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Overview
Comment: | Initial port of WAL VFS support from os_unix.c to os_win.c. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | wal-win32 |
Files: | files | file ages | folders |
SHA1: |
111ad59f21d53d1ec63c084ca5f98f2a |
User & Date: | shaneh 2010-05-11 02:49:40.000 |
Context
2010-05-12
| ||
17:14 | Updates to WAL support in os_win.c: pulled in latest changes from src/os_unix.c; updated tracing; misc. improvements. (check-in: 76504726a1 user: shaneh tags: wal-win32) | |
2010-05-11
| ||
02:49 | Initial port of WAL VFS support from os_unix.c to os_win.c. (check-in: 111ad59f21 user: shaneh tags: wal-win32) | |
02:46 | Updates to WAL TCL test scripts to support running on Windows. (check-in: 6a5630806c user: shaneh tags: trunk) | |
Changes
Changes to src/os_win.c.
︙ | ︙ | |||
625 626 627 628 629 630 631 | */ #define MX_CLOSE_ATTEMPT 3 static int winClose(sqlite3_file *id){ int rc, cnt = 0; winFile *pFile = (winFile*)id; assert( id!=0 ); | < > | 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 | */ #define MX_CLOSE_ATTEMPT 3 static int winClose(sqlite3_file *id){ int rc, cnt = 0; winFile *pFile = (winFile*)id; assert( id!=0 ); do{ rc = CloseHandle(pFile->h); }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (Sleep(100), 1) ); #if SQLITE_OS_WINCE #define WINCE_DELETION_ATTEMPTS 3 winceDestroyLock(pFile); if( pFile->zDeleteOnClose ){ int cnt = 0; while( DeleteFileW(pFile->zDeleteOnClose)==0 && GetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff && cnt++ < WINCE_DELETION_ATTEMPTS ){ Sleep(100); /* Wait a little before trying again */ } free(pFile->zDeleteOnClose); } #endif OSTRACE(("CLOSE %d %s\n", pFile->h, rc ? "ok" : "failed")); OpenCounter(-1); return rc ? SQLITE_OK : SQLITE_IOERR; } /* ** Some microsoft compilers lack this definition. */ |
︙ | ︙ | |||
742 743 744 745 746 747 748 | /* ** Truncate an open file to a specified size */ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){ LONG upperBits = (LONG)((nByte>>32) & 0x7fffffff); LONG lowerBits = (LONG)(nByte & 0xffffffff); | | > < | | | < | | > | | 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 | /* ** Truncate an open file to a specified size */ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){ LONG upperBits = (LONG)((nByte>>32) & 0x7fffffff); LONG lowerBits = (LONG)(nByte & 0xffffffff); DWORD dwRet; winFile *pFile = (winFile*)id; DWORD error; int rc = SQLITE_OK; assert( id!=0 ); SimulateIOError(return SQLITE_IOERR_TRUNCATE); dwRet = SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN); if( dwRet==INVALID_SET_FILE_POINTER && (error=GetLastError())!=NO_ERROR ){ pFile->lastErrno = error; rc = SQLITE_IOERR_TRUNCATE; /* SetEndOfFile will fail if nByte is negative */ }else if( !SetEndOfFile(pFile->h) ){ pFile->lastErrno = GetLastError(); rc = SQLITE_IOERR_TRUNCATE; } OSTRACE(("TRUNCATE %d %lld %s\n", pFile->h, nByte, rc==SQLITE_OK ? "ok" : "failed")); return rc; } #ifdef SQLITE_TEST /* ** Count the number of fullsyncs and normal syncs. This is used to test ** that syncs and fullsyncs are occuring at the right times. */ |
︙ | ︙ | |||
1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 | winFile *pFile = (winFile*)id; void *zConverted; /* Filename in OS encoding */ const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */ char zTmpname[MAX_PATH+1]; /* Buffer used to create temp filename */ assert( id!=0 ); UNUSED_PARAMETER(pVfs); /* If the second argument to this function is NULL, generate a ** temporary file name to use */ if( !zUtf8Name ){ int rc = getTempname(MAX_PATH+1, zTmpname); if( rc!=SQLITE_OK ){ | > > | 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 | winFile *pFile = (winFile*)id; void *zConverted; /* Filename in OS encoding */ const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */ char zTmpname[MAX_PATH+1]; /* Buffer used to create temp filename */ assert( id!=0 ); UNUSED_PARAMETER(pVfs); pFile->h = INVALID_HANDLE_VALUE; /* If the second argument to this function is NULL, generate a ** temporary file name to use */ if( !zUtf8Name ){ int rc = getTempname(MAX_PATH+1, zTmpname); if( rc!=SQLITE_OK ){ |
︙ | ︙ | |||
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 | NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL ); #endif } if( h==INVALID_HANDLE_VALUE ){ free(zConverted); if( flags & SQLITE_OPEN_READWRITE ){ return winOpen(pVfs, zName, id, ((flags|SQLITE_OPEN_READONLY)&~SQLITE_OPEN_READWRITE), pOutFlags); }else{ return SQLITE_CANTOPEN_BKPT; | > | 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 | NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL ); #endif } OSTRACE4("OPEN %d %s 0x%lx\n", h, zName, dwDesiredAccess); if( h==INVALID_HANDLE_VALUE ){ free(zConverted); if( flags & SQLITE_OPEN_READWRITE ){ return winOpen(pVfs, zName, id, ((flags|SQLITE_OPEN_READONLY)&~SQLITE_OPEN_READWRITE), pOutFlags); }else{ return SQLITE_CANTOPEN_BKPT; |
