Annotation of embedaddon/sqlite3/src/os.c, revision 1.1
1.1 ! misho 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: ** sqlite3OsRead()
! 31: ** sqlite3OsWrite()
! 32: ** sqlite3OsSync()
! 33: ** sqlite3OsFileSize()
! 34: ** sqlite3OsLock()
! 35: ** sqlite3OsCheckReservedLock()
! 36: ** sqlite3OsFileControl()
! 37: ** sqlite3OsShmMap()
! 38: ** sqlite3OsOpen()
! 39: ** sqlite3OsDelete()
! 40: ** sqlite3OsAccess()
! 41: ** sqlite3OsFullPathname()
! 42: **
! 43: */
! 44: #if defined(SQLITE_TEST)
! 45: int sqlite3_memdebug_vfs_oom_test = 1;
! 46: #define DO_OS_MALLOC_TEST(x) \
! 47: if (sqlite3_memdebug_vfs_oom_test && (!x || !sqlite3IsMemJournal(x))) { \
! 48: void *pTstAlloc = sqlite3Malloc(10); \
! 49: if (!pTstAlloc) return SQLITE_IOERR_NOMEM; \
! 50: sqlite3_free(pTstAlloc); \
! 51: }
! 52: #else
! 53: #define DO_OS_MALLOC_TEST(x)
! 54: #endif
! 55:
! 56: /*
! 57: ** The following routines are convenience wrappers around methods
! 58: ** of the sqlite3_file object. This is mostly just syntactic sugar. All
! 59: ** of this would be completely automatic if SQLite were coded using
! 60: ** C++ instead of plain old C.
! 61: */
! 62: int sqlite3OsClose(sqlite3_file *pId){
! 63: int rc = SQLITE_OK;
! 64: if( pId->pMethods ){
! 65: rc = pId->pMethods->xClose(pId);
! 66: pId->pMethods = 0;
! 67: }
! 68: return rc;
! 69: }
! 70: int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
! 71: DO_OS_MALLOC_TEST(id);
! 72: return id->pMethods->xRead(id, pBuf, amt, offset);
! 73: }
! 74: int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){
! 75: DO_OS_MALLOC_TEST(id);
! 76: return id->pMethods->xWrite(id, pBuf, amt, offset);
! 77: }
! 78: int sqlite3OsTruncate(sqlite3_file *id, i64 size){
! 79: return id->pMethods->xTruncate(id, size);
! 80: }
! 81: int sqlite3OsSync(sqlite3_file *id, int flags){
! 82: DO_OS_MALLOC_TEST(id);
! 83: return id->pMethods->xSync(id, flags);
! 84: }
! 85: int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){
! 86: DO_OS_MALLOC_TEST(id);
! 87: return id->pMethods->xFileSize(id, pSize);
! 88: }
! 89: int sqlite3OsLock(sqlite3_file *id, int lockType){
! 90: DO_OS_MALLOC_TEST(id);
! 91: return id->pMethods->xLock(id, lockType);
! 92: }
! 93: int sqlite3OsUnlock(sqlite3_file *id, int lockType){
! 94: return id->pMethods->xUnlock(id, lockType);
! 95: }
! 96: int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){
! 97: DO_OS_MALLOC_TEST(id);
! 98: return id->pMethods->xCheckReservedLock(id, pResOut);
! 99: }
! 100:
! 101: /*
! 102: ** Use sqlite3OsFileControl() when we are doing something that might fail
! 103: ** and we need to know about the failures. Use sqlite3OsFileControlHint()
! 104: ** when simply tossing information over the wall to the VFS and we do not
! 105: ** really care if the VFS receives and understands the information since it
! 106: ** is only a hint and can be safely ignored. The sqlite3OsFileControlHint()
! 107: ** routine has no return value since the return value would be meaningless.
! 108: */
! 109: int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
! 110: DO_OS_MALLOC_TEST(id);
! 111: return id->pMethods->xFileControl(id, op, pArg);
! 112: }
! 113: void sqlite3OsFileControlHint(sqlite3_file *id, int op, void *pArg){
! 114: (void)id->pMethods->xFileControl(id, op, pArg);
! 115: }
! 116:
! 117: int sqlite3OsSectorSize(sqlite3_file *id){
! 118: int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize;
! 119: return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE);
! 120: }
! 121: int sqlite3OsDeviceCharacteristics(sqlite3_file *id){
! 122: return id->pMethods->xDeviceCharacteristics(id);
! 123: }
! 124: int sqlite3OsShmLock(sqlite3_file *id, int offset, int n, int flags){
! 125: return id->pMethods->xShmLock(id, offset, n, flags);
! 126: }
! 127: void sqlite3OsShmBarrier(sqlite3_file *id){
! 128: id->pMethods->xShmBarrier(id);
! 129: }
! 130: int sqlite3OsShmUnmap(sqlite3_file *id, int deleteFlag){
! 131: return id->pMethods->xShmUnmap(id, deleteFlag);
! 132: }
! 133: int sqlite3OsShmMap(
! 134: sqlite3_file *id, /* Database file handle */
! 135: int iPage,
! 136: int pgsz,
! 137: int bExtend, /* True to extend file if necessary */
! 138: void volatile **pp /* OUT: Pointer to mapping */
! 139: ){
! 140: DO_OS_MALLOC_TEST(id);
! 141: return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);
! 142: }
! 143:
! 144: /*
! 145: ** The next group of routines are convenience wrappers around the
! 146: ** VFS methods.
