diff options
Diffstat (limited to 'mutex.c')
| -rw-r--r-- | mutex.c | 1080 |
1 files changed, 13 insertions, 1067 deletions
@@ -44,1073 +44,19 @@ #include "implement.h" -static INLINE int -ptw32_mutex_check_need_init(pthread_mutex_t *mutex) -{ - int result = 0; +#include "ptw32_mutex_check_need_init.c" +#include "pthread_mutex_init.c" +#include "pthread_mutex_destroy.c" +#include "pthread_mutexattr_init.c" +#include "pthread_mutexattr_destroy.c" +#include "pthread_mutexattr_getpshared.c" +#include "pthread_mutexattr_setpshared.c" +#include "pthread_mutexattr_settype.c" +#include "pthread_mutexattr_gettype.c" +#include "pthread_mutex_lock.c" +#include "pthread_mutex_timedlock.c" +#include "pthread_mutex_unlock.c" +#include "pthread_mutex_trylock.c" - /* - * The following guarded test is specifically for statically - * initialised mutexes (via PTHREAD_MUTEX_INITIALIZER). - * - * Note that by not providing this synchronisation we risk - * introducing race conditions into applications which are - * correctly written. - * - * Approach - * -------- - * We know that static mutexes will not be PROCESS_SHARED - * so we can serialise access to internal state using - * Win32 Critical Sections rather than Win32 Mutexes. - * - * If using a single global lock slows applications down too much, - * multiple global locks could be created and hashed on some random - * value associated with each mutex, the pointer perhaps. At a guess, - * a good value for the optimal number of global locks might be - * the number of processors + 1. - * - */ - EnterCriticalSection(&ptw32_mutex_test_init_lock); - - /* - * We got here possibly under race - * conditions. Check again inside the critical section - * and only initialise if the mutex is valid (not been destroyed). - * If a static mutex has been destroyed, the application can - * re-initialise it only by calling pthread_mutex_init() - * explicitly. - */ - if (*mutex == PTHREAD_MUTEX_INITIALIZER) - { - result = pthread_mutex_init(mutex, NULL); - } - else if (*mutex == NULL) - { - /* - * The mutex has been destroyed while we were waiting to - * initialise it, so the operation that caused the - * auto-initialisation should fail. - */ - result = EINVAL; - } - - LeaveCriticalSection(&ptw32_mutex_test_init_lock); - - return(result); -} - -int -pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr) -{ - int result = 0; - pthread_mutex_t mx; - - if (mutex == NULL) - { - return EINVAL; - } - - if (attr != NULL - && *attr != NULL - && (*attr)->pshared == PTHREAD_PROCESS_SHARED - ) - { - /* - * Creating mutex that can be shared between - * processes. - */ -#if _POSIX_THREAD_PROCESS_SHARED - - /* - * Not implemented yet. - */ - -#error ERROR [__FILE__, line __LINE__]: Process shared mutexes are not supported yet. - -#else - - return ENOSYS; - -#endif /* _POSIX_THREAD_PROCESS_SHARED */ - - } - - mx = (pthread_mutex_t) calloc(1, sizeof(*mx)); - - if (mx == NULL) - { - result = ENOMEM; - } - else - { - mx->lock_idx = PTW32_MUTEX_LOCK_IDX_INIT; - mx->recursive_count = 0; - mx->kind = (attr == NULL || *attr == NULL - ? PTHREAD_MUTEX_DEFAULT - : (*attr)->kind); - mx->ownerThread = NULL; - - if ( 0 != sem_init( &mx->wait_sema, 0, 0 )) - { - result = EAGAIN; - free(mx); - mx = NULL; - } - else - { - InitializeCriticalSection( &mx->wait_cs ); - } - } - - *mutex = mx; - - return(result); -} - -int -pthread_mutex_destroy(pthread_mutex_t *mutex) -{ - int result = 0; - pthread_mutex_t mx; - - if (mutex == NULL - || *mutex == NULL) - { - return EINVAL; - } - - /* - * Check to see if we have something to delete. - */ - if (*mutex != PTHREAD_MUTEX_INITIALIZER) - { - mx = *mutex; - - result = pthread_mutex_trylock(&mx); - - /* - * The mutex type may not be RECURSIVE therefore trylock may return EBUSY if - * we already own the mutex. Here we are assuming that it's OK to destroy - * a mutex that we