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1498 1499 1500 1501 1502 1503 1504 | }while( ( ((rc = GetFileAttributesA(zConverted)) != INVALID_FILE_ATTRIBUTES) || ((error = GetLastError()) == ERROR_ACCESS_DENIED)) && (++cnt < MX_DELETION_ATTEMPTS) && (Sleep(100), 1) ); #endif } free(zConverted); | | > | 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 | }while( ( ((rc = GetFileAttributesA(zConverted)) != INVALID_FILE_ATTRIBUTES) || ((error = GetLastError()) == ERROR_ACCESS_DENIED)) && (++cnt < MX_DELETION_ATTEMPTS) && (Sleep(100), 1) ); #endif } free(zConverted); OSTRACE(("DELETE \"%s\" %s\n", zFilename, ( (rc == INVALID_FILE_ATTRIBUTES) && (error == ERROR_FILE_NOT_FOUND)) ? "ok" : "failed" )); return ( (rc == INVALID_FILE_ATTRIBUTES) && (error == ERROR_FILE_NOT_FOUND)) ? SQLITE_OK : SQLITE_IOERR_DELETE; } /* ** Check the existance and status of a file. */ |
︙ | ︙ | |||
1791 1792 1793 1794 1795 1796 1797 | static int winSleep(sqlite3_vfs *pVfs, int microsec){ Sleep((microsec+999)/1000); UNUSED_PARAMETER(pVfs); return ((microsec+999)/1000)*1000; } /* | | > | | | | > > > > | | < < < | < | < | < | < | | > | < | | < < < < | > > > > > > > > > > > > > > > > | 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 | static int winSleep(sqlite3_vfs *pVfs, int microsec){ Sleep((microsec+999)/1000); UNUSED_PARAMETER(pVfs); return ((microsec+999)/1000)*1000; } /* ** The following variable, if set to a non-zero value, is interpreted as ** the number of seconds since 1970 and is used to set the result of ** sqlite3OsCurrentTime() during testing. */ #ifdef SQLITE_TEST int sqlite3_current_time = 0; /* Fake system time in seconds since 1970. */ #endif /* ** Find the current time (in Universal Coordinated Time). Write into *piNow ** the current time and date as a Julian Day number times 86_400_000. In ** other words, write into *piNow the number of milliseconds since the Julian ** epoch of noon in Greenwich on November 24, 4714 B.C according to the ** proleptic Gregorian calendar. ** ** On success, return 0. Return 1 if the time and date cannot be found. */ static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){ /* FILETIME structure is a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601 (= JD 2305813.5). */ FILETIME ft; static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000; #ifdef SQLITE_TEST static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000; #endif /* 2^32 - to avoid use of LL and warnings in gcc */ static const sqlite3_int64 max32BitValue = (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 + (sqlite3_int64)294967296; #if SQLITE_OS_WINCE SYSTEMTIME time; GetSystemTime(&time); /* if SystemTimeToFileTime() fails, it returns zero. */ if (!SystemTimeToFileTime(&time,&ft)){ return 1; } #else GetSystemTimeAsFileTime( &ft ); #endif *piNow = winFiletimeEpoch + ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) + (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)1000; #ifdef SQLITE_TEST if( sqlite3_current_time ){ *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch; } #endif UNUSED_PARAMETER(pVfs); return 0; } /* ** Find the current time (in Universal Coordinated Time). Write the ** current time and date as a Julian Day number into *prNow and ** return 0. Return 1 if the time and date cannot be found. */ int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){ int rc; sqlite3_int64 i; rc = winCurrentTimeInt64(pVfs, &i); if( !rc ){ *prNow = i/86400000.0; } return rc; } /* ** The idea is that this function works like a combination of ** GetLastError() and FormatMessage() on windows (or errno and ** strerror_r() on unix). After an error is returned by an OS ** function, SQLite calls this function with zBuf pointing to ** a buffer of nBuf bytes. The OS layer should populate the |
︙ | ︙ | |||