! 147: */
! 148: int sqlite3OsOpen(
! 149: sqlite3_vfs *pVfs,
! 150: const char *zPath,
! 151: sqlite3_file *pFile,
! 152: int flags,
! 153: int *pFlagsOut
! 154: ){
! 155: int rc;
! 156: DO_OS_MALLOC_TEST(0);
! 157: /* 0x87f7f is a mask of SQLITE_OPEN_ flags that are valid to be passed
! 158: ** down into the VFS layer. Some SQLITE_OPEN_ flags (for example,
! 159: ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
! 160: ** reaching the VFS. */
! 161: rc = pVfs->xOpen(pVfs, zPath, pFile, flags & 0x87f7f, pFlagsOut);
! 162: assert( rc==SQLITE_OK || pFile->pMethods==0 );
! 163: return rc;
! 164: }
! 165: int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
! 166: DO_OS_MALLOC_TEST(0);
! 167: assert( dirSync==0 || dirSync==1 );
! 168: return pVfs->xDelete(pVfs, zPath, dirSync);
! 169: }
! 170: int sqlite3OsAccess(
! 171: sqlite3_vfs *pVfs,
! 172: const char *zPath,
! 173: int flags,
! 174: int *pResOut
! 175: ){
! 176: DO_OS_MALLOC_TEST(0);
! 177: return pVfs->xAccess(pVfs, zPath, flags, pResOut);
! 178: }
! 179: int sqlite3OsFullPathname(
! 180: sqlite3_vfs *pVfs,
! 181: const char *zPath,
! 182: int nPathOut,
! 183: char *zPathOut
! 184: ){
! 185: DO_OS_MALLOC_TEST(0);
! 186: zPathOut[0] = 0;
! 187: return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
! 188: }
! 189: #ifndef SQLITE_OMIT_LOAD_EXTENSION
! 190: void *sqlite3OsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
! 191: return pVfs->xDlOpen(pVfs, zPath);
! 192: }
! 193: void sqlite3OsDlError(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
! 194: pVfs->xDlError(pVfs, nByte, zBufOut);
! 195: }
! 196: void (*sqlite3OsDlSym(sqlite3_vfs *pVfs, void *pHdle, const char *zSym))(void){
! 197: return pVfs->xDlSym(pVfs, pHdle, zSym);
! 198: }
! 199: void sqlite3OsDlClose(sqlite3_vfs *pVfs, void *pHandle){
! 200: pVfs->xDlClose(pVfs, pHandle);
! 201: }
! 202: #endif /* SQLITE_OMIT_LOAD_EXTENSION */
! 203: int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
! 204: return pVfs->xRandomness(pVfs, nByte, zBufOut);
! 205: }
! 206: int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){
! 207: return pVfs->xSleep(pVfs, nMicro);
! 208: }
! 209: int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
! 210: int rc;
! 211: /* IMPLEMENTATION-OF: R-49045-42493 SQLite will use the xCurrentTimeInt64()
! 212: ** method to get the current date and time if that method is available
! 213: ** (if iVersion is 2 or greater and the function pointer is not NULL) and
! 214: ** will fall back to xCurrentTime() if xCurrentTimeInt64() is
! 215: ** unavailable.
