diff options
Diffstat (limited to 'src/wal.c')
| -rw-r--r-- | src/wal.c | 44 |
1 files changed, 44 insertions, 0 deletions
@@ -784,8 +784,35 @@ int sqlite3WalClose( ){ int rc = SQLITE_OK; if( pWal ){ + int isDelete = 0; /* True to unlink wal and wal-index files */ + + /* If an EXCLUSIVE lock can be obtained on the database file (using the + ** ordinary, rollback-mode locking methods, this guarantees that the + ** connection associated with this log file is the only connection to + ** the database. In this case checkpoint the database and unlink both + ** the wal and wal-index files. + ** + ** The EXCLUSIVE lock is not released before returning. + */ + rc = sqlite3OsLock(pFd, SQLITE_LOCK_EXCLUSIVE); + if( rc==SQLITE_OK ){ + rc = walCheckpoint(pWal, pFd, sync_flags, zBuf); + if( rc==SQLITE_OK ){ + isDelete = 1; + } + walIndexUnmap(pWal); + } + pWal->pVfs->xShmClose(pWal->pWIndex); sqlite3OsClose(pWal->pFd); + if( isDelete ){ + int nWal; + char *zWal = &((char *)pWal->pFd)[pWal->pVfs->szOsFile]; + sqlite3OsDelete(pWal->pVfs, zWal, 0); + nWal = sqlite3Strlen30(zWal); + memcpy(&zWal[nWal], "-index", 7); + pWal->pVfs->xShmDelete(pWal->pVfs, zWal); + } sqlite3_free(pWal); } return rc; @@ -1008,6 +1035,23 @@ int sqlite3WalWriteLock(Wal *pWal, int op){ if( op ){ assert( pWal->lockState == SQLITE_SHM_READ ); rc = walSetLock(pWal, SQLITE_SHM_WRITE); + + /* If this connection is not reading the most recent database snapshot, + ** it is not possible to write to the database. In this case release + ** the write locks and return SQLITE_BUSY. + */ + if( rc==SQLITE_OK ){ + rc = walIndexMap(pWal, -1); + if( rc==SQLITE_OK + && memcmp(&pWal->hdr, pWal->pWiData, sizeof(WalIndexHdr)) + ){ + rc = SQLITE_BUSY; + } + walIndexUnmap(pWal); + if( rc!=SQLITE_OK ){ + walSetLock(pWal, SQLITE_SHM_READ); + } + } }else if( pWal->lockState==SQLITE_SHM_WRITE ){ rc = walSetLock(pWal, SQLITE_SHM_READ); } |