1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 | ** by sqlite into the error message available to the user using ** sqlite3_errmsg(), possibly making IO errors easier to debug. */ static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){ UNUSED_PARAMETER(pVfs); return getLastErrorMsg(nBuf, zBuf); } /* ** Initialize and deinitialize the operating system interface. */ int sqlite3_os_init(void){ static sqlite3_vfs winVfs = { | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 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2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 | ** by sqlite into the error message available to the user using ** sqlite3_errmsg(), possibly making IO errors easier to debug. */ static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){ UNUSED_PARAMETER(pVfs); return getLastErrorMsg(nBuf, zBuf); } #ifndef SQLITE_OMIT_WAL /* ** Helper functions to obtain and relinquish the global mutex. The ** global mutex is used to protect the winLockInfo objects used by ** this file, all of which may be shared by multiple threads. ** ** Function winShmMutexHeld() is used to assert() that the global mutex ** is held when required. This function is only used as part of assert() ** statements. e.g. ** ** winShmEnterMutex() ** assert( winShmMutexHeld() ); ** winEnterLeave() */ static void winShmEnterMutex(void){ sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)); } static void winShmLeaveMutex(void){ sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)); } #ifdef SQLITE_DEBUG static int winShmMutexHeld(void) { return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)); } #endif /* Forward reference */ typedef struct winShm winShm; typedef struct winShmFile winShmFile; /* ** Object used to represent a single file opened and mmapped to provide ** shared memory. When multiple threads all reference the same ** log-summary, each thread has its own winFile object, but they all ** point to a single instance of this object. In other words, each ** log-summary is opened only once per process. ** ** winShmMutexHeld() must be true when creating or destroying ** this object or while reading or writing the following fields: ** ** nRef ** pNext ** ** The following fields are read-only after the object is created: ** ** fid ** zFilename ** ** Either winShmFile.mutex must be held or winShmFile.nRef==0 and ** winShmMutexHeld() is true when reading or writing any other field ** in this structure. ** ** To avoid deadlocks, mutex and mutexBuf are always released in the ** reverse order that they are acquired. mutexBuf is always acquired ** first and released last. This invariant is check by asserting ** sqlite3_mutex_notheld() on mutex whenever mutexBuf is acquired or ** released. */ struct winShmFile { sqlite3_mutex *mutex; /* Mutex to access this object */ sqlite3_mutex *mutexBuf; /* Mutex to access zBuf[] */ char *zFilename; /* Name of the file */ winFile hFile; /* File handle from winOpen */ HANDLE hMap; /* File handle from CreateFileMapping */ DWORD lastErrno; /* The Windows errno from the last I/O error */ int szMap; /* Size of the mapping of file into memory */ char *pMMapBuf; /* Where currently mmapped(). NULL if unmapped */ int nRef; /* Number of winShm objects pointing to this */ winShm *pFirst; /* All winShm objects pointing to this */ winShmFile *pNext; /* Next in list of all winShmFile objects */ #ifdef SQLITE_DEBUG u8 exclMask; /* Mask of exclusive locks held */ u8 sharedMask; /* Mask of shared locks held */ u8 nextShmId; /* Next available winShm.id value */ #endif }; /* ** A global array of all winShmFile objects. ** ** The winShmMutexHeld() must be true while reading or writing this list. */ static winShmFile *winShmFileList = 0; /* ** Structure used internally by this VFS to record the state of an ** open shared memory connection. ** ** winShm.pFile->mutex must be held while reading or writing the ** winShm.pNext and winShm.locks[] elements. ** ** The winShm.pFile element is initialized when the object is created ** and is read-only thereafter. */ struct winShm { winShmFile *pFile; /* The underlying winShmFile object */ winShm *pNext; /* Next winShm with the same winShmFile */ u8 lockState; /* Current lock state */ u8 hasMutex; /* True if holding the winShmFile mutex */ u8 hasMutexBuf; /* True if holding pFile->mutexBuf */ u8 sharedMask; /* Mask of shared locks held */ u8 exclMask; /* Mask of exclusive locks held */ #ifdef SQLITE_DEBUG u8 id; /* Id of this connection with its winShmFile */ #endif }; /* ** Size increment by which shared memory grows */ #define SQLITE_WIN_SHM_INCR 4096 /* ** Constants used for locking */ #define WIN_SHM_BASE 32 /* Byte offset of the first lock byte */ #define WIN_SHM_DMS 0x01 /* Mask for Dead-Man-Switch lock */ #define WIN_SHM_A 0x10 /* Mask for region locks... */ #define WIN_SHM_B 0x20 #define WIN_SHM_C 0x40 #define WIN_SHM_D 0x80 #ifdef SQLITE_DEBUG /* ** Return a pointer to a nul-terminated string in static memory that ** describes a locking mask. The string is of the form "MSABCD" with ** each character representing a lock. "M" for MUTEX, "S" for DMS, ** and "A" through "D" for the region locks. If a lock is held, the ** letter is shown. If the lock is not held, the letter is converted ** to ".". ** ** This routine is for debugging purposes only and does not appear ** in a production build. */ static const char *winShmLockString(u8 mask){ static char zBuf[48]; static int iBuf = 0; char *z; z = &zBuf[iBuf]; iBuf += 8; if( iBuf>=sizeof(zBuf) ) iBuf = 0; z[0] = (mask & WIN_SHM_DMS) ? 