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Changes In Branch separate-lock-mutex Excluding Merge-Ins
This is equivalent to a diff from 8607b84a to 1c948348
2018-07-26
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21:48 | In the unix VFS, give every unixInodeInfo object its own mutex, rather than using the global VFS mutex, to improve concurrency in cases where there are many threads operating on separate database files. (check-in: 22f47cf4 user: drh tags: trunk) | |
2018-07-24
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13:57 | Add missing SQLITE_OMIT_WINDOWFUNC check to the json1 extension. (check-in: fe19f823 user: mistachkin tags: trunk) | |
2018-07-23
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22:55 | Return an SQLITE_NOMEM error if the locking mutex fails to allocate. (Closed-Leaf check-in: 1c948348 user: drh tags: separate-lock-mutex) | |
21:10 | First attempt at reducing mutex contention in the unix VFS by providing a separate mutex for each unixInodeInfo object. (check-in: f69afaf0 user: drh tags: separate-lock-mutex) | |
18:53 | Fix typo of 'SQLITE_OMIT_WINDOWFUNC'. (check-in: 8607b84a user: mistachkin tags: trunk) | |
18:32 | Attempt to improve the documentation for snapshots. No changes to code. (check-in: 46dd076a user: drh tags: trunk) | |
Changes to src/os_unix.c.
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1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 | ** An instance of the following structure is allocated for each open ** inode. Or, on LinuxThreads, there is one of these structures for ** each inode opened by each thread. ** ** A single inode can have multiple file descriptors, so each unixFile ** structure contains a pointer to an instance of this object and this ** object keeps a count of the number of unixFile pointing to it. */ struct unixInodeInfo { struct unixFileId fileId; /* The lookup key */ | > > > > > > > > > > > > > > | > | | < | 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 | ** An instance of the following structure is allocated for each open ** inode. Or, on LinuxThreads, there is one of these structures for ** each inode opened by each thread. ** ** A single inode can have multiple file descriptors, so each unixFile ** structure contains a pointer to an instance of this object and this ** object keeps a count of the number of unixFile pointing to it. ** ** Mutex rules: ** ** (1) The pLockMutex mutex must be held in order to read or write ** any of the locking fields: ** nShared, nLock, eFileLock, or bProcessLock ** ** (2) When nRef>0, then the following fields are unchanging and can ** be read (but not written) without holding any mutex: ** fileId, pLockMutex ** ** (3) With the exceptions above, all the fields may only be read ** or written while holding the global unixBigLock mutex. */ struct unixInodeInfo { struct unixFileId fileId; /* The lookup key */ sqlite3_mutex *pLockMutex; /* Hold this mutex for... */ int nShared; /* Number of SHARED locks held */ int nLock; /* Number of outstanding file locks */ unsigned char eFileLock; /* One of SHARED_LOCK, RESERVED_LOCK etc. */ unsigned char bProcessLock; /* An exclusive process lock is held */ int nRef; /* Number of pointers to this structure */ unixShmNode *pShmNode; /* Shared memory associated with this inode */ UnixUnusedFd *pUnused; /* Unused file descriptors to close */ unixInodeInfo *pNext; /* List of all unixInodeInfo objects */ unixInodeInfo *pPrev; /* .... doubly linked */ #if SQLITE_ENABLE_LOCKING_STYLE unsigned long long sharedByte; /* for AFP simulated shared lock */ #endif #if OS_VXWORKS |
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1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 | assert( inodeList==pInode ); inodeList = pInode->pNext; } if( pInode->pNext ){ assert( pInode->pNext->pPrev==pInode ); pInode->pNext->pPrev = pInode->pPrev; } sqlite3_free(pInode); } } assert( inodeList!=0 || nUnusedFd==0 ); } /* | > | 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 | assert( inodeList==pInode ); inodeList = pInode->pNext; } if( pInode->pNext ){ assert( pInode->pNext->pPrev==pInode ); pInode->pNext->pPrev = pInode->pPrev; } sqlite3_mutex_free(pInode->pLockMutex); sqlite3_free(pInode); } } assert( inodeList!=0 || nUnusedFd==0 ); } /* |
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1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 | if( pInode==0 ){ pInode = sqlite3_malloc64( sizeof(*pInode) ); if( pInode==0 ){ return SQLITE_NOMEM_BKPT; } memset(pInode, 0, sizeof(*pInode)); memcpy(&pInode->fileId, &fileId, sizeof(fileId)); pInode->nRef = 1; pInode->pNext = inodeList; pInode->pPrev = 0; if( inodeList ) inodeList->pPrev = pInode; inodeList = pInode; }else{ pInode->nRef++; | > > > > > > > | 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 | if( pInode==0 ){ pInode = sqlite3_malloc64( sizeof(*pInode) ); if( pInode==0 ){ return SQLITE_NOMEM_BKPT; } memset(pInode, 0, sizeof(*pInode)); memcpy(&pInode->fileId, &fileId, sizeof(fileId)); if( sqlite3GlobalConfig.bCoreMutex ){ pInode->pLockMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST); if( pInode->pLockMutex==0 ){ sqlite3_free(pInode); return SQLITE_NOMEM_BKPT; } } pInode->nRef = 1; pInode->pNext = inodeList; pInode->pPrev = 0; if( inodeList ) inodeList->pPrev = pInode; inodeList = pInode; }else{ pInode->nRef++; |
