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| 1 /* |
| 2 ** 2005 November 29 |
| 3 ** |
| 4 ** The author disclaims copyright to this source code. In place of |
| 5 ** a legal notice, here is a blessing: |
| 6 ** |
| 7 ** May you do good and not evil. |
| 8 ** May you find forgiveness for yourself and forgive others. |
| 9 ** May you share freely, never taking more than you give. |
| 10 ** |
| 11 ****************************************************************************** |
| 12 ** |
| 13 ** This file contains OS interface code that is common to all |
| 14 ** architectures. |
| 15 */ |
| 16 #define _SQLITE_OS_C_ 1 |
| 17 #include "sqliteInt.h" |
| 18 #undef _SQLITE_OS_C_ |
| 19 |
| 20 /* |
| 21 ** The default SQLite sqlite3_vfs implementations do not allocate |
| 22 ** memory (actually, os_unix.c allocates a small amount of memory |
| 23 ** from within OsOpen()), but some third-party implementations may. |
| 24 ** So we test the effects of a malloc() failing and the sqlite3OsXXX() |
| 25 ** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro. |
| 26 ** |
| 27 ** The following functions are instrumented for malloc() failure |
| 28 ** testing: |
| 29 ** |
| 30 ** sqlite3OsOpen() |
| 31 ** sqlite3OsRead() |
| 32 ** sqlite3OsWrite() |
| 33 ** sqlite3OsSync() |
| 34 ** sqlite3OsLock() |
| 35 ** |
| 36 */ |
| 37 #if defined(SQLITE_TEST) |
| 38 int sqlite3_memdebug_vfs_oom_test = 1; |
| 39 #define DO_OS_MALLOC_TEST(x) \ |
| 40 if (sqlite3_memdebug_vfs_oom_test && (!x || !sqlite3IsMemJournal(x))) { \ |
| 41 void *pTstAlloc = sqlite3Malloc(10); \ |
| 42 if (!pTstAlloc) return SQLITE_IOERR_NOMEM; \ |
| 43 sqlite3_free(pTstAlloc); \ |
| 44 } |
| 45 #else |
| 46 #define DO_OS_MALLOC_TEST(x) |
| 47 #endif |
| 48 |
| 49 /* |
| 50 ** The following routines are convenience wrappers around methods |
| 51 ** of the sqlite3_file object. This is mostly just syntactic sugar. All |
| 52 ** of this would be completely automatic if SQLite were coded using |
| 53 ** C++ instead of plain old C. |
| 54 */ |
| 55 int sqlite3OsClose(sqlite3_file *pId){ |
| 56 int rc = SQLITE_OK; |
| 57 if( pId->pMethods ){ |
| 58 rc = pId->pMethods->xClose(pId); |
| 59 pId->pMethods = 0; |
| 60 } |
| 61 return rc; |
| 62 } |
| 63 int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){ |
| 64 DO_OS_MALLOC_TEST(id); |
| 65 return id->pMethods->xRead(id, pBuf, amt, offset); |
| 66 } |
| 67 int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){ |
| 68 DO_OS_MALLOC_TEST(id); |
| 69 return id->pMethods->xWrite(id, pBuf, amt, offset); |
| 70 } |
| 71 int sqlite3OsTruncate(sqlite3_file *id, i64 size){ |
| 72 return id->pMethods->xTruncate(id, size); |
| 73 } |
| 74 int sqlite3OsSync(sqlite3_file *id, int flags){ |
| 75 DO_OS_MALLOC_TEST(id); |
| 76 return id->pMethods->xSync(id, flags); |
| 77 } |
| 78 int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){ |
| 79 DO_OS_MALLOC_TEST(id); |
| 80 return id->pMethods->xFileSize(id, pSize); |
| 81 } |
| 82 int sqlite3OsLock(sqlite3_file *id, int lockType){ |
| 83 DO_OS_MALLOC_TEST(id); |
| 84 return id->pMethods->xLock(id, lockType); |
| 85 } |
| 86 int sqlite3OsUnlock(sqlite3_file *id, int lockType){ |
| 87 return id->pMethods->xUnlock(id, lockType); |
| 88 } |
| 89 int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){ |
| 90 DO_OS_MALLOC_TEST(id); |
| 91 return id->pMethods->xCheckReservedLock(id, pResOut); |
| 92 } |
| 93 int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){ |
| 94 return id->pMethods->xFileControl(id, op, pArg); |
| 95 } |
| 96 int sqlite3OsSectorSize(sqlite3_file *id){ |
| 97 int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize; |
| 98 return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE); |
| 99 } |
| 100 int sqlite3OsDeviceCharacteristics(sqlite3_file *id){ |
| 101 return id->pMethods->xDeviceCharacteristics(id); |
| 102 } |