'S' : '.'; z[1] = (mask & WIN_SHM_A) ? 'A' : '.'; z[2] = (mask & WIN_SHM_B) ? 'B' : '.'; z[3] = (mask & WIN_SHM_C) ? 'C' : '.'; z[4] = (mask & WIN_SHM_D) ? 'D' : '.'; z[5] = 0; return z; } #endif /* SQLITE_DEBUG */ /* ** Apply posix advisory locks for all bytes identified in lockMask. ** ** lockMask might contain multiple bits but all bits are guaranteed ** to be contiguous. ** ** Locks block if the mask is exactly WIN_SHM_C and are non-blocking ** otherwise. */ #define _SHM_UNLCK 1 #define _SHM_RDLCK 2 #define _SHM_WRLCK 3 static int winShmSystemLock( winShmFile *pFile, /* Apply locks to this open shared-memory segment */ int lockType, /* _SHM_UNLCK, _SHM_RDLCK, or _SHM_WRLCK */ u8 lockMask /* Which bytes to lock or unlock */ ){ OVERLAPPED ovlp; DWORD dwFlags; int nBytes; /* Number of bytes to lock */ int i; /* Offset into the locking byte range */ int rc = 0; /* Result code form Lock/UnlockFileEx() */ u8 mask; /* Mask of bits in lockMask */ /* Access to the winShmFile object is serialized by the caller */ assert( sqlite3_mutex_held(pFile->mutex) || pFile->nRef==0 ); /* Initialize the locking parameters */ if( lockMask==WIN_SHM_C && lockType!=_SHM_UNLCK ){ dwFlags = 0; OSTRACE(("SHM-LOCK requesting blocking lock %s\n", winShmLockString(lockMask))); }else{ dwFlags = LOCKFILE_FAIL_IMMEDIATELY; OSTRACE(("SHM-LOCK requesting %s %s\n", lockType!=_SHM_UNLCK ? "unlock" : "lock", winShmLockString(lockMask))); } if( lockType == _SHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK; /* Find the first bit in lockMask that is set */ for(i=0, mask=0x01; mask!=0 && (lockMask&mask)==0; mask <<= 1, i++){} assert( mask!=0 ); memset(&ovlp, 0, sizeof(OVERLAPPED)); ovlp.Offset = i+WIN_SHM_BASE; ovlp.OffsetHigh = 0; nBytes = 1; /* Extend the locking range for each additional bit that is set */ mask <<= 1; while( mask!=0 && (lockMask & mask)!=0 ){ nBytes++; mask <<= 1; } /* Verify that all bits set in lockMask are contiguous */ assert( mask==0 || (lockMask & ~(mask | (mask-1)))==0 ); /* Release/Acquire the system-level lock */ if( lockType==_SHM_UNLCK ){ for(i=0; i<nBytes; i++, ovlp.Offset++){ rc = UnlockFileEx(pFile->hFile.h, 0, 1, 0, &ovlp); if( !rc ) break; } if( !rc ){ OSTRACE(("SHM-LOCK UnlockFileEx ERROR %d - 0x%08lx\n", rc, GetLastError())); /* continue to release individual byte locks (if any) */ for(; i<nBytes; i++, ovlp.Offset++){ UnlockFileEx(pFile->hFile.h, 0, 1, 0, &ovlp); } } }else{ /* release old individual byte locks (if any). */ for(i=0; i<nBytes; i++, ovlp.Offset++){ UnlockFileEx(pFile->hFile.h, 0, 1, 0, &ovlp); } ovlp.Offset-=nBytes; /* set new individual byte locks */ for(i=0; i<(int)nBytes; i++, ovlp.Offset++){ rc = LockFileEx(pFile->hFile.h, dwFlags, 0, 1, 0, &ovlp); if( !rc ) break; } if( !rc ){ OSTRACE(("SHM-LOCK LockFileEx ERROR %d - 0x%08lx\n", rc, GetLastError())); /* release individual byte locks (if any) */ ovlp.Offset-=i; for(i=0; i<nBytes; i++, ovlp.Offset++){ UnlockFileEx(pFile->hFile.h, 0, 1, 0, &ovlp); } } } rc = (rc!=0) ? SQLITE_OK : SQLITE_BUSY; /* Update the global lock state and do debug tracing */ #ifdef SQLITE_DEBUG OSTRACE(("SHM-LOCK %d ", pFile->hFile.h)); if( rc==SQLITE_OK ){ if( lockType==_SHM_UNLCK ){ OSTRACE(("unlock ok")); pFile->exclMask &= ~lockMask; pFile->sharedMask &= ~lockMask; }else if( lockType==_SHM_RDLCK ){ OSTRACE(("read-lock ok")); pFile->exclMask &= ~lockMask; pFile->sharedMask |= lockMask; }else{ assert( lockType==_SHM_WRLCK ); OSTRACE(("write-lock ok")); pFile->exclMask |= lockMask; pFile->sharedMask &= ~lockMask; } }else{ if( lockType==_SHM_UNLCK ){ OSTRACE(("unlock failed")); }else if( lockType==_SHM_RDLCK ){ OSTRACE(("read-lock failed")); }else{ assert( lockType==_SHM_WRLCK ); OSTRACE(("write-lock failed")); } } OSTRACE((" - change requested %s - afterwards %s:%s\n", winShmLockString(lockMask), winShmLockString(pFile->sharedMask), winShmLockString(pFile->exclMask))); #endif return rc; } /* ** For connection p, unlock all of the locks identified by the unlockMask ** parameter. */ static int winShmUnlock( winShmFile *pFile, /* The underlying shared-memory file */ winShm *p, /* The connection to be unlocked */ u8 unlockMask /* Mask of locks to be unlocked */ ){ int rc; /* Result code */ winShm *pX; /* For looping over all sibling connections */ u8 allMask; /* Union of locks held by connections other than "p" */ /* Access to the winShmFile object is serialized by the caller */ assert( sqlite3_mutex_held(pFile->mutex) ); /* don't attempt to unlock anything we don't have locks for */ if( (unlockMask & (p->exclMask|p->sharedMask)) != unlockMask ){ OSTRACE(("SHM-UNLOCKING more than we have locked - requested %s - have %s\n", winShmLockString(unlockMask), winShmLockString(p->exclMask|p->sharedMask))); unlockMask &= (p->exclMask|p->sharedMask); } /* Compute locks held by sibling connections */ allMask = 0; for(pX=pFile->pFirst; pX; pX=pX->pNext){ if( pX==p ) continue; assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 ); allMask |= pX->sharedMask; } /* Unlock the system-level locks */ if( (unlockMask & allMask)!