mono/metadata/file-mmap-windows.c

   1 /**
   2  * \file
   3  * MemoryMappedFile internal calls for Windows
   4  *
   5  * Copyright 2016 Microsoft
   6  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   7  */
   8
   9 /*
  10  * The code in this file has been inspired by the CoreFX MemoryMappedFile Windows implementation contained in the files
  11  *
  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
  14  */
  15
  16 #include <config.h>
  17 #include <glib.h>
  18 #include <mono/utils/mono-compiler.h>
  19 #if G_HAVE_API_SUPPORT(HAVE_CLASSIC_WINAPI_SUPPORT) && defined(HOST_WIN32)
  20
  21 #include <glib.h>
  22
  23 #include <mono/metadata/file-mmap.h>
  24
  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
  28
  29 typedef struct {
  30         void *address;
  31         size_t length;
  32 } MmapInstance;
  33
  34 enum {
  35         BAD_CAPACITY_FOR_FILE_BACKED = 1,
  36         CAPACITY_SMALLER_THAN_FILE_SIZE,
  37         FILE_NOT_FOUND,
  38         FILE_ALREADY_EXISTS,
  39         PATH_TOO_LONG,
  40         COULD_NOT_OPEN,
  41         CAPACITY_MUST_BE_POSITIVE,
  42         INVALID_FILE_MODE,
  43         COULD_NOT_MAP_MEMORY,
  44         ACCESS_DENIED,
  45         CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE
  46 };
  47
  48 enum {
  49         FILE_MODE_CREATE_NEW = 1,
  50         FILE_MODE_CREATE = 2,
  51         FILE_MODE_OPEN = 3,
  52         FILE_MODE_OPEN_OR_CREATE = 4,
  53         FILE_MODE_TRUNCATE = 5,
  54         FILE_MODE_APPEND = 6,
  55 };
  56
  57 enum {
  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,
  64 };
  65
  66 static DWORD get_page_access (int access)
  67 {
  68         switch (access) {
  69         case MMAP_FILE_ACCESS_READ:
  70                 return PAGE_READONLY;
  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;
  79         default:
  80                 g_error ("unknown MemoryMappedFileAccess %d", access);
  81         }
  82 }
  83
  84 static DWORD get_file_access (int access)
  85 {
  86         switch (access) {
  87         case MMAP_FILE_ACCESS_READ:
  88         case MMAP_FILE_ACCESS_READ_EXECUTE:
  89                 return GENERIC_READ;
  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:
  95                 return GENERIC_WRITE;
  96         default:
  97                 g_error ("unknown MemoryMappedFileAccess %d", access);
  98         }
  99 }
 100
 101 static int get_file_map_access (int access)
 102 {
 103         switch (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;
 116         default:
 117                 g_error ("unknown MemoryMappedFileAccess %d", access);
 118         }
 119 }
 120
 121 static int convert_win32_error (int win32error, int default_)
 122 {
 123         switch (win32error) {
 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;
 131         }
 132         return default_;
 133 }
 134
 135 static void*
 136 open_handle (void *handle, const gunichar2 *mapName, gint mapName_length, int mode, gint64 *capacity, int access, int options, int *ioerror, MonoError *error)
 137 {
 138         g_assert (handle != NULL);
 139
 140         // INVALID_HANDLE_VALUE (-1) is valid, to make named shared memory,
 141         // backed by physical memory / pagefile.