own and have locked recursively. Is this correct? - * - * For FAST mutexes we record the owner as ANONYMOUS for speed. In this - * case we assume that the thread calling pthread_mutex_destroy() is the - * owner, if the mutex is owned at all. - */ - if (result == 0 - || mx->ownerThread == (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS - || pthread_equal( mx->ownerThread, pthread_self() ) ) - { - /* - * FIXME!!! - * The mutex isn't held by another thread but we could still - * be too late invalidating the mutex below since another thread - * may already have entered mutex_lock and the check for a valid - * *mutex != NULL. - */ - *mutex = NULL; - - result = pthread_mutex_unlock(&mx); - - if (result == 0) - { - (void) sem_destroy( &mx->wait_sema ); - DeleteCriticalSection( &mx->wait_cs ); - free(mx); - } - else - { - /* - * Restore the mutex before we return the error. - */ - *mutex = mx; - } - } - } - else - { - /* - * See notes in ptw32_mutex_check_need_init() above also. - */ - EnterCriticalSection(&ptw32_mutex_test_init_lock); - - /* - * Check again. - */ - if (*mutex == PTHREAD_MUTEX_INITIALIZER) - { - /* - * This is all we need to do to destroy a statically - * initialised mutex that has not yet been used (initialised). - * If we get to here, another thread - * waiting to initialise this mutex will get an EINVAL. - */ - *mutex = NULL; - } - else - { - /* - * The mutex has been initialised while we were waiting - * so assume it's in use. - */ - result = EBUSY; - } - - LeaveCriticalSection(&ptw32_mutex_test_init_lock); - } - - return(result); -} - -int -pthread_mutexattr_init (pthread_mutexattr_t * attr) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * Initializes a mutex attributes object with default - * attributes. - * - * PARAMETERS - * attr - * pointer to an instance of pthread_mutexattr_t - * - * - * DESCRIPTION - * Initializes a mutex attributes object with default - * attributes. - * - * NOTES: - * 1) Used to define mutex types - * - * RESULTS - * 0 successfully initialized attr, - * ENOMEM insufficient memory for attr. - * - * ------------------------------------------------------ - */ -{ - int result = 0; - pthread_mutexattr_t ma; - - ma = (pthread_mutexattr_t) calloc (1, sizeof (*ma)); - - if (ma == NULL) - { - result = ENOMEM; - } - else - { - ma->pshared = PTHREAD_PROCESS_PRIVATE; - ma->kind = PTHREAD_MUTEX_DEFAULT; - } - - *attr = ma; - - return(result); -} /* pthread_mutexattr_init */ - - -int -pthread_mutexattr_destroy (pthread_mutexattr_t * attr) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * Destroys a mutex attributes object. The object can - * no longer be used. - * - * PARAMETERS - * attr - * pointer to an instance of pthread_mutexattr_t - * - * - * DESCRIPTION - * Destroys a mutex attributes object. The object can - * no longer be used. - * - * NOTES: - * 1) Does not affect mutexes created using 'attr' - * - * RESULTS - * 0 successfully released attr, - * EINVAL 'attr' is invalid. - * - * ------------------------------------------------------ - */ -{ - int result = 0; - - if (attr == NULL || *attr == NULL) - { - result = EINVAL; - } - else - { - pthread_mutexattr_t ma = *attr; - - *attr = NULL; - free (ma); - } - - return(result); -} /* pthread_mutexattr_destroy */ - - -int -pthread_mutexattr_getpshared (const pthread_mutexattr_t * attr, - int *pshared) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * Determine whether mutexes created with 'attr' can be - * shared between processes. - * - * PARAMETERS - * attr - * pointer to an instance of pthread_mutexattr_t - * - * pshared - * will be set to one of: - * - * PTHREAD_PROCESS_SHARED - * May be shared if in shared memory - * - * PTHREAD_PROCESS_PRIVATE - * Cannot be shared. - * - * - * DESCRIPTION - * Mutexes creatd with 'attr' can be shared between - * processes if pthread_mutex_t variable is allocated - * in memory shared by these processes. - * NOTES: - * 1) pshared mutexes MUST be allocated in shared - * memory. - * 2) The following macro is defined if shared mutexes - * are supported: - * _POSIX_THREAD_PROCESS_SHARED - * - * RESULTS - * 0 successfully retrieved attribute, - * EINVAL 'attr' is invalid, - * - * ------------------------------------------------------ - */ -{ - int result; - - if ((attr != NULL && *attr != NULL) && - (pshared != NULL)) - { - *pshared = (*attr)->pshared; - result = 0; - } - else - { - result = EINVAL; - } - - return (result); - -} /* pthread_mutexattr_getpshared */ - - -int -pthread_mutexattr_setpshared (pthread_mutexattr_t * attr, - int pshared) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * Mutexes created with 'attr' can be shared between - * processes if pthread_mutex_t variable is allocated - * in memory shared by these processes. - * - * PARAMETERS - * attr - * pointer to an instance of pthread_mutexattr_t - * - * pshared - * must be one of: - * - * PTHREAD_PROCESS_SHARED - * May be shared if in shared memory - * - * PTHREAD_PROCESS_PRIVATE - * Cannot be shared. - * - * DESCRIPTION - * Mutexes creatd with 'attr' can be shared between - * processes if pthread_mutex_t variable is allocated - * in memory shared by these processes. - * - * NOTES: - * 1) pshared mutexes MUST be allocated in shared - * memory. - * - * 2) The following macro is defined if shared mutexes - * are supported: - * _POSIX_THREAD_PROCESS_SHARED - * - * RESULTS - * 0 successfully set attribute, - * EINVAL 'attr' or pshared is invalid, - * ENOSYS PTHREAD_PROCESS_SHARED not supported, - * - * ------------------------------------------------------ - */ -{ - int result; - - if ((attr != NULL && *attr != NULL) && - ((pshared == PTHREAD_PROCESS_SHARED) || - (pshared == PTHREAD_PROCESS_PRIVATE))) - { - if (pshared == PTHREAD_PROCESS_SHARED) - { - -#if !defined( _POSIX_THREAD_PROCESS_SHARED ) - - result = ENOSYS; - pshared = PTHREAD_PROCESS_PRIVATE; - -#else - - result = 0; - -#endif /* _POSIX_THREAD_PROCESS_SHARED */ - - } - else - { - result = 0; - } - - (*attr)->pshared = pshared; - } - else - { - result = EINVAL; - } - - return (result); - -} /* pthread_mutexattr_setpshared */ - - -int -pthread_mutexattr_settype (pthread_mutexattr_t * attr, - int kind) - /* - * ------------------------------------------------------ - * - * DOCPUBLIC - * The pthread_mutexattr_settype() and - * pthread_mutexattr_gettype() functions respectively set and - * get the mutex type attribute. This attribute is set in the - * type parameter to these functions. - * - * PARAMETERS - * attr - * pointer to an instance of pthread_mutexattr_t - * - * type - * must be one of: - * - * PTHREAD_MUTEX_DEFAULT - * - * PTHREAD_MUTEX_NORMAL - * - * PTHREAD_MUTEX_ERRORCHECK - * - * PTHREAD_MUTEX_RECURSIVE - * - * DESCRIPTION - * The pthread_mutexattr_settype() and - * pthread_mutexattr_gettype() functions respectively set and - * get the mutex type attribute. This attribute is set in the - * type parameter to these functions. The default value of the - * type attribute is PTHREAD_MUTEX_DEFAULT. - * - * The type of mutex is contained in the type attribute of the - * mutex attributes. Valid mutex types include: - * - * PTHREAD_MUTEX_NORMAL - * This type of mutex does not detect deadlock. A - * thread attempting to relock this mutex without - * first unlocking it will deadlock. Attempting to - * unlock a mutex locked by a different thread - * results in undefined behavior. Attempting to - * unlock an unlocked mutex results in undefined - * behavior. - * - * PTHREAD_MUTEX_ERRORCHECK - * This type of mutex provides error checking. A - * thread attempting to relock this mutex without - * first unlocking it will return with an error. A - * thread attempting to unlock a mutex which another - * thread has locked will return with