=unlockMask ){ rc = winShmSystemLock(pFile, _SHM_UNLCK, unlockMask & ~allMask); }else{ rc = SQLITE_OK; } /* Undo the local locks */ if( rc==SQLITE_OK ){ p->exclMask &= ~unlockMask; p->sharedMask &= ~unlockMask; } return rc; } /* ** Get reader locks for connection p on all locks in the readMask parameter. */ static int winShmSharedLock( winShmFile *pFile, /* The underlying shared-memory file */ winShm *p, /* The connection to get the shared locks */ u8 readMask /* Mask of shared locks to be acquired */ ){ int rc; /* Result code */ winShm *pX; /* For looping over all sibling connections */ u8 allShared; /* Union of locks held by connections other than "p" */ /* Access to the winShmFile object is serialized by the caller */ assert( sqlite3_mutex_held(pFile->mutex) ); /* Find out which shared locks are already held by sibling connections. ** If any sibling already holds an exclusive lock, go ahead and return ** SQLITE_BUSY. */ allShared = 0; for(pX=pFile->pFirst; pX; pX=pX->pNext){ if( pX==p ) continue; if( (pX->exclMask & readMask)!=0 ) return SQLITE_BUSY; allShared |= pX->sharedMask; } /* Get shared locks at the system level, if necessary */ if( (~allShared) & readMask ){ rc = winShmSystemLock(pFile, _SHM_RDLCK, readMask); }else{ rc = SQLITE_OK; } /* Get the local shared locks */ if( rc==SQLITE_OK ){ p->sharedMask |= readMask; } return rc; } /* ** For connection p, get an exclusive lock on all locks identified in ** the writeMask parameter. */ static int winShmExclusiveLock( winShmFile *pFile, /* The underlying shared-memory file */ winShm *p, /* The connection to get the exclusive locks */ u8 writeMask /* Mask of exclusive locks to be acquired */ ){ int rc; /* Result code */ winShm *pX; /* For looping over all sibling connections */ /* Access to the winShmFile object is serialized by the caller */ assert( sqlite3_mutex_held(pFile->mutex) ); /* Make sure no sibling connections hold locks that will block this ** lock. If any do, return SQLITE_BUSY right away. */ for(pX=pFile->pFirst; pX; pX=pX->pNext){ if( pX==p ) continue; if( (pX->exclMask & writeMask)!=0 ) return SQLITE_BUSY; if( (pX->sharedMask & writeMask)!=0 ) return SQLITE_BUSY; } /* Get the exclusive locks at the system level. Then if successful ** also mark the local connection as being locked. */ rc = winShmSystemLock(pFile, _SHM_WRLCK, writeMask); if( rc==SQLITE_OK ){ p->sharedMask &= ~writeMask; p->exclMask |= writeMask; } return rc; } /* ** Purge the winShmFileList list of all entries with winShmFile.nRef==0. ** ** This is not a VFS shared-memory method; it is a utility function called ** by VFS shared-memory methods. */ static void winShmPurge(void){ winShmFile **pp; winShmFile *p; assert( winShmMutexHeld() ); pp = &winShmFileList; while( (p = *pp)!=0 ){ if( p->nRef==0 ){ if( p->mutex ) sqlite3_mutex_free(p->mutex); if( p->mutexBuf ) sqlite3_mutex_free(p->mutexBuf); if( p->pMMapBuf ){ UnmapViewOfFile(p->pMMapBuf); } if( INVALID_HANDLE_VALUE != p->hMap ){ CloseHandle(p->hMap); } if( p->hFile.h != INVALID_HANDLE_VALUE ) { winClose((sqlite3_file *)&p->hFile); } *pp = p->pNext; sqlite3_free(p); }else{ pp = &p->pNext; } } } /* ** Open a shared-memory area. This particular implementation uses ** mmapped files. ** ** zName is a filename used to identify the shared-memory area. The ** implementation does not (and perhaps should not) use this name ** directly, but rather use it as a template for finding an appropriate ** name for the shared-memory storage. In this implementation, the ** string "-index" is appended to zName and used as the name of the ** mmapped file. ** ** When opening a new shared-memory file, if no other instances of that ** file are currently open, in this process or in other processes, then ** the file must be truncated to zero length or have its header cleared. */ static int winShmOpen( sqlite3_vfs *pVfs, /* The VFS */ const char *zName, /* Name of the corresponding database file */ sqlite3_shm **pShm /* Write the winShm object created here */ ){ struct winShm *p = 0; /* The connection to be opened */ struct winShmFile *pFile = 0; /* The underlying mmapped file */ int rc; /* Result code */ struct winShmFile *pNew; /* Newly allocated pFile */ int nName; /* Size of zName in bytes */ /* Allocate space for the new sqlite3_shm object. Also speculatively ** allocate space for a new winShmFile and filename. */ p = sqlite3_malloc( sizeof(*p) ); if( p==0 ) return SQLITE_NOMEM; memset(p, 0, sizeof(*p)); nName = strlen(zName); pNew = sqlite3_malloc( sizeof(*pFile) + nName + 15 ); if( pNew==0 ){ sqlite3_free(p); return SQLITE_NOMEM; } memset(pNew, 0, sizeof(*pNew)); pNew->zFilename = (char*)&pNew[1]; sqlite3_snprintf(nName+11, pNew->zFilename, "%s-wal-index", zName); /* Look to see if there is an existing winShmFile that can be used. ** If no matching winShmFile currently exists, create a new one. */ winShmEnterMutex(); for(pFile = winShmFileList; pFile; pFile=pFile->pNext){ /* TBD need to come up with better match here. Perhaps ** use winFullPathname() or FILE_ID_BOTH_DIR_INFO Structure. */ if( strcmp(pFile->zFilename, pNew->zFilename)==0 ) break; } if( pFile ){ sqlite3_free(pNew); }else{ pFile = pNew; pNew = 0; pFile->pMMapBuf = NULL; pFile->hMap = INVALID_HANDLE_VALUE; ((winFile*)(&pFile->hFile))->h = INVALID_HANDLE_VALUE; pFile->pNext = winShmFileList; winShmFileList = pFile; pFile->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST); if( pFile->mutex==0 ){ rc = SQLITE_NOMEM; goto shm_open_err; } pFile->mutexBuf = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST); if( pFile->mutexBuf==0 ){ rc = SQLITE_NOMEM; goto shm_open_err; } rc = winOpen(pVfs, pFile->zFilename, /* Name of the file (UTF-8) */ (sqlite3_file *)&pFile->hFile, /* Write the SQLite file handle here */ SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, /* Open mode flags */ 0); if( SQLITE_OK!=rc ){ rc = SQLITE_CANTOPEN_BKPT; goto shm_open_err; } /* Check to see if another process is holding the dead-man switch. ** If not, truncate the file to zero length. */ if( winShmSystemLock(pFile, _SHM_WRLCK, WIN_SHM_DMS)==SQLITE_OK ){ rc = winTruncate((sqlite3_file *)&pFile->hFile, 0); } if( rc==SQLITE_OK ){ rc = winShmSystemLock(pFile, _SHM_RDLCK, WIN_SHM_DMS); } if( rc ) goto shm_open_err; } /* Make the new connection a child of the winShmFile */ p->pFile = pFile; p->pNext = pFile->pFirst; #ifdef SQLITE_DEBUG p->id = pFile->nextShmId++; #endif pFile->pFirst = p; pFile->nRef++; *pShm = (sqlite3_shm*)p; winShmLeaveMutex(); return SQLITE_OK; /* Jump here on any error */ shm_open_err: winShmSystemLock(pFile, _SHM_UNLCK, WIN_SHM_DMS); winShmPurge(); /* This call frees pFile if required */ sqlite3_free(p); sqlite3_free(pNew); *pShm = 0; winShmLeaveMutex(); return rc; } /* ** Close a connection to shared-memory. Delete the underlying ** storage if deleteFlag is true. */ static int winShmClose( sqlite3_vfs *pVfs, /* The VFS */ sqlite3_shm *pSharedMem, /* The shared-memory to be closed */ int deleteFlag /* Delete after closing if true */ ){ winShm *p; /* The connection to be closed */ winShmFile *pFile; /* The underlying shared-memory file */ winShm **pp; /* For looping over sibling connections */ UNUSED_PARAMETER(pVfs); if( pSharedMem==0 ) return SQLITE_OK; p = (struct winShm*)pSharedMem; pFile = p->pFile; /* Verify that the connection being closed holds no locks */ assert( p->exclMask==0 ); assert( p->sharedMask==0 ); /* Remove connection p from the set of connections associated with pFile */ sqlite3_mutex_enter(pFile->mutex); for(pp=&pFile->pFirst; (*pp)!=p; pp = &(*pp)->pNext){} *pp = p->pNext; /* Free the connection p */ sqlite3_free(p); sqlite3_mutex_leave(pFile->mutex); /* If pFile->nRef has reached 0, then close the underlying ** shared-memory file, too */ winShmEnterMutex(); assert( pFile->nRef>0 ); pFile->nRef--; if( pFile->nRef==0 ){ if( deleteFlag ) winDelete(pVfs, pFile->zFilename, 0); winShmPurge(); } winShmLeaveMutex(); return SQLITE_OK; } /* ** Query and/or changes the size of the underlying storage for ** a shared-memory segment. The reqSize parameter is the new size ** of the underlying storage, or -1 to do just a query. The size ** of the underlying storage (after resizing if resizing occurs) is ** written into pNewSize. ** ** This routine does not (necessarily) change the size of the mapping ** of the underlying storage into memory. Use xShmGet() to change ** the mapping size. ** ** The reqSize parameter is the minimum size requested. The implementation ** is free to expand the storage to some larger amount if it chooses. */ static int winShmSize( sqlite3_vfs *pVfs, /* The VFS */ sqlite3_shm *pSharedMem, /* Pointer returned by winShmOpen() */ int reqSize, /* Requested size. -1 for query only */ int *pNewSize /* Write new size here */ ){ winShm *p = (winShm*)pSharedMem; winShmFile *pFile = p->pFile; int rc = SQLITE_OK; UNUSED_PARAMETER(pVfs); if( reqSize>=0 ){ reqSize = (reqSize + SQLITE_WIN_SHM_INCR - 1)/SQLITE_WIN_SHM_INCR; reqSize *= SQLITE_WIN_SHM_INCR; rc = winTruncate((sqlite3_file *)&pFile->hFile, reqSize); } if( SQLITE_OK==rc ){ sqlite3_int64 sz; rc = winFileSize((sqlite3_file *)&pFile->hFile, &sz); if( SQLITE_OK==rc ){ *pNewSize = (int)sz; }else{ *pNewSize = 0; rc = SQLITE_IOERR; } } return rc; } /* ** Map the shared storage into memory. The minimum size of the ** mapping should be reqMapSize if reqMapSize is positive. If ** reqMapSize is zero or negative, the implementation can choose ** whatever mapping size is convenient. ** ** *ppBuf is made to point to the memory which is a mapping of the ** underlying storage. A mutex is acquired to prevent other threads ** from running while *ppBuf is in use in order to prevent other threads ** remapping *ppBuf out from under this thread. The winShmRelease() ** call will release the mutex. However, if the lock state is CHECKPOINT, ** the mutex is not acquired because CHECKPOINT will never remap the ** buffer. RECOVER might remap, though, so CHECKPOINT will acquire ** the mutex if and when it promotes to RECOVER. ** ** RECOVER needs to be atomic. The same mutex that prevents *ppBuf from ** being remapped also prevents more than one thread from being in ** RECOVER at a time. But, RECOVER sometimes wants to remap itself. ** To prevent RECOVER from losing its lock while remapping, the ** mutex is not released by winShmRelease() when in RECOVER. ** ** *pNewMapSize is set to the size of the mapping. ** ** *ppBuf and *pNewMapSize might be NULL and zero if no space has ** yet been allocated to the underlying storage. */ static int winShmGet( sqlite3_vfs *pVfs, /* The VFS */ sqlite3_shm *pSharedMem, /* Pointer returned by winShmOpen() */ int reqMapSize, /* Requested size of mapping. -1 means don't care */ int *pNewMapSize, /* Write new size of mapping here */ void **ppBuf /* Write mapping buffer origin here */ ){ winShm *p = (winShm*)pSharedMem; winShmFile *pFile = p->pFile; int rc = SQLITE_OK; if( p->lockState!=SQLITE_SHM_CHECKPOINT && p->hasMutexBuf==0 ){ assert( sqlite3_mutex_notheld(pFile->mutex) ); sqlite3_mutex_enter(pFile->mutexBuf); p->hasMutexBuf = 1; } sqlite3_mutex_enter(pFile->mutex); if( pFile->szMap==0 || reqMapSize>pFile->szMap ){ int actualSize; if( winShmSize(pVfs, pSharedMem, -1, &actualSize)==SQLITE_OK && reqMapSize<actualSize ){ reqMapSize = actualSize; } if( pFile->pMMapBuf ){ if( !UnmapViewOfFile(pFile->pMMapBuf) ){ pFile->lastErrno = GetLastError(); rc = SQLITE_IOERR; } CloseHandle(pFile->hMap); pFile->hMap = INVALID_HANDLE_VALUE; } if( SQLITE_OK == rc ){ pFile->pMMapBuf = 0; if( reqMapSize == 0 ){ /* can't create 0 byte file mapping in Windows */ pFile->szMap = 0; }else{ /* create the file mapping object */ if( INVALID_HANDLE_VALUE == pFile->hMap ){ /* TBD provide an object name to each file ** mapping so it can be re-used across processes. */ pFile->hMap = CreateFileMapping(pFile->hFile.h, NULL, PAGE_READWRITE, 0, reqMapSize, NULL); } if( NULL==pFile->hMap ){ pFile->lastErrno = GetLastError(); rc = SQLITE_IOERR; pFile->szMap = 0; pFile->hMap = INVALID_HANDLE_VALUE; }else{ pFile->pMMapBuf = MapViewOfFile(pFile->hMap, FILE_MAP_WRITE | FILE_MAP_READ, 0, 0, reqMapSize); if( !pFile->pMMapBuf ){ pFile->lastErrno = GetLastError(); rc = SQLITE_IOERR; pFile->szMap = 0; }else{ pFile->szMap = reqMapSize; } } } } } *pNewMapSize = pFile->szMap; *ppBuf = pFile->pMMapBuf; sqlite3_mutex_leave(pFile->mutex); return rc; } /* ** Release the lock held on the shared memory segment so that other ** threads are free to resize it if necessary. ** ** If the lock is not currently held, this routine is a harmless no-op. ** ** If the shared-memory object is in lock state RECOVER, then we do not ** really want to release the lock, so in that case too, this routine ** is a no-op. */ static int winShmRelease(sqlite3_vfs *pVfs, sqlite3_shm *pSharedMem){ winShm *p = (winShm*)pSharedMem; UNUSED_PARAMETER(pVfs); if( p->hasMutexBuf && p->lockState!