 142
 143         if (handle == INVALID_HANDLE_VALUE) {
 144                 if (*capacity <= 0 && mode != FILE_MODE_OPEN) {
 145                         *ioerror = CAPACITY_MUST_BE_POSITIVE;
 146                         return NULL;
 147                 }
 148 #if SIZEOF_VOID_P == 4
 149                 if (*capacity > UINT32_MAX) {
 150                         *ioerror = CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE;
 151                         return NULL;
 152                 }
 153 #endif
 154                 if (!(mode == FILE_MODE_CREATE_NEW || mode == FILE_MODE_OPEN_OR_CREATE || mode == FILE_MODE_OPEN)) {
 155                         *ioerror = INVALID_FILE_MODE;
 156                         return NULL;
 157                 }
 158         } else {
 159                 FILE_STANDARD_INFO info;
 160                 if (!GetFileInformationByHandleEx (handle, FileStandardInfo, &info, sizeof (FILE_STANDARD_INFO))) {
 161                         *ioerror = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
 162                         return NULL;
 163                 }
 164                 if (*capacity == 0) {
 165                         if (info.EndOfFile.QuadPart == 0) {
 166                                 *ioerror = CAPACITY_SMALLER_THAN_FILE_SIZE;
 167                                 return NULL;
 168                         }
 169                 } else if (*capacity < info.EndOfFile.QuadPart) {
 170                         *ioerror = CAPACITY_SMALLER_THAN_FILE_SIZE;
 171                         return NULL;
 172                 }
 173         }
 174
 175         HANDLE result = NULL;
 176
 177         if (mode == FILE_MODE_CREATE_NEW || handle != INVALID_HANDLE_VALUE) {
 178                 result = CreateFileMappingW (handle, NULL, get_page_access (access) | options, (DWORD)(((guint64)*capacity) >> 32), (DWORD)*capacity, mapName);
 179                 if (result && GetLastError () == ERROR_ALREADY_EXISTS) {
 180                         CloseHandle (result);
 181                         result = NULL;
 182                         *ioerror = FILE_ALREADY_EXISTS;
 183                 } else if (!result && GetLastError () != NO_ERROR) {
 184                         *ioerror = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
 185                 }
 186         } else if (mode == FILE_MODE_OPEN || mode == FILE_MODE_OPEN_OR_CREATE && access == MMAP_FILE_ACCESS_WRITE) {
 187                 result = OpenFileMappingW (get_file_map_access (access), FALSE, mapName);
 188                 if (!result) {
 189                         if (mode == FILE_MODE_OPEN_OR_CREATE && GetLastError () == ERROR_FILE_NOT_FOUND) {
 190                                 *ioerror = INVALID_FILE_MODE;
 191                         } else {
 192                                 *ioerror = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
 193                         }
 194                 }
 195         } else if (mode == FILE_MODE_OPEN_OR_CREATE) {
 196
 197                 // This replicates how CoreFX does MemoryMappedFile.CreateOrOpen ().
 198
 199                 /// Try to open the file if it exists -- this requires a bit more work. Loop until we can
 200                 /// either create or open a memory mapped file up to a timeout. CreateFileMapping may fail
 201                 /// if the file exists and we have non-null security attributes, in which case we need to
 202                 /// use OpenFileMapping.  But, there exists a race condition because the memory mapped file
 203                 /// may have closed between the two calls -- hence the loop.
 204                 ///
 205                 /// The retry/timeout logic increases the wait time each pass through the loop and times
 206                 /// out in approximately 1.4 minutes. If after retrying, a MMF handle still hasn't been opened,
 207                 /// throw an InvalidOperationException.
 208
 209                 guint32 waitRetries = 14;   //((2^13)-1)*10ms == approximately 1.4mins
 210                 guint32 waitSleep = 0;
 211
 212                 while (waitRetries > 0) {
 213                         result = CreateFileMappingW (handle, NULL, get_page_access (access) | options, (DWORD)(((guint64)*capacity) >> 32), (DWORD)*capacity, mapName);
 214                         if (result)
 215                                 break;
 216                         if (GetLastError() != ERROR_ACCESS_DENIED) {
 217                                 *ioerror = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
 218                                 break;
 219                         }
