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Overview
Comment: | Remove code for PLL support in wal mode from this branch. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | server-process-edition |
Files: | files | file ages | folders |
SHA3-256: |
8e1b28ed3e83eba0b2113316a40ed116 |
User & Date: | dan 2017-08-14 07:16:18.805 |
Context
2017-08-16
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16:52 | Enhance this branch to support page-level-locking (without MVCC) for multi-process deployments. (check-in: 04e0cb571d user: dan tags: server-process-edition) | |
2017-08-14
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07:16 | Remove code for PLL support in wal mode from this branch. (check-in: 8e1b28ed3e user: dan tags: server-process-edition) | |
06:55 | Update this branch with latest trunk changes. (check-in: bc2498d60f user: dan tags: server-process-edition) | |
Changes
Changes to src/pager.c.
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7690 7691 7692 7693 7694 7695 7696 | /* Close any rollback journal previously open */ sqlite3OsClose(pPager->jfd); rc = pagerOpenWal(pPager); if( rc==SQLITE_OK ){ pPager->journalMode = PAGER_JOURNALMODE_WAL; pPager->eState = PAGER_OPEN; | < < < | 7690 7691 7692 7693 7694 7695 7696 7697 7698 7699 7700 7701 7702 7703 | /* Close any rollback journal previously open */ sqlite3OsClose(pPager->jfd); rc = pagerOpenWal(pPager); if( rc==SQLITE_OK ){ pPager->journalMode = PAGER_JOURNALMODE_WAL; pPager->eState = PAGER_OPEN; } }else{ *pbOpen = 1; } return rc; } |
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Changes to src/wal.c.
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450 451 452 453 454 455 456 | u32 nCkpt; /* Checkpoint sequence counter in the wal-header */ #ifdef SQLITE_DEBUG u8 lockError; /* True if a locking error has occurred */ #endif #ifdef SQLITE_ENABLE_SNAPSHOT WalIndexHdr *pSnapshot; /* Start transaction here if not NULL */ #endif | < < < < < < < < < | 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 | u32 nCkpt; /* Checkpoint sequence counter in the wal-header */ #ifdef SQLITE_DEBUG u8 lockError; /* True if a locking error has occurred */ #endif #ifdef SQLITE_ENABLE_SNAPSHOT WalIndexHdr *pSnapshot; /* Start transaction here if not NULL */ #endif }; /* ** Candidate values for Wal.exclusiveMode. */ #define WAL_NORMAL_MODE 0 #define WAL_EXCLUSIVE_MODE 1 #define WAL_HEAPMEMORY_MODE 2 |
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1266 1267 1268 1269 1270 1271 1272 | pWal->apWiData[i] = 0; } }else{ sqlite3OsShmUnmap(pWal->pDbFd, isDelete); } } | < < < < < < < < | 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 | pWal->apWiData[i] = 0; } }else{ sqlite3OsShmUnmap(pWal->pDbFd, isDelete); } } /* ** Open a connection to the WAL file zWalName. The database file must ** already be opened on connection pDbFd. The buffer that zWalName points ** to must remain valid for the lifetime of the returned Wal* handle. ** ** A SHARED lock should be held on the database file when this function ** is called. The purpose of this SHARED lock is to prevent any other |
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1905 1906 1907 1908 1909 1910 1911 | ** checkpointed and behave accordingly. This seems unsafe though, ** as it would leave the system in a state where the contents of ** the wal-index header do not match the contents of the ** file-system. To avoid this, update the wal-index header to ** indicate that the log file contains zero valid frames. */ walRestartHdr(pWal, salt1); rc = sqlite3OsTruncate(pWal->pWalFd, 0); | < < < | 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 | ** checkpointed and behave accordingly. This seems unsafe though, ** as it would leave the system in a state where the contents of ** the wal-index header do not match the contents of the ** file-system. To avoid this, update the wal-index header to ** indicate that the log file contains zero valid frames. */ walRestartHdr(pWal, salt1); rc = sqlite3OsTruncate(pWal->pWalFd, 0); } walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1); } } } walcheckpoint_out: |
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2067 2068 2069 2070 2071 2072 2073 | testcase( pWal->szPage>=65536 ); } /* The header was successfully read. Return zero. */ return 0; } | < < < < < < < < | 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 | testcase( pWal->szPage>=65536 ); } /* The header was successfully read. Return zero. */ return 0; } /* ** Read the wal-index header from the wal-index and into pWal->hdr. ** If the wal-header appears to be corrupt, try to reconstruct the ** wal-index from the WAL before returning. ** ** Set *pChanged to 1 if the wal-index header value in pWal->hdr is ** changed by this operation. If pWal->hdr is unchanged, set *pChanged |