an error. A - * thread attempting to unlock an unlocked mutex will - * return with an error. - * - * PTHREAD_MUTEX_DEFAULT - * Same as PTHREAD_MUTEX_NORMAL. - * - * PTHREAD_MUTEX_RECURSIVE - * A thread attempting to relock this mutex without - * first unlocking it will succeed in locking the - * mutex. The relocking deadlock which can occur with - * mutexes of type PTHREAD_MUTEX_NORMAL cannot occur - * with this type of mutex. Multiple locks of this - * mutex require the same number of unlocks to - * release the mutex before another thread can - * acquire the mutex. A thread attempting to unlock a - * mutex which another thread has locked will return - * with an error. A thread attempting to unlock an - * unlocked mutex will return with an error. This - * type of mutex is only supported for mutexes whose - * process shared attribute is - * PTHREAD_PROCESS_PRIVATE. - * - * RESULTS - * 0 successfully set attribute, - * EINVAL 'attr' or 'type' is invalid, - * - * ------------------------------------------------------ - */ -{ - int result = 0; - - if ((attr != NULL && *attr != NULL)) - { - switch (kind) - { - case PTHREAD_MUTEX_FAST_NP: - case PTHREAD_MUTEX_RECURSIVE_NP: - case PTHREAD_MUTEX_ERRORCHECK_NP: - (*attr)->kind = kind; - break; - default: - result = EINVAL; - break; - } - } - else - { - result = EINVAL; - } - - return (result); -} /* pthread_mutexattr_settype */ - - -int -pthread_mutexattr_gettype (pthread_mutexattr_t * attr, - int *kind) -{ - int result = 0; - - if (attr != NULL && *attr != NULL && kind != NULL) - { - *kind = (*attr)->kind; - } - else - { - result = EINVAL; - } - - return (result); -} - - -static INLINE int -ptw32_timed_semwait (sem_t * sem, const struct timespec * abstime) - /* - * ------------------------------------------------------ - * DESCRIPTION - * This function waits on a POSIX semaphore. If the - * semaphore value is greater than zero, it decreases - * its value by one. If the semaphore value is zero, then - * the calling thread (or process) is blocked until it can - * successfully decrease the value or until abstime. - * If abstime has passed when this routine is called then - * it returns a result to indicate this. - * - * If 'abstime' is a NULL pointer then this function will - * block until it can successfully decrease the value or - * until interrupted by a signal. - * - * RESULTS - * 2 abstime has passed already - * 1 abstime timed out while waiting - * 0 successfully decreased semaphore, - * -1 failed, error in errno. - * ERRNO - * EINVAL 'sem' is not a valid semaphore, - * ENOSYS semaphores are not supported, - * EINTR the function was interrupted by a signal, - * EDEADLK a deadlock condition was detected. - * - * ------------------------------------------------------ - */ -{ - int result = 0; - -#ifdef NEED_FTIME - - struct timespec currSysTime; - -#else /* NEED_FTIME */ - - struct _timeb currSysTime; - -#endif /* NEED_FTIME */ - - const DWORD NANOSEC_PER_MILLISEC = 1000000; - const DWORD MILLISEC_PER_SEC = 1000; - DWORD milliseconds; - DWORD status; - - if (sem == NULL) - { - result = EINVAL; - } - else - { - if (abstime == NULL) - { - milliseconds = INFINITE; - } - else - { - /* - * Calculate timeout as milliseconds from current system time. - */ - - /* get current system time */ - -#ifdef NEED_FTIME - - { - FILETIME ft; - SYSTEMTIME st; - - GetSystemTime(&st); - SystemTimeToFileTime(&st, &ft); - /* - * GetSystemTimeAsFileTime(&ft); would be faster, - * but it does not exist on WinCE - */ - - filetime_to_timespec(&ft, &currSysTime); - } - - /* - * subtract current system time from abstime - */ - milliseconds = (abstime->tv_sec - currSysTime.tv_sec) * MILLISEC_PER_SEC; - milliseconds += ((abstime->tv_nsec - currSysTime.tv_nsec) + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC; - -#else /* NEED_FTIME */ - _ftime(&currSysTime); - - /* - * subtract