Index: src/main.c ================================================================== --- src/main.c +++ src/main.c @@ -2820,10 +2820,11 @@ }else if( flags & SQLITE_OPEN_FULLMUTEX ){ isThreadsafe = 1; }else{ isThreadsafe = sqlite3GlobalConfig.bFullMutex; } + if( flags & SQLITE_OPEN_PRIVATECACHE ){ flags &= ~SQLITE_OPEN_SHAREDCACHE; }else if( sqlite3GlobalConfig.sharedCacheEnabled ){ flags |= SQLITE_OPEN_SHAREDCACHE; } @@ -2852,17 +2853,24 @@ ); /* Allocate the sqlite data structure */ db = sqlite3MallocZero( sizeof(sqlite3) ); if( db==0 ) goto opendb_out; - if( isThreadsafe ){ + if( isThreadsafe +#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS + || sqlite3GlobalConfig.bCoreMutex +#endif + ){ db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE); if( db->mutex==0 ){ sqlite3_free(db); db = 0; goto opendb_out; } + if( isThreadsafe==0 ){ + sqlite3MutexWarnOnContention(db->mutex); + } } sqlite3_mutex_enter(db->mutex); db->errMask = 0xff; db->nDb = 2; db->magic = SQLITE_MAGIC_BUSY; Index: src/mutex.c ================================================================== --- src/mutex.c +++ src/mutex.c @@ -24,10 +24,197 @@ static SQLITE_WSD int mutexIsInit = 0; #endif /* SQLITE_DEBUG && !defined(SQLITE_MUTEX_OMIT) */ #ifndef SQLITE_MUTEX_OMIT + +#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS +/* +** This block (enclosed by SQLITE_ENABLE_MULTITHREADED_CHECKS) contains +** the implementation of a wrapper around the system default mutex +** implementation (sqlite3DefaultMutex()). +** +** Most calls are passed directly through to the underlying default +** mutex implementation. Except, if a mutex is configured by calling +** sqlite3MutexWarnOnContention() on it, then if contention is ever +** encountered within xMutexEnter() a warning is emitted via sqlite3_log(). +** +** This type of mutex is used as the database handle mutex when testing +** apps that usually use SQLITE_CONFIG_MULTITHREAD mode. +*/ + +/* +** Type for all mutexes used when SQLITE_ENABLE_MULTITHREADED_CHECKS +** is defined. Variable CheckMutex.mutex is a pointer to the real mutex +** allocated by the system mutex implementation. Variable iType is usually set +** to the type of mutex requested - SQLITE_MUTEX_RECURSIVE, SQLITE_MUTEX_FAST +** or one of the static mutex identifiers. Or, if this is a recursive mutex +** that has been configured using sqlite3MutexWarnOnContention(), it is +** set to SQLITE_MUTEX_WARNONCONTENTION. +*/ +typedef struct CheckMutex CheckMutex; +struct CheckMutex { + int iType; + sqlite3_mutex *mutex; +}; + +#define SQLITE_MUTEX_WARNONCONTENTION (-1) + +/* +** Pointer to real mutex methods object used by the CheckMutex +** implementation. Set by checkMutexInit(). +*/ +static SQLITE_WSD const sqlite3_mutex_methods *pGlobalMutexMethods; + +#ifdef SQLITE_DEBUG +static int checkMutexHeld(sqlite3_mutex *p){ + return pGlobalMutexMethods->xMutexHeld(((CheckMutex*)p)->mutex); +} +static int checkMutexNotheld(sqlite3_mutex *p){ + return pGlobalMutexMethods->xMutexNotheld(((CheckMutex*)p)->mutex); +} +#endif + +/* +** Initialize and deinitialize the mutex subsystem. +*/ +static int checkMutexInit(void){ + pGlobalMutexMethods = sqlite3DefaultMutex(); + return SQLITE_OK; +} +static int checkMutexEnd(void){ + pGlobalMutexMethods = 0; + return SQLITE_OK; +} + +/* +** Allocate a mutex. +*/ +static sqlite3_mutex *checkMutexAlloc(int iType){ + static CheckMutex staticMutexes[] = { + {2, 0}, {3, 0}, {4, 0}, {5, 0}, + {6, 0}, {7, 0}, {8, 0}, {9, 0}, + {10, 0}, {11, 0}, {12, 0}, {13, 0} + }; + CheckMutex *p = 0; + + assert( SQLITE_MUTEX_RECURSIVE==1 && SQLITE_MUTEX_FAST==0 ); + if( iType<2 ){ + p = sqlite3MallocZero(sizeof(CheckMutex)); + if( p==0 ) return 0; + p->iType = iType; + }else{ +#ifdef SQLITE_ENABLE_API_ARMOR + if( iType-2>=ArraySize(staticMutexes) ){ + (void)SQLITE_MISUSE_BKPT; + return 0; + } +#endif + p = &staticMutexes[iType-2]; + } + + if( p->mutex==0 ){ + p->mutex = pGlobalMutexMethods->xMutexAlloc(iType); + if( p->mutex==0 ){ + if( iType<2 ){ + sqlite3_free(p); + } + p = 0; + } + } + + return (sqlite3_mutex*)p; +} + +/* +** Free a mutex. +*/ +static void checkMutexFree(sqlite3_mutex *p){ + assert( SQLITE_MUTEX_RECURSIVE<2 ); + assert( SQLITE_MUTEX_FAST<2 ); + assert( SQLITE_MUTEX_WARNONCONTENTION<2 ); + +#if SQLITE_ENABLE_API_ARMOR + if( p->iType<2 ){ +#endif + { + CheckMutex *pCheck = (CheckMutex*)p; + pGlobalMutexMethods->xMutexFree(pCheck->mutex); + sqlite3_free(pCheck); + } +#ifdef SQLITE_ENABLE_API_ARMOR + else{ + (void)SQLITE_MISUSE_BKPT; + } +#endif +} + +/* +** Enter the mutex. +*/ +static void checkMutexEnter(sqlite3_mutex *p){ + CheckMutex *pCheck = (CheckMutex*)p; + if( pCheck->iType==SQLITE_MUTEX_WARNONCONTENTION ){ + if( SQLITE_OK==pGlobalMutexMethods->xMutexTry(pCheck->mutex) ){ + return; + } + sqlite3_log(SQLITE_MISUSE, + "illegal multi-threaded access to database connection" + ); + } + pGlobalMutexMethods->xMutexEnter(pCheck->mutex); +} + +/* +** Enter the mutex (do not block). +*/ +static int checkMutexTry(sqlite3_mutex *p){ + CheckMutex *pCheck = (CheckMutex*)p; + return pGlobalMutexMethods->xMutexTry(pCheck->mutex); +} + +/* +** Leave the mutex. +*/ +static void checkMutexLeave(sqlite3_mutex *p){ + CheckMutex *pCheck = (CheckMutex*)p; + pGlobalMutexMethods->xMutexLeave(pCheck->mutex); +} + +sqlite3_mutex_methods const *multiThreadedCheckMutex(void){ + static const sqlite3_mutex_methods sMutex = { + checkMutexInit, + checkMutexEnd, + checkMutexAlloc, + checkMutexFree, + checkMutexEnter, + checkMutexTry, + checkMutexLeave, +#ifdef SQLITE_DEBUG + checkMutexHeld, + checkMutexNotheld +#else + 0, + 0 +#endif + }; + return &sMutex; +} + +/* +** Mark the SQLITE_MUTEX_RECURSIVE mutex passed as the only argument as +** one on which there should be no contention. +*/ +void sqlite3MutexWarnOnContention(sqlite3_mutex *p){ + if( sqlite3GlobalConfig.mutex.xMutexAlloc==checkMutexAlloc ){ + CheckMutex *pCheck = (CheckMutex*)p; + assert( pCheck->iType==SQLITE_MUTEX_RECURSIVE ); + pCheck->iType = SQLITE_MUTEX_WARNONCONTENTION; + } +} +#endif /* ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS */ + /* ** Initialize the mutex system. */ int sqlite3MutexInit(void){ int rc = SQLITE_OK; @@ -39,11 +226,15 @@ */ sqlite3_mutex_methods const *pFrom; sqlite3_mutex_methods *pTo = &sqlite3GlobalConfig.mutex; if( sqlite3GlobalConfig.bCoreMutex ){ +#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS + pFrom = multiThreadedCheckMutex(); +#else pFrom = sqlite3DefaultMutex(); +#endif }else{ pFrom = sqlite3NoopMutex(); } pTo->xMutexInit = pFrom->xMutexInit; pTo->xMutexEnd = pFrom->xMutexEnd; @@ -165,5 +356,6 @@ return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p); } #endif #endif /* !defined(SQLITE_MUTEX_OMIT) */ + Index: src/sqliteInt.h ================================================================== --- src/sqliteInt.h +++ src/sqliteInt.h @@ -3587,10 +3587,16 @@ int sqlite3LookasideUsed(sqlite3*,int*); /* Access to mutexes used by sqlite3_status() */ sqlite3_mutex *sqlite3Pcache1Mutex(void); sqlite3_mutex *sqlite3MallocMutex(void); + +#if defined(SQLITE_ENABLE_MULTITHREADED_CHECKS) && !defined(SQLITE_MUTEX_OMIT) +void sqlite3MutexWarnOnContention(sqlite3_mutex*); +#else +# define sqlite3MutexWarnOnContention(x) +#endif #ifndef SQLITE_OMIT_FLOATING_POINT int sqlite3IsNaN(double); #else # define sqlite3IsNaN(X) 0