diff options
Diffstat (limited to 'third_party/sqlite/src/src/mutex_unix.c')
| -rw-r--r-- | third_party/sqlite/src/src/mutex_unix.c | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/third_party/sqlite/src/src/mutex_unix.c b/third_party/sqlite/src/src/mutex_unix.c index dc57988..aa9a8cf 100644 --- a/third_party/sqlite/src/src/mutex_unix.c +++ b/third_party/sqlite/src/src/mutex_unix.c @@ -10,8 +10,6 @@ ** ************************************************************************* ** This file contains the C functions that implement mutexes for pthreads -** -** $Id: mutex_unix.c,v 1.16 2008/12/08 18:19:18 drh Exp $ */ #include "sqliteInt.h" @@ -26,23 +24,33 @@ #include <pthread.h> +/* +** The sqlite3_mutex.id, sqlite3_mutex.nRef, and sqlite3_mutex.owner fields +** are necessary under two condidtions: (1) Debug builds and (2) using +** home-grown mutexes. Encapsulate these conditions into a single #define. +*/ +#if defined(SQLITE_DEBUG) || defined(SQLITE_HOMEGROWN_RECURSIVE_MUTEX) +# define SQLITE_MUTEX_NREF 1 +#else +# define SQLITE_MUTEX_NREF 0 +#endif /* ** Each recursive mutex is an instance of the following structure. */ struct sqlite3_mutex { pthread_mutex_t mutex; /* Mutex controlling the lock */ +#if SQLITE_MUTEX_NREF int id; /* Mutex type */ - int nRef; /* Number of entrances */ - pthread_t owner; /* Thread that is within this mutex */ -#ifdef SQLITE_DEBUG + volatile int nRef; /* Number of entrances */ + volatile pthread_t owner; /* Thread that is within this mutex */ int trace; /* True to trace changes */ #endif }; -#ifdef SQLITE_DEBUG +#if SQLITE_MUTEX_NREF #define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0, 0 } #else -#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, 0, 0, (pthread_t)0 } +#define SQLITE3_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER } #endif /* @@ -91,7 +99,7 @@ static int pthreadMutexEnd(void){ return SQLITE_OK; } ** <li> SQLITE_MUTEX_STATIC_MEM2 ** <li> SQLITE_MUTEX_STATIC_PRNG ** <li> SQLITE_MUTEX_STATIC_LRU -** <li> SQLITE_MUTEX_STATIC_LRU2 +** <li> SQLITE_MUTEX_STATIC_PMEM ** </ul> ** ** The first two constants cause sqlite3_mutex_alloc() to create @@ -144,14 +152,18 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){ pthread_mutex_init(&p->mutex, &recursiveAttr); pthread_mutexattr_destroy(&recursiveAttr); #endif +#if SQLITE_MUTEX_NREF p->id = iType; +#endif } break; } case SQLITE_MUTEX_FAST: { p = sqlite3MallocZero( sizeof(*p) ); if( p ){ +#if SQLITE_MUTEX_NREF p->id = iType; +#endif pthread_mutex_init(&p->mutex, 0); } break; @@ -160,7 +172,9 @@ static sqlite3_mutex *pthreadMutexAlloc(int iType){ assert( iType-2 >= 0 ); assert( iType-2 < ArraySize(staticMutexes) ); p = &staticMutexes[iType-2]; +#if SQLITE_MUTEX_NREF p->id = iType; +#endif break; } } @@ -220,9 +234,12 @@ static void pthreadMutexEnter(sqlite3_mutex *p){ /* Use the built-in recursive mutexes if they are available. */ pthread_mutex_lock(&p->mutex); +#if SQLITE_MUTEX_NREF + assert( p->nRef>0 || p->owner==0 ); p->owner = pthread_self(); p->nRef++; #endif +#endif #ifdef SQLITE_DEBUG if( p->trace ){ @@ -263,8 +280,10 @@ static int pthreadMutexTry(sqlite3_mutex *p){ /* Use the built-in recursive mutexes if they are available. */ if( pthread_mutex_trylock(&p->mutex)==0 ){ +#if SQLITE_MUTEX_NREF p->owner = pthread_self(); p->nRef++; +#endif rc = SQLITE_OK; }else{ rc = SQLITE_BUSY; @@ -287,7 +306,10 @@ static int pthreadMutexTry(sqlite3_mutex *p){ */ static void pthreadMutexLeave(sqlite3_mutex *p){ assert( pthreadMutexHeld(p) ); +#if SQLITE_MUTEX_NREF p->nRef--; + if( p->nRef==0 ) p->owner = 0; +#endif assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE ); #ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX @@ -305,8 +327,8 @@ static void pthreadMutexLeave(sqlite3_mutex *p){ #endif } -sqlite3_mutex_methods *sqlite3DefaultMutex(void){ - static sqlite3_mutex_methods sMutex = { +sqlite3_mutex_methods const *sqlite3DefaultMutex(void){ + static const sqlite3_mutex_methods sMutex = { pthreadMutexInit, pthreadMutexEnd, pthreadMutexAlloc, |