| 103 int sqlite3OsShmLock(sqlite3_file *id, int offset, int n, int flags){ |
| 104 return id->pMethods->xShmLock(id, offset, n, flags); |
| 105 } |
| 106 void sqlite3OsShmBarrier(sqlite3_file *id){ |
| 107 id->pMethods->xShmBarrier(id); |
| 108 } |
| 109 int sqlite3OsShmUnmap(sqlite3_file *id, int deleteFlag){ |
| 110 return id->pMethods->xShmUnmap(id, deleteFlag); |
| 111 } |
| 112 int sqlite3OsShmMap( |
| 113 sqlite3_file *id, /* Database file handle */ |
| 114 int iPage, |
| 115 int pgsz, |
| 116 int bExtend, /* True to extend file if necessary */ |
| 117 void volatile **pp /* OUT: Pointer to mapping */ |
| 118 ){ |
| 119 return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp); |
| 120 } |
| 121 |
| 122 /* |
| 123 ** The next group of routines are convenience wrappers around the |
| 124 ** VFS methods. |
| 125 */ |
| 126 int sqlite3OsOpen( |
| 127 sqlite3_vfs *pVfs, |
| 128 const char *zPath, |
| 129 sqlite3_file *pFile, |
| 130 int flags, |
| 131 int *pFlagsOut |
| 132 ){ |
| 133 int rc; |
| 134 DO_OS_MALLOC_TEST(0); |
| 135 /* 0x87f3f is a mask of SQLITE_OPEN_ flags that are valid to be passed |
| 136 ** down into the VFS layer. Some SQLITE_OPEN_ flags (for example, |
| 137 ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before |
| 138 ** reaching the VFS. */ |
| 139 rc = pVfs->xOpen(pVfs, zPath, pFile, flags & 0x87f3f, pFlagsOut); |
| 140 assert( rc==SQLITE_OK || pFile->pMethods==0 ); |
| 141 return rc; |
| 142 } |
| 143 int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ |
| 144 return pVfs->xDelete(pVfs, zPath, dirSync); |
| 145 } |
| 146 int sqlite3OsAccess( |
| 147 sqlite3_vfs *pVfs, |
| 148 const char *zPath, |
| 149 int flags, |
| 150 int *pResOut |
| 151 ){ |
| 152 DO_OS_MALLOC_TEST(0); |
| 153 return pVfs->xAccess(pVfs, zPath, flags, pResOut); |
| 154 } |
| 155 int sqlite3OsFullPathname( |
| 156 sqlite3_vfs *pVfs, |
| 157 const char *zPath, |
| 158 int nPathOut, |
| 159 char *zPathOut |
| 160 ){ |
| 161 zPathOut[0] = 0; |
| 162 return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut); |
| 163 } |
| 164 #ifndef SQLITE_OMIT_LOAD_EXTENSION |
| 165 void *sqlite3OsDlOpen(sqlite3_vfs *pVfs, const char *zPath){ |
| 166 return pVfs->xDlOpen(pVfs, zPath); |
| 167 } |
| 168 void sqlite3OsDlError(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ |
| 169 pVfs->xDlError(pVfs, nByte, zBufOut); |
| 170 } |
| 171 void (*sqlite3OsDlSym(sqlite3_vfs *pVfs, void *pHdle, const char *zSym))(void){ |
| 172 return pVfs->xDlSym(pVfs, pHdle, zSym); |
| 173 } |
| 174 void sqlite3OsDlClose(sqlite3_vfs *pVfs, void *pHandle){ |
| 175 pVfs->xDlClose(pVfs, pHandle); |
| 176 } |
| 177 #endif /* SQLITE_OMIT_LOAD_EXTENSION */ |
| 178 int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ |
| 179 return pVfs->xRandomness(pVfs, nByte, zBufOut); |
| 180 } |
| 181 int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){ |
| 182 return pVfs->xSleep(pVfs, nMicro); |
| 183 } |
| 184 int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){ |
| 185 int rc; |
| 186 /* IMPLEMENTATION-OF: R-49045-42493 SQLite will use the xCurrentTimeInt64() |
| 187 ** method to get the current date and time if that method is available |
| 188 ** (if iVersion is 2 or greater and the function pointer is not NULL) and |
| 189 ** will fall back to xCurrentTime() if xCurrentTimeInt64() is |
| 190 ** unavailable. |
| 191 */ |
| 192 if( pVfs->iVersion>=2 && pVfs->xCurrentTimeInt64 ){ |
| 193 rc = pVfs->xCurrentTimeInt64(pVfs, pTimeOut); |
| 194 }else{ |
| 195 double r; |
| 196 rc = pVfs->xCurrentTime(pVfs, &r); |
| 197 *pTimeOut = (sqlite3_int64)(r*86400000.0); |
| 198 } |
| 199 return rc; |
| 200 } |
| 201 |
| 202 int sqlite3OsOpenMalloc( |
| 203 sqlite3_vfs *pVfs, |
| 204 const char *zFile, |
| 205 sqlite3_file **ppFile, |
| 206 int flags, |
| 207 int *pOutFlags |
| 208 ){ |
| 209 int rc = SQLITE_NOMEM; |