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2115 2116 2117 2118 2119 2120 2121 | /* If the first attempt failed, it might have been due to a race ** with a writer. So get a WRITE lock and try again. */ assert( badHdr==0 || pWal->writeLock==0 ); if( badHdr ){ if( pWal->readOnly & WAL_SHM_RDONLY ){ | < | < | < | 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 | /* If the first attempt failed, it might have been due to a race ** with a writer. So get a WRITE lock and try again. */ assert( badHdr==0 || pWal->writeLock==0 ); if( badHdr ){ if( pWal->readOnly & WAL_SHM_RDONLY ){ if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){ walUnlockShared(pWal, WAL_WRITE_LOCK); rc = SQLITE_READONLY_RECOVERY; } }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){ pWal->writeLock = 1; if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){ badHdr = walIndexTryHdr(pWal, pChanged); if( badHdr ){ /* If the wal-index header is still malformed even while holding ** a WRITE lock, it can only mean that the header is corrupted and ** needs to be reconstructed. So run recovery to do exactly that. */ rc = walIndexRecover(pWal); *pChanged = 1; } } pWal->writeLock = 0; walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1); } } /* If the header is read successfully, check the version number to make ** sure the wal-index was not constructed with some future format that ** this version of SQLite cannot understand. */ |
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2276 2277 2278 2279 2280 2281 2282 | } } if( rc!=SQLITE_OK ){ return rc; } } | < < < | 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 | } } if( rc!=SQLITE_OK ){ return rc; } } pInfo = walCkptInfo(pWal); if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame #ifdef SQLITE_ENABLE_SNAPSHOT && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0 || 0==memcmp(&pWal->hdr, pWal->pSnapshot, sizeof(WalIndexHdr))) #endif ){ |
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2618 2619 2620 2621 2622 2623 2624 | ){ u32 iRead = 0; /* If !=0, WAL frame to return data from */ u32 iLast = pWal->hdr.mxFrame; /* Last page in WAL for this reader */ int iHash; /* Used to loop through N hash tables */ int iMinHash; /* This routine is only be called from within a read transaction. */ | | < < < < < < < < | 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 | ){ u32 iRead = 0; /* If !=0, WAL frame to return data from */ u32 iLast = pWal->hdr.mxFrame; /* Last page in WAL for this reader */ int iHash; /* Used to loop through N hash tables */ int iMinHash; /* This routine is only be called from within a read transaction. */ assert( pWal->readLock>=0 || pWal->lockError ); /* If the "last page" field of the wal-index header snapshot is 0, then ** no data will be read from the wal under any circumstances. Return early ** in this case as an optimization. Likewise, if pWal->readLock==0, ** then the WAL is ignored by the reader so return early, as if the ** WAL were empty. */ |
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2738 2739 2740 2741 2742 2743 2744 | return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset); } /* ** Return the size of the database in pages (or zero, if unknown). */ Pgno sqlite3WalDbsize(Wal *pWal){ | | | 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 | return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset); } /* ** Return the size of the database in pages (or zero, if unknown). */ Pgno sqlite3WalDbsize(Wal *pWal){ if( pWal && ALWAYS(pWal->readLock>=0) ){ return pWal->hdr.nPage; } return 0; } /* |
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2763 2764 2765 2766 2767 2768 2769 | ** There can only be a single writer active at a time. */ int sqlite3WalBeginWriteTransaction(Wal *pWal){ int rc; /* Cannot start a write transaction without first holding a read ** transaction. */ | | < < < < < | 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 | ** There can only be a single writer active at a time. */ int sqlite3WalBeginWriteTransaction(Wal *pWal){ int rc; /* Cannot start a write transaction without first holding a read ** transaction. */ assert( pWal->readLock>=0 ); assert( pWal->writeLock==0 && pWal->iReCksum==0 ); if( pWal->readOnly ){ return SQLITE_READONLY; } /* Only one writer allowed at a time. Get the write lock. Return ** SQLITE_BUSY if unable. */ rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1); if( rc ){ return rc; } |
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2825 2826 2827 2828 2829 2830 2831 | ** returned to the caller. ** ** Otherwise, if the callback function does not return an error, this ** function returns SQLITE_OK. */ int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){ int rc = SQLITE_OK; | | | 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 | ** returned to the caller. ** ** Otherwise, if the callback function does not return an error, this ** function returns SQLITE_OK. */ int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){ int rc = SQLITE_OK; if( ALWAYS(pWal->writeLock) ){ Pgno iMax = pWal->hdr.mxFrame; Pgno iFrame; /* Restore the clients cache of the wal-index header to the state it ** was in before the client began writing to the database. */ memcpy(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr)); |
