From: drh Date: Tue, 2 Oct 2018 19:36:40 +0000 (+0000) Subject: Fix comments and refactor some names associated with shared-memory locking X-Git-Tag: version-3.26.0~105 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=24efa5444df0378c8747ffc8e53ea2e126532ba1;p=thirdparty%2Fsqlite.git Fix comments and refactor some names associated with shared-memory locking in the Unix VFS. No logical changes. FossilOrigin-Name: 3e9f1635271c92dce5324728b4ee1cc1a1856ec3c60b1b512a652c21e010e63e --- diff --git a/manifest b/manifest index 87e0657611..8f36e316da 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Add\sthe\s"PRAGMA\stable_xinfo"\scommand\sthat\sworks\slike\stable_info\sbut\salso\nshows\shidden\scolumns\sin\svirtual\stables\sand\sadds\sthe\s"hidden"\sboolean\scolumn. -D 2018-10-01T21:41:15.265 +C Fix\scomments\sand\srefactor\ssome\snames\sassociated\swith\sshared-memory\slocking\nin\sthe\sUnix\sVFS.\s\sNo\slogical\schanges. +D 2018-10-02T19:36:40.212 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea F Makefile.in 01e95208a78b57d056131382c493c963518f36da4c42b12a97eb324401b3a334 @@ -487,7 +487,7 @@ F src/os.c 8aeb0b0f40f8f5b0da03fe49706695adaf42d2f516ab95abc72e86c245e119de F src/os.h 48388821692e87da174ea198bf96b1b2d9d83be5dfc908f673ee21fafbe0d432 F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85 F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586 -F src/os_unix.c 7cfd67db0e2f926243f646db7ec1caa33ca9bee45799b0160ddfcd6ccfc175d2 +F src/os_unix.c 3acd41af1334d7d2af8ca8ce684ccc73eeab7fe907ddab630963fd54102b4be4 F src/os_win.c 070cdbb400097c6cda54aa005356095afdc2f3ee691d17192c54724ef146a971 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a F src/pager.c a0d8f686ef64549ad5b356fd30429bd9ee7a06dd42b4d6faa096352ff26b1c5b @@ -1770,8 +1770,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0 -P 310b4b65b8c8ee080760c7efb4c7e20244c6063a5dba37a4f40490105aafd29f 7694b9bc3003db6ba0b41c5029c8f7b84c07724e7a518e835e98b3c46e4ea227 -R 4421b937cd53dd313f71ab5caa0a0109 -T +closed 7694b9bc3003db6ba0b41c5029c8f7b84c07724e7a518e835e98b3c46e4ea227 +P defa0515b8fd50ed9be699542f8c6695dd4a60c02f310665db6657ec5b6b67d0 +R 9097a8d83ca39760ec0a01128c0dade1 U drh -Z e0b06ff9de331820a7420ba45b53f562 +Z 3fc014f602248e5c82ae5fe3e9828c74 diff --git a/manifest.uuid b/manifest.uuid index b4be3bca8b..31f7167738 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -defa0515b8fd50ed9be699542f8c6695dd4a60c02f310665db6657ec5b6b67d0 \ No newline at end of file +3e9f1635271c92dce5324728b4ee1cc1a1856ec3c60b1b512a652c21e010e63e \ No newline at end of file diff --git a/src/os_unix.c b/src/os_unix.c index 6a1195041b..b0e5f825dc 100644 --- a/src/os_unix.c +++ b/src/os_unix.c @@ -136,12 +136,10 @@ #define SQLITE_FSFLAGS_IS_MSDOS 0x1 /* -** If we are to be thread-safe, include the pthreads header and define -** the SQLITE_UNIX_THREADS macro. +** If we are to be thread-safe, include the pthreads header. */ #if SQLITE_THREADSAFE # include -# define SQLITE_UNIX_THREADS 1 #endif /* @@ -1119,8 +1117,7 @@ struct unixFileId { /* ** 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. +** inode. ** ** A single inode can have multiple file descriptors, so each unixFile ** structure contains a pointer to an instance of this