current system time from abstime - */ - milliseconds = (abstime->tv_sec - currSysTime.time) * MILLISEC_PER_SEC; - milliseconds += ((abstime->tv_nsec + (NANOSEC_PER_MILLISEC/2)) / NANOSEC_PER_MILLISEC) - - currSysTime.millitm; - -#endif /* NEED_FTIME */ - - - if (((int) milliseconds) < 0) - { - return 2; - } - } - -#ifdef NEED_SEM - - status = WaitForSingleObject( (*sem)->event, milliseconds ); - -#else /* NEED_SEM */ - - status = WaitForSingleObject( (*sem)->sem, milliseconds ); - -#endif - - if (status == WAIT_OBJECT_0) - { - -#ifdef NEED_SEM - - ptw32_decrease_semaphore(sem); - -#endif /* NEED_SEM */ - - return 0; - } - else if (status == WAIT_TIMEOUT) - { - return 1; - } - else - { - result = EINVAL; - } - } - - if (result != 0) - { - errno = result; - return -1; - } - - return 0; - -} /* ptw32_timed_semwait */ - - -int -pthread_mutex_lock(pthread_mutex_t *mutex) -{ - int result = 0; - pthread_mutex_t mx; - - - if (mutex == NULL || *mutex == NULL) - { - return EINVAL; - } - - /* - * We do a quick check to see if we need to do more work - * to initialise a static mutex. We check - * again inside the guarded section of ptw32_mutex_check_need_init() - * to avoid race conditions. - */ - if (*mutex == PTHREAD_MUTEX_INITIALIZER) - { - if ((result = ptw32_mutex_check_need_init(mutex)) != 0) - { - return(result); - } - } - - mx = *mutex; - - if( 0 == InterlockedIncrement( &mx->lock_idx ) ) - { - mx->recursive_count = 1; - mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); - } - else - { - if( mx->kind != PTHREAD_MUTEX_FAST_NP && - pthread_equal( mx->ownerThread, pthread_self() ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - - if( mx->kind == PTHREAD_MUTEX_RECURSIVE_NP ) - { - mx->recursive_count++; - } - else - { - result = EDEADLK; - } - } - else - { - if ((result = sem_wait( &mx->wait_sema )) == 0) - { - mx->recursive_count = 1; - mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); - } - } - } - - return(result); -} - - -int -pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime) -{ - int result = 0; - pthread_mutex_t mx; - -#ifdef NEED_SEM - errno = ENOTSUP; - return -1; -#endif - - if (mutex == NULL || *mutex == NULL) - { - return EINVAL; - } - - /* - * We do a quick check to see if we need to do more work - * to initialise a static mutex. We check - * again inside the guarded section of ptw32_mutex_check_need_init() - * to avoid race conditions. - */ - if (*mutex == PTHREAD_MUTEX_INITIALIZER) - { - if ((result = ptw32_mutex_check_need_init(mutex)) != 0) - { - return(result); - } - } - - mx = *mutex; - - if( 0 == InterlockedIncrement( &mx->lock_idx ) ) - { - mx->recursive_count = 1; - mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); - } - else - { - if( mx->kind != PTHREAD_MUTEX_FAST_NP && - pthread_equal( mx->ownerThread, pthread_self() ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - - if( mx->kind == PTHREAD_MUTEX_RECURSIVE_NP ) - { - mx->recursive_count++; - } - else - { - result = EDEADLK; - } - } - else - { - if (abstime == NULL) - { - result = EINVAL; - } - else - { - switch (ptw32_timed_semwait( &mx->wait_sema, abstime )) - { - case 0: /* We got the mutex. */ - { - mx->recursive_count = 1; - mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); - break; - } - case 1: /* Timedout, try a second grab. */ - { - EnterCriticalSection(&mx->wait_cs); - - /* - * If we timeout, it is up to us to adjust lock_idx to say - * we're no longer waiting. If the mutex was also unlocked - * while we were timing out, and we simply return ETIMEDOUT, - * then wait_sema would be left in a state that is not consistent - * with the state of lock_idx. - * - * We must check to see if wait_sema has just been posted - * but we can't just call sem_getvalue - we must compete for - * the semaphore using sem_trywait(), otherwise we would need - * additional critical sections