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Overview
Comment: | Add evidence marks and assert()s used as evidence for checkpoint requirements. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
b2da8afc7657266fbe8e683c6e50fe18 |
User & Date: | drh 2014-12-03 19:25:41.425 |
Context
2014-12-04
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04:50 | Add an implementation mark and fix a comment describing the OP_Checkpoint opcode. (check-in: 7475b90c55 user: drh tags: trunk) | |
2014-12-03
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19:25 | Add evidence marks and assert()s used as evidence for checkpoint requirements. (check-in: b2da8afc76 user: drh tags: trunk) | |
19:08 | Fix over-length comment lines in sqlite.h.in. No changes to code. (check-in: cbd357fd8c user: drh tags: trunk) | |
Changes
Changes to src/pager.c.
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7071 7072 7073 7074 7075 7076 7077 | ** ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART. */ int sqlite3PagerCheckpoint(Pager *pPager, int eMode, int *pnLog, int *pnCkpt){ int rc = SQLITE_OK; if( pPager->pWal ){ rc = sqlite3WalCheckpoint(pPager->pWal, eMode, | > | | 7071 7072 7073 7074 7075 7076 7077 7078 7079 7080 7081 7082 7083 7084 7085 7086 | ** ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART. */ int sqlite3PagerCheckpoint(Pager *pPager, int eMode, int *pnLog, int *pnCkpt){ int rc = SQLITE_OK; if( pPager->pWal ){ rc = sqlite3WalCheckpoint(pPager->pWal, eMode, (eMode==SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler), pPager->pBusyHandlerArg, pPager->ckptSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace, pnLog, pnCkpt ); } return rc; } |
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Changes to src/wal.c.
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1685 1686 1687 1688 1689 1690 1691 | ** The caller must be holding sufficient locks to ensure that no other ** checkpoint is running (in any other thread or process) at the same ** time. */ static int walCheckpoint( Wal *pWal, /* Wal connection */ int eMode, /* One of PASSIVE, FULL or RESTART */ | | < > > | | 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 | ** The caller must be holding sufficient locks to ensure that no other ** checkpoint is running (in any other thread or process) at the same ** time. */ static int walCheckpoint( Wal *pWal, /* Wal connection */ int eMode, /* One of PASSIVE, FULL or RESTART */ int (*xBusy)(void*), /* Function to call when busy */ void *pBusyArg, /* Context argument for xBusyHandler */ int sync_flags, /* Flags for OsSync() (or 0) */ u8 *zBuf /* Temporary buffer to use */ ){ int rc; /* Return code */ int szPage; /* Database page-size */ WalIterator *pIter = 0; /* Wal iterator context */ u32 iDbpage = 0; /* Next database page to write */ u32 iFrame = 0; /* Wal frame containing data for iDbpage */ u32 mxSafeFrame; /* Max frame that can be backfilled */ u32 mxPage; /* Max database page to write */ int i; /* Loop counter */ volatile WalCkptInfo *pInfo; /* The checkpoint status information */ szPage = walPagesize(pWal); testcase( szPage<=32768 ); testcase( szPage>=65536 ); pInfo = walCkptInfo(pWal); if( pInfo->nBackfill>=pWal->hdr.mxFrame ) return SQLITE_OK; /* Allocate the iterator */ rc = walIteratorInit(pWal, &pIter); if( rc!=SQLITE_OK ){ return rc; } assert( pIter ); /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked ** in the SQLITE_CHECKPOINT_PASSIVE mode. */ assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 ); /* Compute in mxSafeFrame the index of the last frame of the WAL that is ** safe to write into the database. Frames beyond mxSafeFrame might ** overwrite database pages that are in use by active readers and thus ** cannot be backfilled from the WAL. */ mxSafeFrame = pWal->hdr.mxFrame; |