object and this @@ -1166,13 +1163,16 @@ struct unixInodeInfo { /* ** A lists of all unixInodeInfo objects. +** +** Must hold unixBigLock in order to read or write this variable. */ static unixInodeInfo *inodeList = 0; /* All unixInodeInfo objects */ #ifdef SQLITE_DEBUG /* -** True if the inode mutex is held, or not. Used only within assert() -** to help verify correct mutex usage. +** True if the inode mutex (on the unixFile.pFileMutex field) is held, or not. +** This routine is used only within assert() to help verify correct mutex +** usage. */ int unixFileMutexHeld(unixFile *pFile){ assert( pFile->pInode ); @@ -1300,8 +1300,8 @@ static void closePendingFds(unixFile *pFile){ /* ** Release a unixInodeInfo structure previously allocated by findInodeInfo(). ** -** The mutex entered using the unixEnterMutex() function must be held -** when this function is called. +** The global mutex must be held when this routine is called, but the mutex +** on the inode being deleted must NOT be held. */ static void releaseInodeInfo(unixFile *pFile){ unixInodeInfo *pInode = pFile->pInode; @@ -1336,8 +1336,7 @@ static void releaseInodeInfo(unixFile *pFile){ ** describes that file descriptor. Create a new one if necessary. The ** return value might be uninitialized if an error occurs. ** -** The mutex entered using the unixEnterMutex() function must be held -** when this function is called. +** The global mutex must held when calling this routine. ** ** Return an appropriate error code. */ @@ -1398,6 +1397,7 @@ static int findInodeInfo( #else fileId.ino = (u64)statbuf.st_ino; #endif + assert( unixMutexHeld() ); pInode = inodeList; while( pInode && memcmp(&fileId, &pInode->fileId, sizeof(fileId)) ){ pInode = pInode->pNext; @@ -1417,6 +1417,7 @@ static int findInodeInfo( } } pInode->nRef = 1; + assert( unixMutexHeld() ); pInode->pNext = inodeList; pInode->pPrev = 0; if( inodeList ) inodeList->pPrev = pInode; @@ -4223,7 +4224,7 @@ static int unixGetpagesize(void){ */ struct unixShmNode { unixInodeInfo *pInode; /* unixInodeInfo that owns this SHM node */ - sqlite3_mutex *mutex; /* Mutex to access this object */ + sqlite3_mutex *pShmMutex; /* Mutex to access this object */ char *zFilename; /* Name of the mmapped file */ int h; /* Open file descriptor */ int szRegion; /* Size of shared-memory regions */ @@ -4247,16 +4248,16 @@ struct unixShmNode { ** The following fields are initialized when this object is created and ** are read-only thereafter: ** -** unixShm.pFile +** unixShm.pShmNode ** unixShm.id ** -** All other fields are read/write. The unixShm.pFile->mutex must be held -** while accessing any read/write fields. +** All other fields are read/write. The unixShm.pShmNode->pShmMutex must +** be held while accessing any read/write fields. */ struct unixShm { unixShmNode *pShmNode; /* The underlying unixShmNode object */ unixShm *pNext; /* Next unixShm with the same unixShmNode */ - u8 hasMutex; /* True if holding the unixShmNode mutex */ + u8 hasMutex; /* True if holding the unixShmNode->pShmMutex */ u8 id; /* Id of this connection within its unixShmNode */ u16 sharedMask; /* Mask of shared locks held */ u16 exclMask; /* Mask of exclusive locks held */ @@ -4286,7 +4287,7 @@ static int unixShmSystemLock( /* Access to the unixShmNode object is serialized by the caller */ pShmNode = pFile->pInode->pShmNode; - assert( pShmNode->nRef==0 || sqlite3_mutex_held(pShmNode->mutex) ); + assert( pShmNode->nRef==0 || sqlite3_mutex_held(pShmNode->pShmMutex) ); /* Shared locks never span more than one byte */ assert( n==1 || lockType!