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1432 1433 1434 1435 1436 1437 1438 | int reserved = 0; unixFile *pFile = (unixFile*)id; SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; ); assert( pFile ); assert( pFile->eFileLock<=SHARED_LOCK ); | | | 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 | int reserved = 0; unixFile *pFile = (unixFile*)id; SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; ); assert( pFile ); assert( pFile->eFileLock<=SHARED_LOCK ); sqlite3_mutex_enter(pFile->pInode->pLockMutex); /* Check if a thread in this process holds such a lock */ if( pFile->pInode->eFileLock>SHARED_LOCK ){ reserved = 1; } /* Otherwise see if some other process holds it. |
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1457 1458 1459 1460 1461 1462 1463 | storeLastErrno(pFile, errno); } else if( lock.l_type!=F_UNLCK ){ reserved = 1; } } #endif | | | 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 | storeLastErrno(pFile, errno); } else if( lock.l_type!=F_UNLCK ){ reserved = 1; } } #endif sqlite3_mutex_leave(pFile->pInode->pLockMutex); OSTRACE(("TEST WR-LOCK %d %d %d (unix)\n", pFile->h, rc, reserved)); *pResOut = reserved; return rc; } /* |
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1523 1524 1525 1526 1527 1528 1529 | ** ** Zero is returned if the call completes successfully, or -1 if a call ** to fcntl() fails. In this case, errno is set appropriately (by fcntl()). */ static int unixFileLock(unixFile *pFile, struct flock *pLock){ int rc; unixInodeInfo *pInode = pFile->pInode; | < > | 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 | ** ** Zero is returned if the call completes successfully, or -1 if a call ** to fcntl() fails. In this case, errno is set appropriately (by fcntl()). */ static int unixFileLock(unixFile *pFile, struct flock *pLock){ int rc; unixInodeInfo *pInode = pFile->pInode; assert( pInode!=0 ); assert( sqlite3_mutex_held(pInode->pLockMutex) ); if( (pFile->ctrlFlags & (UNIXFILE_EXCL|UNIXFILE_RDONLY))==UNIXFILE_EXCL ){ if( pInode->bProcessLock==0 ){ struct flock lock; assert( pInode->nLock==0 ); lock.l_whence = SEEK_SET; lock.l_start = SHARED_FIRST; lock.l_len = SHARED_SIZE; |
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1643 1644 1645 1646 1647 1648 1649 | */ assert( pFile->eFileLock!=NO_LOCK || eFileLock==SHARED_LOCK ); assert( eFileLock!=PENDING_LOCK ); assert( eFileLock!=RESERVED_LOCK || pFile->eFileLock==SHARED_LOCK ); /* This mutex is needed because pFile->pInode is shared across threads */ | < > | 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 | */ assert( pFile->eFileLock!=NO_LOCK || eFileLock==SHARED_LOCK ); assert( eFileLock!=PENDING_LOCK ); assert( eFileLock!=RESERVED_LOCK || pFile->eFileLock==SHARED_LOCK ); /* This mutex is needed because pFile->pInode is shared across threads */ pInode = pFile->pInode; sqlite3_mutex_enter(pInode->pLockMutex); /* If some thread using this PID has a lock via a different unixFile* ** handle that precludes the requested lock, return BUSY. */ if( (pFile->eFileLock!=pInode->eFileLock && (pInode->eFileLock>=PENDING_LOCK || eFileLock>SHARED_LOCK)) ){ |
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1787 1788 1789 1790 1791 1792 1793 | pInode->eFileLock = eFileLock; }else if( eFileLock==EXCLUSIVE_LOCK ){ pFile->eFileLock = PENDING_LOCK; pInode->eFileLock = PENDING_LOCK; } end_lock: | | | 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 | pInode->eFileLock = eFileLock; }else if( eFileLock==EXCLUSIVE_LOCK ){ pFile->eFileLock = PENDING_LOCK; pInode->eFileLock = PENDING_LOCK; } end_lock: sqlite3_mutex_leave(pInode->pLockMutex); OSTRACE(("LOCK %d %s %s (unix)\n", pFile->h, azFileLock(eFileLock), rc==SQLITE_OK ? "ok" : "failed")); return rc; } /* ** Add the file descriptor used by file handle pFile to the corresponding |
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1835 1836 1837 1838 1839 1840 1841 | pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared, osGetpid(0))); assert( eFileLock<=SHARED_LOCK ); if( pFile->eFileLock<=eFileLock ){ return SQLITE_OK; } | < > | 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 | pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared, osGetpid(0))); assert( eFileLock<=SHARED_LOCK ); if( pFile->eFileLock<=eFileLock ){ return SQLITE_OK; } pInode = pFile->pInode; sqlite3_mutex_enter(pInode->pLockMutex); assert( pInode->nShared!=0 ); if( pFile->eFileLock>SHARED_LOCK ){ assert( pInode->eFileLock==pFile->eFileLock ); #ifdef SQLITE_DEBUG /* When reducing a lock such that other processes can start ** reading the database file again, make sure that the |