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2939 2940 2941 2942 2943 2944 2945 | ** we can from WAL into the database. ** ** If parameter xBusy is not NULL, it is a pointer to a busy-handler ** callback. In this case this function runs a blocking checkpoint. */ int sqlite3WalCheckpoint( Wal *pWal, /* Wal connection */ | | > > > > > > > > | | | > > > > > > | < | | > | < | > | | 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 | ** we can from WAL into the database. ** ** If parameter xBusy is not NULL, it is a pointer to a busy-handler ** callback. In this case this function runs a blocking checkpoint. */ int sqlite3WalCheckpoint( Wal *pWal, /* Wal connection */ int eMode, /* PASSIVE, FULL, RESTART, or TRUNCATE */ int (*xBusy)(void*), /* Function to call when busy */ void *pBusyArg, /* Context argument for xBusyHandler */ int sync_flags, /* Flags to sync db file with (or 0) */ int nBuf, /* Size of temporary buffer */ u8 *zBuf, /* Temporary buffer to use */ int *pnLog, /* OUT: Number of frames in WAL */ int *pnCkpt /* OUT: Number of backfilled frames in WAL */ ){ int rc; /* Return code */ int isChanged = 0; /* True if a new wal-index header is loaded */ int eMode2 = eMode; /* Mode to pass to walCheckpoint() */ int (*xBusy2)(void*) = xBusy; /* Busy handler for eMode2 */ assert( pWal->ckptLock==0 ); assert( pWal->writeLock==0 ); /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked ** in the SQLITE_CHECKPOINT_PASSIVE mode. */ assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 ); if( pWal->readOnly ) return SQLITE_READONLY; WALTRACE(("WAL%p: checkpoint begins\n", pWal)); /* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive ** "checkpoint" lock on the database file. */ rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1); if( rc ){ /* EVIDENCE-OF: R-10421-19736 If any other process is running a ** checkpoint operation at the same time, the lock cannot be obtained and ** SQLITE_BUSY is returned. ** EVIDENCE-OF: R-53820-33897 Even if there is a busy-handler configured, ** it will not be invoked in this case. */ testcase( rc==SQLITE_BUSY ); testcase( xBusy!=0 ); return rc; } pWal->ckptLock = 1; /* IMPLEMENTATION-OF: R-59782-36818 The SQLITE_CHECKPOINT_FULL, RESTART and ** TRUNCATE modes also obtain the exclusive "writer" lock on the database ** file. ** ** EVIDENCE-OF: R-60642-04082 If the writer lock cannot be obtained ** immediately, and a busy-handler is configured, it is invoked and the ** writer lock retried until either the busy-handler returns 0 or the ** lock is successfully obtained. */ if( eMode!=SQLITE_CHECKPOINT_PASSIVE ){ rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_WRITE_LOCK, 1); if( rc==SQLITE_OK ){ pWal->writeLock = 1; }else if( rc==SQLITE_BUSY ){ eMode2 = SQLITE_CHECKPOINT_PASSIVE; xBusy2 = 0; rc = SQLITE_OK; } } /* Read the wal-index header. */ if( rc==SQLITE_OK ){ rc = walIndexReadHdr(pWal, &isChanged); if( isChanged && pWal->pDbFd->pMethods->iVersion>=3 ){ sqlite3OsUnfetch(pWal->pDbFd, 0, 0); } } /* Copy data from the log to the database file. */ if( rc==SQLITE_OK ){ if( pWal->hdr.mxFrame && walPagesize(pWal)!=nBuf ){ rc = SQLITE_CORRUPT_BKPT; }else{ rc = walCheckpoint(pWal, eMode2, xBusy2, pBusyArg, sync_flags, zBuf); } /* If no error occurred, set the output variables. */ if( rc==SQLITE_OK || rc==SQLITE_BUSY ){ if( pnLog ) *pnLog = (int)pWal->hdr.mxFrame; if( pnCkpt ) *pnCkpt = (int)(walCkptInfo(pWal)->nBackfill); } |
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