 220                         result = OpenFileMappingW (get_file_map_access (access), FALSE, mapName);
 221                         if (result)
 222                                 break;
 223                         if (GetLastError () != ERROR_FILE_NOT_FOUND) {
 224                                 *ioerror = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
 225                                 break;
 226                         }
 227                         // increase wait time
 228                         --waitRetries;
 229                         if (waitSleep == 0) {
 230                                 waitSleep = 10;
 231                         } else {
 232                                 mono_thread_info_sleep (waitSleep, NULL);
 233                                 waitSleep *= 2;
 234                         }
 235                 }
 236
 237                 if (!result) {
 238                         *ioerror = COULD_NOT_OPEN;
 239                 }
 240         }
 241
 242         return result;
 243 }
 244
 245 void*
 246 mono_mmap_open_file (const gunichar2 *path, gint path_length, int mode, const gunichar2 *mapName, gint mapName_length, gint64 *capacity, int access, int options, int *ioerror, MonoError *error)
 247 {
 248         g_assert (path != NULL || mapName != NULL);
 249
 250         HANDLE hFile = INVALID_HANDLE_VALUE;
 251         HANDLE result = NULL;
 252         gboolean delete_on_error = FALSE;
 253
 254         if (path) {
 255                 WIN32_FILE_ATTRIBUTE_DATA file_attrs;
 256                 gboolean existed = GetFileAttributesExW (path, GetFileExInfoStandard, &file_attrs);
 257                 if (!existed && mode == FILE_MODE_CREATE_NEW && *capacity == 0) {
 258                         *ioerror = CAPACITY_SMALLER_THAN_FILE_SIZE;
 259                         goto done;
 260                 }
 261                 hFile = CreateFileW (path, get_file_access (access), FILE_SHARE_READ, NULL, mode, FILE_ATTRIBUTE_NORMAL, NULL);
 262                 if (hFile == INVALID_HANDLE_VALUE) {
 263                         *ioerror = convert_win32_error (GetLastError (), COULD_NOT_OPEN);
 264                         goto done;
 265                 }
 266                 delete_on_error = !existed;
 267         } else {
 268                 // INVALID_HANDLE_VALUE (-1) is valid, to make named shared memory,
 269                 // backed by physical memory / pagefile.
 270         }
 271
 272         result = open_handle (hFile, mapName, mapName_length, mode, capacity, access, options, ioerror, error);
 273
 274 done:
 275         if (hFile != INVALID_HANDLE_VALUE)
 276                 CloseHandle (hFile);
 277         if (!result && delete_on_error)
 278                 DeleteFileW (path);
 279
 280         return result;
 281 }
 282
 283 void*
 284 mono_mmap_open_handle (void *handle, const gunichar2 *mapName, gint mapName_length, gint64 *capacity, int access, int options, int *ioerror, MonoError *error)
 285 {
 286         g_assert (handle != NULL);
 287
 288         return open_handle (handle, mapName, mapName_length, FILE_MODE_OPEN, capacity, access, options, ioerror, error);
 289 }
 290
 291 void
 292 mono_mmap_close (void *mmap_handle, MonoError *error)
 293 {
 294         g_assert (mmap_handle);
 295         CloseHandle (mmap_handle);
 296 }
 297
 298 void
 299 mono_mmap_configure_inheritability (void *mmap_handle, gint32 inheritability, MonoError *error)
 300 {
 301         g_assert (mmap_handle);
 302         if (!SetHandleInformation (mmap_handle, HANDLE_FLAG_INHERIT, inheritability ? HANDLE_FLAG_INHERIT : 0)) {
 303                 g_error ("mono_mmap_configure_inheritability: SetHandleInformation failed with error %d!", GetLastError ());
 304         }
 305 }
 306
 307 void
 308 mono_mmap_flush (void *mmap_handle, MonoError *error)
 309 {
 310         g_assert (mmap_handle);
 311         MmapInstance *h = (MmapInstance *)mmap_handle;
 312
 313         if (FlushViewOfFile (h->address, h->length))
 314                 return;
 315
 316         // This replicates how CoreFX does MemoryMappedView.Flush ().
 317
 318         // It is a known issue within the NTFS transaction log system that
 319         // causes FlushViewOfFile to intermittently fail with ERROR_LOCK_VIOLATION
 320         // As a workaround, we catch this particular error and retry the flush operation
 321         // a few milliseconds later. If it does not work, we give it a few more tries with
 322         // increasing intervals. Eventually, however, we need to give up. In ad-hoc tests
 323         // this strategy successfully flushed the view after no more than 3 retries.
