issue within the NTFS transaction log system that
316 // causes FlushViewOfFile to intermittently fail with ERROR_LOCK_VIOLATION
317 // As a workaround, we catch this particular error and retry the flush operation
318 // a few milliseconds later. If it does not work, we give it a few more tries with
319 // increasing intervals. Eventually, however, we need to give up. In ad-hoc tests
320 // this strategy successfully flushed the view after no more than 3 retries.
322 if (GetLastError () != ERROR_LOCK_VIOLATION)
323 // TODO: Propagate error to caller
326 for (int w = 0; w < MAX_FLUSH_WAITS; w++) {
327 int pause = (1 << w); // MaxFlushRetries should never be over 30
328 mono_thread_info_sleep (pause, NULL);
330 for (int r = 0; r < MAX_FLUSH_RETIRES_PER_WAIT; r++) {
331 if (FlushViewOfFile (h->address, h->length))
334 if (GetLastError () != ERROR_LOCK_VIOLATION)
335 // TODO: Propagate error to caller
338 mono_thread_info_yield ();
342 // We got to here, so there was no success:
343 // TODO: Propagate error to caller
346 int mono_mmap_map (void *handle, gint64 offset, gint64 *size, int access, void **mmap_handle, void **base_address)
348 static DWORD allocationGranularity = 0;
349 if (allocationGranularity == 0) {
351 GetSystemInfo (&info);
352 allocationGranularity = info.dwAllocationGranularity;
355 gint64 extraMemNeeded = offset % allocationGranularity;
356 guint64 newOffset = offset - extraMemNeeded;
357 gint64 nativeSize = (*size != 0) ? *size + extraMemNeeded : 0;
359 #if SIZEOF_VOID_P == 4
360 if (nativeSize > UINT32_MAX)
361 return CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE;
364 void *address = MapViewOfFile ((HANDLE) handle, get_file_map_access (access), (DWORD) (newOffset >> 32), (DWORD) newOffset, (SIZE_T) nativeSize);
366 return convert_win32_error (GetLastError (), COULD_NOT_MAP_MEMORY);
368 // Query the view for its size and allocation type
369 MEMORY_BASIC_INFORMATION viewInfo;
370 VirtualQuery (address, &viewInfo, sizeof (MEMORY_BASIC_INFORMATION));
371 guint64 viewSize = (guint64) viewInfo.RegionSize;
373 // Allocate the pages if we were using the MemoryMappedFileOptions.DelayAllocatePages option
374 // OR check if the allocated view size is smaller than the expected native size
375 // If multiple overlapping views are created over the file mapping object, the pages in a given region
376 // could have different attributes(MEM_RESERVE OR MEM_COMMIT) as MapViewOfFile preserves coherence between
377 // views created on a mapping object backed by same file.
378 // In which case, the viewSize will be smaller than nativeSize required and viewState could be MEM_COMMIT
379 // but more pages may need to be committed in the region.
380 // This is because, VirtualQuery function(that internally invokes VirtualQueryEx function) returns the attributes
381 // and size of the region of pages with matching attributes starting from base address.
382 // VirtualQueryEx: http://msdn.microsoft.com/en-us/library/windows/desktop/aa366907(v=vs.85).aspx
383 if (((viewInfo.State & MEM_RESERVE) != 0) || viewSize < (guint64) nativeSize) {
384 void *tempAddress = VirtualAlloc (address, nativeSize != 0 ? nativeSize : viewSize, MEM_COMMIT, get_page_access (access));
386 return convert_win32_error (GetLastError (), COULD_NOT_MAP_MEMORY);
388 // again query the view for its new size
389 VirtualQuery (address, &viewInfo, sizeof (MEMORY_BASIC_INFORMATION));
390 viewSize = (guint64) viewInfo.RegionSize;
394 *size = viewSize - extraMemNeeded;
396 MmapInstance *h = g_malloc0 (sizeof (MmapInstance));
397 h->address = address;
398 h->length = *size + extraMemNeeded;
400 *base_address = (char*) address + (offset - newOffset);
405 gboolean mono_mmap_unmap (void *mmap_handle)
407 g_assert (mmap_handle);
409 MmapInstance *h = (MmapInstance *) mmap_handle;
411 gboolean result = UnmapViewOfFile (h->address);
419 MONO_EMPTY_SOURCE_FILE (file_mmap_windows);