| 210 sqlite3_file *pFile; |
| 211 pFile = (sqlite3_file *)sqlite3Malloc(pVfs->szOsFile); |
| 212 if( pFile ){ |
| 213 rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags); |
| 214 if( rc!=SQLITE_OK ){ |
| 215 sqlite3_free(pFile); |
| 216 }else{ |
| 217 *ppFile = pFile; |
| 218 } |
| 219 } |
| 220 return rc; |
| 221 } |
| 222 int sqlite3OsCloseFree(sqlite3_file *pFile){ |
| 223 int rc = SQLITE_OK; |
| 224 assert( pFile ); |
| 225 rc = sqlite3OsClose(pFile); |
| 226 sqlite3_free(pFile); |
| 227 return rc; |
| 228 } |
| 229 |
| 230 /* |
| 231 ** This function is a wrapper around the OS specific implementation of |
| 232 ** sqlite3_os_init(). The purpose of the wrapper is to provide the |
| 233 ** ability to simulate a malloc failure, so that the handling of an |
| 234 ** error in sqlite3_os_init() by the upper layers can be tested. |
| 235 */ |
| 236 int sqlite3OsInit(void){ |
| 237 void *p = sqlite3_malloc(10); |
| 238 if( p==0 ) return SQLITE_NOMEM; |
| 239 sqlite3_free(p); |
| 240 return sqlite3_os_init(); |
| 241 } |
| 242 |
| 243 /* |
| 244 ** The list of all registered VFS implementations. |
| 245 */ |
| 246 static sqlite3_vfs * SQLITE_WSD vfsList = 0; |
| 247 #define vfsList GLOBAL(sqlite3_vfs *, vfsList) |
| 248 |
| 249 /* |
| 250 ** Locate a VFS by name. If no name is given, simply return the |
| 251 ** first VFS on the list. |
| 252 */ |
| 253 sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){ |
| 254 sqlite3_vfs *pVfs = 0; |
| 255 #if SQLITE_THREADSAFE |
| 256 sqlite3_mutex *mutex; |
| 257 #endif |
| 258 #ifndef SQLITE_OMIT_AUTOINIT |
| 259 int rc = sqlite3_initialize(); |
| 260 if( rc ) return 0; |
| 261 #endif |
| 262 #if SQLITE_THREADSAFE |
| 263 mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); |
| 264 #endif |
| 265 sqlite3_mutex_enter(mutex); |
| 266 for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){ |
| 267 if( zVfs==0 ) break; |
| 268 if( strcmp(zVfs, pVfs->zName)==0 ) break; |
| 269 } |
| 270 sqlite3_mutex_leave(mutex); |
| 271 return pVfs; |
| 272 } |
| 273 |
| 274 /* |
| 275 ** Unlink a VFS from the linked list |
| 276 */ |
| 277 static void vfsUnlink(sqlite3_vfs *pVfs){ |
| 278 assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) ); |
| 279 if( pVfs==0 ){ |
| 280 /* No-op */ |
| 281 }else if( vfsList==pVfs ){ |
| 282 vfsList = pVfs->pNext; |
| 283 }else if( vfsList ){ |
| 284 sqlite3_vfs *p = vfsList; |
| 285 while( p->pNext && p->pNext!=pVfs ){ |
| 286 p = p->pNext; |
| 287 } |
| 288 if( p->pNext==pVfs ){ |
| 289 p->pNext = pVfs->pNext; |
| 290 } |
| 291 } |
| 292 } |
| 293 |
| 294 /* |
| 295 ** Register a VFS with the system. It is harmless to register the same |
| 296 ** VFS multiple times. The new VFS becomes the default if makeDflt is |
| 297 ** true. |
| 298 */ |
| 299 int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){ |
| 300 sqlite3_mutex *mutex = 0; |
| 301 #ifndef SQLITE_OMIT_AUTOINIT |
| 302 int rc = sqlite3_initialize(); |
| 303 if( rc ) return rc; |
| 304 #endif |
| 305 mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); |
| 306 sqlite3_mutex_enter(mutex); |
| 307 vfsUnlink(pVfs); |
| 308 if( makeDflt || vfsList==0 ){ |
| 309 pVfs->pNext = vfsList; |
| 310 vfsList = pVfs; |
| 311 }else{ |
| 312 pVfs->pNext = vfsList->pNext; |
| 313 vfsList->pNext = pVfs; |
| 314 } |
| 315 assert(vfsList); |
| 316 sqlite3_mutex_leave(mutex); |
| 317 return SQLITE_OK; |
| 318 } |
| 319 |
| 320 /* |
| 321 ** Unregister a VFS so that it is no longer accessible. |
| 322 */ |
| 323 int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){ |
| 324 #if SQLITE_THREADSAFE |
| 325 sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); |
| 326 #endif |
| 327 sqlite3_mutex_enter(mutex); |
| 328 vfsUnlink(pVfs); |
| 329 sqlite3_mutex_leave(mutex); |
| 330 return SQLITE_OK; |
| 331 } |
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