 324
 325         if (GetLastError () != ERROR_LOCK_VIOLATION)
 326                 // TODO: Propagate error to caller
 327                 return;
 328
 329         for (int w = 0; w < MAX_FLUSH_WAITS; w++) {
 330                 int pause = (1 << w);  // MaxFlushRetries should never be over 30
 331                 mono_thread_info_sleep (pause, NULL);
 332
 333                 for (int r = 0; r < MAX_FLUSH_RETIRES_PER_WAIT; r++) {
 334                         if (FlushViewOfFile (h->address, h->length))
 335                                 return;
 336
 337                         if (GetLastError () != ERROR_LOCK_VIOLATION)
 338                                 // TODO: Propagate error to caller
 339                                 return;
 340
 341                         mono_thread_info_yield ();
 342                 }
 343         }
 344
 345         // We got to here, so there was no success:
 346         // TODO: Propagate error to caller
 347 }
 348
 349 int
 350 mono_mmap_map (void *handle, gint64 offset, gint64 *size, int access, void **mmap_handle, void **base_address, MonoError *error)
 351 {
 352         static DWORD allocationGranularity = 0;
 353         if (allocationGranularity == 0) {
 354                 SYSTEM_INFO info;
 355                 GetSystemInfo (&info);
 356                 allocationGranularity = info.dwAllocationGranularity;
 357         }
 358
 359         gint64 extraMemNeeded = offset % allocationGranularity;
 360         guint64 newOffset = offset - extraMemNeeded;
 361         gint64 nativeSize = (*size != 0) ? *size + extraMemNeeded : 0;
 362
 363 #if SIZEOF_VOID_P == 4
 364         if (nativeSize > UINT32_MAX)
 365                 return CAPACITY_LARGER_THAN_LOGICAL_ADDRESS_SPACE;
 366 #endif
 367
 368         void *address = MapViewOfFile (handle, get_file_map_access (access), (DWORD) (newOffset >> 32), (DWORD) newOffset, (SIZE_T) nativeSize);
 369         if (!address)
 370                 return convert_win32_error (GetLastError (), COULD_NOT_MAP_MEMORY);
 371
 372         // Query the view for its size and allocation type
 373         MEMORY_BASIC_INFORMATION viewInfo;
 374         VirtualQuery (address, &viewInfo, sizeof (MEMORY_BASIC_INFORMATION));
 375         guint64 viewSize = (guint64) viewInfo.RegionSize;
 376
 377         // Allocate the pages if we were using the MemoryMappedFileOptions.DelayAllocatePages option
 378         // OR check if the allocated view size is smaller than the expected native size
 379         // If multiple overlapping views are created over the file mapping object, the pages in a given region
 380         // could have different attributes(MEM_RESERVE OR MEM_COMMIT) as MapViewOfFile preserves coherence between
 381         // views created on a mapping object backed by same file.
 382         // In which case, the viewSize will be smaller than nativeSize required and viewState could be MEM_COMMIT
 383         // but more pages may need to be committed in the region.
 384         // This is because, VirtualQuery function(that internally invokes VirtualQueryEx function) returns the attributes
 385         // and size of the region of pages with matching attributes starting from base address.
 386         // VirtualQueryEx: http://msdn.microsoft.com/en-us/library/windows/desktop/aa366907(v=vs.85).aspx
 387         if (((viewInfo.State & MEM_RESERVE) != 0) || viewSize < (guint64) nativeSize) {
 388                 void *tempAddress = VirtualAlloc (address, nativeSize != 0 ? nativeSize : viewSize, MEM_COMMIT, get_page_access (access));
 389                 if (!tempAddress) {
 390                         return convert_win32_error (GetLastError (), COULD_NOT_MAP_MEMORY);
 391                 }
 392                 // again query the view for its new size
 393                 VirtualQuery (address, &viewInfo, sizeof (MEMORY_BASIC_INFORMATION));
 394                 viewSize = (guint64) viewInfo.RegionSize;
 395         }
 396
 397         if (*size == 0)
 398                 *size = viewSize - extraMemNeeded;
 399
 400         MmapInstance *h = g_malloc0 (sizeof (MmapInstance));
 401         h->address = address;
 402         h->length = *size + extraMemNeeded;
 403         *mmap_handle = h;
 404         *base_address = (char*) address + (offset - newOffset);
 405
 406         return 0;
 407 }
 408
 409 MonoBoolean
 410 mono_mmap_unmap (void *mmap_handle, MonoError *error)
 411 {
 412         g_assert (mmap_handle);
 413
 414         MmapInstance *h = (MmapInstance *) mmap_handle;
 415
 416         gboolean result = UnmapViewOfFile (h->address);
 417
 418         g_free (h);
 419         return result;
 420 }
 421
 422 #else
 423
 424 MONO_EMPTY_SOURCE_FILE (file_mmap_windows);
 425
 426 #endif