! 216: */
! 217: if( pVfs->iVersion>=2 && pVfs->xCurrentTimeInt64 ){
! 218: rc = pVfs->xCurrentTimeInt64(pVfs, pTimeOut);
! 219: }else{
! 220: double r;
! 221: rc = pVfs->xCurrentTime(pVfs, &r);
! 222: *pTimeOut = (sqlite3_int64)(r*86400000.0);
! 223: }
! 224: return rc;
! 225: }
! 226:
! 227: int sqlite3OsOpenMalloc(
! 228: sqlite3_vfs *pVfs,
! 229: const char *zFile,
! 230: sqlite3_file **ppFile,
! 231: int flags,
! 232: int *pOutFlags
! 233: ){
! 234: int rc = SQLITE_NOMEM;
! 235: sqlite3_file *pFile;
! 236: pFile = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile);
! 237: if( pFile ){
! 238: rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags);
! 239: if( rc!=SQLITE_OK ){
! 240: sqlite3_free(pFile);
! 241: }else{
! 242: *ppFile = pFile;
! 243: }
! 244: }
! 245: return rc;
! 246: }
! 247: int sqlite3OsCloseFree(sqlite3_file *pFile){
! 248: int rc = SQLITE_OK;
! 249: assert( pFile );
! 250: rc = sqlite3OsClose(pFile);
! 251: sqlite3_free(pFile);
! 252: return rc;
! 253: }
! 254:
! 255: /*
! 256: ** This function is a wrapper around the OS specific implementation of
! 257: ** sqlite3_os_init(). The purpose of the wrapper is to provide the
! 258: ** ability to simulate a malloc failure, so that the handling of an
! 259: ** error in sqlite3_os_init() by the upper layers can be tested.
! 260: */
! 261: int sqlite3OsInit(void){
! 262: void *p = sqlite3_malloc(10);
! 263: if( p==0 ) return SQLITE_NOMEM;
! 264: sqlite3_free(p);
! 265: return sqlite3_os_init();
! 266: }
! 267:
! 268: /*
! 269: ** The list of all registered VFS implementations.
! 270: */
! 271: static sqlite3_vfs * SQLITE_WSD vfsList = 0;
! 272: #define vfsList GLOBAL(sqlite3_vfs *, vfsList)
! 273:
! 274: /*
! 275: ** Locate a VFS by name. If no name is given, simply return the
! 276: ** first VFS on the list.
! 277: */
! 278: sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
! 279: sqlite3_vfs *pVfs = 0;
! 280: #if SQLITE_THREADSAFE
! 281: sqlite3_mutex *mutex;
! 282: #endif
! 283: #ifndef SQLITE_OMIT_AUTOINIT
! 284: int rc = sqlite3_initialize();
! 285: if( rc ) return 0;
! 286: #endif
! 287: #if SQLITE_THREADSAFE
! 288: mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
! 289: #endif
! 290: sqlite3_mutex_enter(mutex);
! 291: for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){
! 292: if( zVfs==0 ) break;
! 293: if( strcmp(zVfs, pVfs->zName)==0 ) break;
! 294: }
! 295: sqlite3_mutex_leave(mutex);
! 296: return pVfs;
! 297: }
! 298:
! 299: /*
! 300: ** Unlink a VFS from the linked list
! 301: */
! 302: static void vfsUnlink(sqlite3_vfs *pVfs){
! 303: assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) );
! 304: if( pVfs==0 ){
! 305: /* No-op */
! 306: }else if( vfsList==pVfs ){
! 307: vfsList = pVfs->pNext;
! 308: }else if( vfsList ){
! 309: sqlite3_vfs *p = vfsList;
! 310: while( p->pNext && p->pNext!=pVfs ){
! 311: p = p->pNext;
! 312: }
! 313: if( p->pNext==pVfs ){
! 314: p->pNext = pVfs->pNext;
! 315: }
! 316: }
! 317: }
! 318:
! 319: /*
! 320: ** Register a VFS with the system. It is harmless to register the same
! 321: ** VFS multiple times. The new VFS becomes the default if makeDflt is
! 322: ** true.
! 323: */
! 324: int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
! 325: MUTEX_LOGIC(sqlite3_mutex *mutex;)
! 326: #ifndef SQLITE_OMIT_AUTOINIT
! 327: int rc = sqlite3_initialize();
! 328: if( rc ) return rc;
! 329: #endif
! 330: MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
! 331: sqlite3_mutex_enter(mutex);
! 332: vfsUnlink(pVfs);
! 333: if( makeDflt || vfsList==0 ){
! 334: pVfs->pNext = vfsList;
! 335: vfsList = pVfs;
! 336: }else{
! 337: pVfs->pNext = vfsList->pNext;
! 338: vfsList->pNext = pVfs;
! 339: }
! 340: assert(vfsList);
! 341: sqlite3_mutex_leave(mutex);
! 342: return SQLITE_OK;
! 343: }
! 344:
! 345: /*
! 346: ** Unregister a VFS so that it is no longer accessible.
! 347: */
! 348: int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
! 349: #if SQLITE_THREADSAFE
! 350: sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
! 351: #endif
! 352: sqlite3_mutex_enter(mutex);
! 353: vfsUnlink(pVfs);
! 354: sqlite3_mutex_leave(mutex);
! 355: return SQLITE_OK;
! 356: }
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