elsewhere, which would make the - * logic too inefficient. - * - * If sem_trywait returns EAGAIN then either wait_sema - * was given directly to another waiting thread or - * another thread has called sem_*wait() before us and - * taken the lock. Then we MUST decrement lock_idx and return - * ETIMEDOUT. - * - * Otherwise we MUST return success (because we have effectively - * acquired the lock that would have been ours had we not - * timed out), and NOT decrement lock_idx. - * - * We can almost guarrantee that EAGAIN is the only - * possible error, so no need to test errno. - */ - - if ( -1 == sem_trywait( &mx->wait_sema ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - result = ETIMEDOUT; - } - - LeaveCriticalSection(&mx->wait_cs); - break; - } - case 2: /* abstime passed before we started to wait. */ - { - /* - * If we timeout, it is up to us to adjust lock_idx to say - * we're no longer waiting. - * - * The owner thread may still have posted wait_sema thinking - * we were waiting. I believe we must check but then NOT do any - * programmed work if we have acquired the mutex because - * we don't how long ago abstime was. We MUST just release it - * immediately. - */ - EnterCriticalSection(&mx->wait_cs); - - result = ETIMEDOUT; - - if ( -1 == sem_trywait( &mx->wait_sema ) ) - { - (void) InterlockedDecrement( &mx->lock_idx ); - } - else - { - if ( InterlockedDecrement( &mx->lock_idx ) >= 0 ) - { - /* Someone else is waiting on that mutex */ - if ( sem_post( &mx->wait_sema ) != 0 ) - { - result = errno; - } - } - } - - LeaveCriticalSection(&mx->wait_cs); - break; - } - default: - { - result = errno; - break; - } - } - } - } - } - - return(result); -} - - -int -pthread_mutex_unlock(pthread_mutex_t *mutex) -{ - int result = 0; - pthread_mutex_t mx; - - if (mutex == NULL || *mutex == NULL) - { - return EINVAL; - } - - mx = *mutex; - - /* - * If the thread calling us holds the mutex then there is no - * race condition. If another thread holds the - * lock then we shouldn't be in here. - */ - if (mx != PTHREAD_MUTEX_INITIALIZER) - { - if (mx->ownerThread == (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS - || pthread_equal(mx->ownerThread, pthread_self())) - { - if( mx->kind != PTHREAD_MUTEX_RECURSIVE_NP - || 0 == --mx->recursive_count ) - { - mx->ownerThread = NULL; - EnterCriticalSection( &mx->wait_cs ); - - if( InterlockedDecrement( &mx->lock_idx ) >= 0 ) - { - /* Someone is waiting on that mutex */ - if (sem_post( &mx->wait_sema ) != 0) - { - result = errno; - } - } - - LeaveCriticalSection( &mx->wait_cs ); - } - } - else - { - result = EPERM; - } - } - else - { - result = EINVAL; - } - - return(result); -} - -int -pthread_mutex_trylock(pthread_mutex_t *mutex) -{ - int result = 0; - pthread_mutex_t mx; - - if (mutex == NULL || *mutex == NULL) - { - return EINVAL; - } - - /* - * We do a quick check to see if we need to do more work - * to initialise a static mutex. We check - * again inside the guarded section of ptw32_mutex_check_need_init() - * to avoid race conditions. - */ - if (*mutex == PTHREAD_MUTEX_INITIALIZER) - { - result = ptw32_mutex_check_need_init(mutex); - } - - mx = *mutex; - - if (result == 0) - { - if ( (PTW32_INTERLOCKED_LONG) PTW32_MUTEX_LOCK_IDX_INIT == - ptw32_interlocked_compare_exchange((PTW32_INTERLOCKED_LPLONG) &mx->lock_idx, - (PTW32_INTERLOCKED_LONG) 0, - (PTW32_INTERLOCKED_LONG) PTW32_MUTEX_LOCK_IDX_INIT)) - { - mx->recursive_count = 1; - mx->ownerThread = (mx->kind != PTHREAD_MUTEX_FAST_NP - ? pthread_self() - : (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS); - } - else - { - if( mx->kind != PTHREAD_MUTEX_FAST_NP && - pthread_equal( mx->ownerThread, pthread_self() ) ) - { - if( mx->kind == PTHREAD_MUTEX_RECURSIVE_NP ) - { - mx->recursive_count++; - } - else - { - result = EDEADLK; - } - } - else - { - result = EBUSY; - } - } - } - - return(result); -} |