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1968 1969 1970 1971 1972 1973 1974 | assert( pInode->nLock>=0 ); if( pInode->nLock==0 ){ closePendingFds(pFile); } } end_unlock: | | | 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 | assert( pInode->nLock>=0 ); if( pInode->nLock==0 ){ closePendingFds(pFile); } } end_unlock: sqlite3_mutex_leave(pInode->pLockMutex); if( rc==SQLITE_OK ) pFile->eFileLock = eFileLock; return rc; } /* ** Lower the locking level on file descriptor pFile to eFileLock. eFileLock ** must be either NO_LOCK or SHARED_LOCK. |
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2767 2768 2769 2770 2771 2772 2773 | assert( pFile ); context = (afpLockingContext *) pFile->lockingContext; if( context->reserved ){ *pResOut = 1; return SQLITE_OK; } | < | | 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 | assert( pFile ); context = (afpLockingContext *) pFile->lockingContext; if( context->reserved ){ *pResOut = 1; return SQLITE_OK; } sqlite3_mutex_enter(pFile->pInode->pLockMutex); /* Check if a thread in this process holds such a lock */ if( pFile->pInode->eFileLock>SHARED_LOCK ){ reserved = 1; } /* Otherwise see if some other process holds it. */ |
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2792 2793 2794 2795 2796 2797 2798 | reserved = 1; } if( IS_LOCK_ERROR(lrc) ){ rc=lrc; } } | | | 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 | reserved = 1; } if( IS_LOCK_ERROR(lrc) ){ rc=lrc; } } sqlite3_mutex_leave(pFile->pInode->pLockMutex); OSTRACE(("TEST WR-LOCK %d %d %d (afp)\n", pFile->h, rc, reserved)); *pResOut = reserved; return rc; } /* |
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2855 2856 2857 2858 2859 2860 2861 | */ assert( pFile->eFileLock!=NO_LOCK || eFileLock==SHARED_LOCK ); assert( eFileLock!=PENDING_LOCK ); assert( eFileLock!=RESERVED_LOCK || pFile->eFileLock==SHARED_LOCK ); /* This mutex is needed because pFile->pInode is shared across threads */ | < > | 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 | */ assert( pFile->eFileLock!=NO_LOCK || eFileLock==SHARED_LOCK ); assert( eFileLock!=PENDING_LOCK ); assert( eFileLock!=RESERVED_LOCK || pFile->eFileLock==SHARED_LOCK ); /* This mutex is needed because pFile->pInode is shared across threads */ pInode = pFile->pInode; sqlite3_mutex_enter(pInode->pLockMutex); /* If some thread using this PID has a lock via a different unixFile* ** handle that precludes the requested lock, return BUSY. */ if( (pFile->eFileLock!=pInode->eFileLock && (pInode->eFileLock>=PENDING_LOCK || eFileLock>SHARED_LOCK)) ){ |
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2992 2993 2994 2995 2996 2997 2998 | pInode->eFileLock = eFileLock; }else if( eFileLock==EXCLUSIVE_LOCK ){ pFile->eFileLock = PENDING_LOCK; pInode->eFileLock = PENDING_LOCK; } afp_end_lock: | | | 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 | pInode->eFileLock = eFileLock; }else if( eFileLock==EXCLUSIVE_LOCK ){ pFile->eFileLock = PENDING_LOCK; pInode->eFileLock = PENDING_LOCK; } afp_end_lock: sqlite3_mutex_leave(pInode->pLockMutex); OSTRACE(("LOCK %d %s %s (afp)\n", pFile->h, azFileLock(eFileLock), rc==SQLITE_OK ? "ok" : "failed")); return rc; } /* ** Lower the locking level on file descriptor pFile to eFileLock. eFileLock |
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3024 3025 3026 3027 3028 3029 3030 | pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared, osGetpid(0))); assert( eFileLock<=SHARED_LOCK ); if( pFile->eFileLock<=eFileLock ){ return SQLITE_OK; } | < > | 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 | pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared, osGetpid(0))); assert( eFileLock<=SHARED_LOCK ); if( pFile->eFileLock<=eFileLock ){ return SQLITE_OK; } pInode = pFile->pInode; sqlite3_mutex_enter(pInode->pLockMutex); assert( pInode->nShared!=0 ); if( pFile->eFileLock>SHARED_LOCK ){ assert( pInode->eFileLock==pFile->eFileLock ); SimulateIOErrorBenign(1); SimulateIOError( h=(-1) ) SimulateIOErrorBenign(0); |
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3100 3101 3102 3103 3104 3105 3106 | assert( pInode->nLock>=0 ); if( pInode->nLock==0 ){ closePendingFds(pFile); } } } | | | 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 | assert( pInode->nLock>=0 ); if( pInode->nLock==0 ){ closePendingFds(pFile); } } } sqlite3_mutex_leave(pInode->pLockMutex); if( rc==SQLITE_OK ) pFile->eFileLock = eFileLock; return rc; } /* ** Close a file & cleanup AFP specific locking context */ |
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