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2915 2916 2917 2918 2919 2920 2921 | ** unchanged. ** ** SQLITE_OK is returned if no error is encountered (regardless of whether ** or not pWal->hdr.mxFrame is modified). An SQLite error code is returned ** if an error occurs. */ static int walRestartLog(Wal *pWal){ | < | | < | 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 | ** unchanged. ** ** SQLITE_OK is returned if no error is encountered (regardless of whether ** or not pWal->hdr.mxFrame is modified). An SQLite error code is returned ** if an error occurs. */ static int walRestartLog(Wal *pWal){ int rc = SQLITE_OK; int cnt; if( pWal->readLock==0 ){ volatile WalCkptInfo *pInfo = walCkptInfo(pWal); assert( pInfo->nBackfill==pWal->hdr.mxFrame ); if( pInfo->nBackfill>0 ){ u32 salt1; sqlite3_randomness(4, &salt1); rc = walLockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1); if( rc==SQLITE_OK ){ /* If all readers are using WAL_READ_LOCK(0) (in other words if no |
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2943 2944 2945 2946 2947 2948 2949 | ** to handle if this transaction is rolled back. */ walRestartHdr(pWal, salt1); walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1); }else if( rc!=SQLITE_BUSY ){ return rc; } } | < | 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 | ** to handle if this transaction is rolled back. */ walRestartHdr(pWal, salt1); walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1); }else if( rc!=SQLITE_BUSY ){ return rc; } } walUnlockShared(pWal, WAL_READ_LOCK(0)); pWal->readLock = -1; cnt = 0; do{ int notUsed; rc = walTryBeginRead(pWal, ¬Used, 1, ++cnt); }while( rc==WAL_RETRY ); |
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3104 3105 3106 3107 3108 3109 3110 | int szFrame; /* The size of a single frame */ i64 iOffset; /* Next byte to write in WAL file */ WalWriter w; /* The writer */ u32 iFirst = 0; /* First frame that may be overwritten */ WalIndexHdr *pLive; /* Pointer to shared header */ assert( pList ); | | < < < < < < < < < < < < < < < < | | 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 | int szFrame; /* The size of a single frame */ i64 iOffset; /* Next byte to write in WAL file */ WalWriter w; /* The writer */ u32 iFirst = 0; /* First frame that may be overwritten */ WalIndexHdr *pLive; /* Pointer to shared header */ assert( pList ); assert( pWal->writeLock ); /* If this frame set completes a transaction, then nTruncate>0. If ** nTruncate==0 then this frame set does not complete the transaction. */ assert( (isCommit!=0)==(nTruncate!=0) ); #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG) { int cnt; for(cnt=0, p=pList; p; p=p->pDirty, cnt++){} WALTRACE(("WAL%p: frame write begin. %d frames. mxFrame=%d. %s\n", pWal, cnt, pWal->hdr.mxFrame, isCommit ? "Commit" : "Spill")); } #endif pLive = (WalIndexHdr*)walIndexHdr(pWal); if( memcmp(&pWal->hdr, (void *)pLive, sizeof(WalIndexHdr))!=0 ){ iFirst = pLive->mxFrame+1; } /* See if it is possible to write these frames into the start of the ** log file, instead of appending to it at pWal->hdr.mxFrame. */ if( SQLITE_OK!=(rc = walRestartLog(pWal)) ){ return rc; } /* If this is the first frame written into the log, write the WAL ** header to the start of the WAL file. See comments at the top of ** this source file for a description of the WAL header format. */ |
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3393 3394 3395 3396 3397 3398 3399 | ** ** 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 ){ | < < < < < < < < < < < | < | 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 | ** ** 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; } |
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3450 3451 3452 3453 3454 3455 3456 | ** next time the pager opens a snapshot on this database it knows that ** the cache needs to be reset. */ memset(&pWal->hdr, 0, sizeof(WalIndexHdr)); } /* Release the locks. */ | < < | 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 | ** next time the pager opens a snapshot on this database it knows that ** the cache needs to be reset. */ memset(&pWal->hdr, 0, sizeof(WalIndexHdr)); } /* Release the locks. */ sqlite3WalEndWriteTransaction(pWal); walUnlockExclusive(pWal, WAL_CKPT_LOCK, 1); pWal->ckptLock = 0; WALTRACE(("WAL%p: checkpoint %s\n", pWal, rc ? "failed" : "ok")); return (rc==SQLITE_OK && eMode!=eMode2 ? SQLITE_BUSY : rc); } /* Return the value to pass to a sqlite3_wal_hook callback, the ** number of frames in the WAL at the point of the last commit since ** sqlite3WalCallback() was called. If no commits have occurred since ** the last call, then return 0. |
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