=F_RDLCK ); @@ -4372,7 +4373,7 @@ static void unixShmPurge(unixFile *pFd){ int nShmPerMap = unixShmRegionPerMap(); int i; assert( p->pInode==pFd->pInode ); - sqlite3_mutex_free(p->mutex); + sqlite3_mutex_free(p->pShmMutex); for(i=0; inRegion; i+=nShmPerMap){ if( p->h>=0 ){ osMunmap(p->apRegion[i], p->szRegion); @@ -4543,8 +4544,8 @@ static int unixOpenSharedMemory(unixFile *pDbFd){ pDbFd->pInode->pShmNode = pShmNode; pShmNode->pInode = pDbFd->pInode; if( sqlite3GlobalConfig.bCoreMutex ){ - pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST); - if( pShmNode->mutex==0 ){ + pShmNode->pShmMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST); + if( pShmNode->pShmMutex==0 ){ rc = SQLITE_NOMEM_BKPT; goto shm_open_err; } @@ -4587,13 +4588,13 @@ static int unixOpenSharedMemory(unixFile *pDbFd){ ** the cover of the unixEnterMutex() mutex and the pointer from the ** new (struct unixShm) object to the pShmNode has been set. All that is ** left to do is to link the new object into the linked list starting - ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex - ** mutex. + ** at pShmNode->pFirst. This must be done while holding the + ** pShmNode->pShmMutex. */ - sqlite3_mutex_enter(pShmNode->mutex); + sqlite3_mutex_enter(pShmNode->pShmMutex); p->pNext = pShmNode->pFirst; pShmNode->pFirst = p; - sqlite3_mutex_leave(pShmNode->mutex); + sqlite3_mutex_leave(pShmNode->pShmMutex); return rc; /* Jump here on any error */ @@ -4645,7 +4646,7 @@ static int unixShmMap( p = pDbFd->pShm; pShmNode = p->pShmNode; - sqlite3_mutex_enter(pShmNode->mutex); + sqlite3_mutex_enter(pShmNode->pShmMutex); if( pShmNode->isUnlocked ){ rc = unixLockSharedMemory(pDbFd, pShmNode); if( rc!=SQLITE_OK ) goto shmpage_out; @@ -4754,7 +4755,7 @@ shmpage_out: *pp = 0; } if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY; - sqlite3_mutex_leave(pShmNode->mutex); + sqlite3_mutex_leave(pShmNode->pShmMutex); return rc; } @@ -4793,7 +4794,7 @@ static int unixShmLock( mask = (1<<(ofst+n)) - (1<1 || mask==(1<mutex); + sqlite3_mutex_enter(pShmNode->pShmMutex); if( flags & SQLITE_SHM_UNLOCK ){ u16 allMask = 0; /* Mask of locks held by siblings */ @@ -4866,7 +4867,7 @@ static int unixShmLock( } } } - sqlite3_mutex_leave(pShmNode->mutex); + sqlite3_mutex_leave(pShmNode->pShmMutex); OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x\n", p->id, osGetpid(0), p->sharedMask, p->exclMask)); return rc; @@ -4916,14 +4917,14 @@ static int unixShmUnmap( /* Remove connection p from the set of connections associated ** with pShmNode */ - sqlite3_mutex_enter(pShmNode->mutex); + sqlite3_mutex_enter(pShmNode->pShmMutex); for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){} *pp = p->pNext; /* Free the connection p */ sqlite3_free(p); pDbFd->pShm = 0; - sqlite3_mutex_leave(pShmNode->mutex); + sqlite3_mutex_leave(pShmNode->pShmMutex); /* If pShmNode->nRef has reached 0, then close the underlying ** shared-memory file, too */