=SQLITE_SHM_RECOVER ){ winShmFile *pFile = p->pFile; assert( sqlite3_mutex_notheld(pFile->mutex) ); sqlite3_mutex_leave(pFile->mutexBuf); p->hasMutexBuf = 0; } return SQLITE_OK; } /* ** Symbolic names for LOCK states used for debugging. */ #ifdef SQLITE_DEBUG static const char *azLkName[] = { "UNLOCK", "READ", "READ_FULL", "WRITE", "PENDING", "CHECKPOINT", "RECOVER" }; #endif /* ** Change the lock state for a shared-memory segment. */ static int winShmLock( sqlite3_vfs *pVfs, /* The VFS */ sqlite3_shm *pSharedMem, /* Pointer from winShmOpen() */ int desiredLock, /* One of SQLITE_SHM_xxxxx locking states */ int *pGotLock /* The lock you actually got */ ){ winShm *p = (winShm*)pSharedMem; winShmFile *pFile = p->pFile; int rc = SQLITE_PROTOCOL; UNUSED_PARAMETER(pVfs); /* Note that SQLITE_SHM_READ_FULL and SQLITE_SHM_PENDING are never ** directly requested; they are side effects from requesting ** SQLITE_SHM_READ and SQLITE_SHM_CHECKPOINT, respectively. */ assert( desiredLock==SQLITE_SHM_UNLOCK || desiredLock==SQLITE_SHM_READ || desiredLock==SQLITE_SHM_WRITE || desiredLock==SQLITE_SHM_CHECKPOINT || desiredLock==SQLITE_SHM_RECOVER ); /* Return directly if this is just a lock state query, or if ** the connection is already in the desired locking state. */ if( desiredLock==p->lockState || (desiredLock==SQLITE_SHM_READ && p->lockState==SQLITE_SHM_READ_FULL) ){ OSTRACE(("SHM-LOCK shmid-%d, pid-%d request %s and got %s\n", p->id, (int)GetCurrentProcessId(), azLkName[desiredLock], azLkName[p->lockState])); if( pGotLock ) *pGotLock = p->lockState; return SQLITE_OK; } OSTRACE(("SHM-LOCK shmid-%d, pid-%d request %s->%s\n", p->id, (int)GetCurrentProcessId(), azLkName[p->lockState], azLkName[desiredLock])); if( desiredLock==SQLITE_SHM_RECOVER && !p->hasMutexBuf ){ assert( sqlite3_mutex_notheld(pFile->mutex) ); sqlite3_mutex_enter(pFile->mutexBuf); p->hasMutexBuf = 1; } sqlite3_mutex_enter(pFile->mutex); switch( desiredLock ){ case SQLITE_SHM_UNLOCK: { assert( p->lockState!=SQLITE_SHM_RECOVER ); winShmUnlock(pFile, p, WIN_SHM_A|WIN_SHM_B|WIN_SHM_C|WIN_SHM_D); rc = SQLITE_OK; p->lockState = SQLITE_SHM_UNLOCK; break; } case SQLITE_SHM_READ: { if( p->lockState==SQLITE_SHM_UNLOCK ){ int nAttempt; rc = SQLITE_BUSY; assert( p->lockState==SQLITE_SHM_UNLOCK ); for(nAttempt=0; nAttempt<5 && rc==SQLITE_BUSY; nAttempt++){ rc = winShmSharedLock(pFile, p, WIN_SHM_A|WIN_SHM_B); if( rc==SQLITE_BUSY ){ rc = winShmSharedLock(pFile, p, WIN_SHM_D); if( rc==SQLITE_OK ){ p->lockState = SQLITE_SHM_READ_FULL; } }else{ winShmUnlock(pFile, p, WIN_SHM_B); p->lockState = SQLITE_SHM_READ; } } }else{ assert( p->lockState==SQLITE_SHM_WRITE || p->lockState==SQLITE_SHM_RECOVER ); rc = winShmSharedLock(pFile, p, WIN_SHM_A); winShmUnlock(pFile, p, WIN_SHM_C|WIN_SHM_D); p->lockState = SQLITE_SHM_READ; } break; } case SQLITE_SHM_WRITE: { assert( p->lockState==SQLITE_SHM_READ || p->lockState==SQLITE_SHM_READ_FULL ); rc = winShmExclusiveLock(pFile, p, WIN_SHM_C|WIN_SHM_D); if( rc==SQLITE_OK ){ p->lockState = SQLITE_SHM_WRITE; } break; } case SQLITE_SHM_CHECKPOINT: { assert( p->lockState==SQLITE_SHM_UNLOCK || p->lockState==SQLITE_SHM_PENDING ); if( p->lockState==SQLITE_SHM_UNLOCK ){ rc = winShmExclusiveLock(pFile, p, WIN_SHM_B|WIN_SHM_C); if( rc==SQLITE_OK ){ p->lockState = SQLITE_SHM_PENDING; } } if( p->lockState==SQLITE_SHM_PENDING ){ rc = winShmExclusiveLock(pFile, p, WIN_SHM_A); if( rc==SQLITE_OK ){ p->lockState = SQLITE_SHM_CHECKPOINT; } } break; } default: { assert( desiredLock==SQLITE_SHM_RECOVER ); assert( p->lockState==SQLITE_SHM_READ || p->lockState==SQLITE_SHM_READ_FULL ); assert( sqlite3_mutex_held(pFile->mutexBuf) ); rc = winShmExclusiveLock(pFile, p, WIN_SHM_C); if( rc==SQLITE_OK ){ p->lockState = SQLITE_SHM_RECOVER; } break; } } sqlite3_mutex_leave(pFile->mutex); OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %s\n", p->id, (int)GetCurrentProcessId(), azLkName[p->lockState])); if( pGotLock ) *pGotLock = p->lockState; return rc; } #else # define winShmOpen 0 # define winShmSize 0 # define winShmGet 0 # define winShmRelease 0 # define winShmLock 0 # define winShmClose 0 #endif /* #ifndef SQLITE_OMIT_WAL */ /* ** Initialize and deinitialize the operating system interface. */ int sqlite3_os_init(void){ static sqlite3_vfs winVfs = { 2, /* iVersion */ sizeof(winFile), /* szOsFile */ MAX_PATH, /* mxPathname */ 0, /* pNext */ "win32", /* zName */ 0, /* pAppData */ winOpen, /* xOpen */ winDelete, /* xDelete */ winAccess, /* xAccess */ winFullPathname, /* xFullPathname */ winDlOpen, /* xDlOpen */ winDlError, /* xDlError */ winDlSym, /* xDlSym */ winDlClose, /* xDlClose */ winRandomness, /* xRandomness */ winSleep, /* xSleep */ winCurrentTime, /* xCurrentTime */ winGetLastError, /* xGetLastError */ winShmOpen, /* xShmOpen */ winShmSize, /* xShmSize */ winShmGet, /* xShmGet */ winShmRelease, /* xShmRelease */ winShmLock, /* xShmLock */ winShmClose, /* xShmClose */ 0, /* xRename */ winCurrentTimeInt64, /* xCurrentTimeInt64 */ }; sqlite3_vfs_register(&winVfs, 1); return SQLITE_OK; } int sqlite3_os_end(void){ return SQLITE_OK; } #endif /* SQLITE_OS_WIN */ |