diff options
Diffstat (limited to 'rwlock.c')
| -rw-r--r-- | rwlock.c | 540 |
1 files changed, 273 insertions, 267 deletions
@@ -95,21 +95,21 @@ pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr) if (rwlock == NULL) { - return EINVAL; + return EINVAL; } if (attr != NULL && *attr != NULL) { - result = EINVAL; /* Not supported */ - goto DONE; + result = EINVAL; /* Not supported */ + goto DONE; } rwl = (pthread_rwlock_t) calloc(1, sizeof(*rwl)); if (rwl == NULL) { - result = ENOMEM; - goto DONE; + result = ENOMEM; + goto DONE; } rwl->nSharedAccessCount = 0; @@ -119,19 +119,19 @@ pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr) result = pthread_mutex_init(&rwl->mtxExclusiveAccess, NULL); if (result != 0) { - goto FAIL0; + goto FAIL0; } result = pthread_mutex_init(&rwl->mtxSharedAccessCompleted, NULL); if (result != 0) { - goto FAIL1; + goto FAIL1; } result = pthread_cond_init(&rwl->cndSharedAccessCompleted, NULL); if (result != 0) { - goto FAIL2; + goto FAIL2; } rwl->nMagic = PTW32_RWLOCK_MAGIC; @@ -163,92 +163,92 @@ pthread_rwlock_destroy(pthread_rwlock_t *rwlock) if (rwlock == NULL || *rwlock == NULL) { - return EINVAL; + return EINVAL; } if (*rwlock != PTHREAD_RWLOCK_INITIALIZER) { - rwl = *rwlock; - - if (rwl->nMagic != PTW32_RWLOCK_MAGIC) - { - return EINVAL; - } - - if ((result = pthread_mutex_lock(&(rwl->mtxExclusiveAccess))) != 0) - { - return result; - } - - if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; - } - - /* - * Check whether any threads own/wait for the lock (wait for ex.access); - * report "BUSY" if so. - */ - if (rwl->nExclusiveAccessCount > 0 - || rwl->nSharedAccessCount > rwl->nCompletedSharedAccessCount) - { - result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted)); - result1 = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - result2 = EBUSY; - } - else - { - rwl->nMagic = 0; - - if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - pthread_mutex_unlock(&rwl->mtxExclusiveAccess); - return result; - } - - if ((result = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess))) != 0) - { - return result; - } - - *rwlock = NULL; /* Invalidate rwlock before anything else */ - result = pthread_cond_destroy(&(rwl->cndSharedAccessCompleted)); - result1 = pthread_mutex_destroy(&(rwl->mtxSharedAccessCompleted)); - result2 = pthread_mutex_destroy(&(rwl->mtxExclusiveAccess)); - (void) free(rwl); - } + rwl = *rwlock; + + if (rwl->nMagic != PTW32_RWLOCK_MAGIC) + { + return EINVAL; + } + + if ((result = pthread_mutex_lock(&(rwl->mtxExclusiveAccess))) != 0) + { + return result; + } + + if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; + } + + /* + * Check whether any threads own/wait for the lock (wait for ex.access); + * report "BUSY" if so. + */ + if (rwl->nExclusiveAccessCount > 0 + || rwl->nSharedAccessCount > rwl->nCompletedSharedAccessCount) + { + result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted)); + result1 = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + result2 = EBUSY; + } + else + { + rwl->nMagic = 0; + + if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + pthread_mutex_unlock(&rwl->mtxExclusiveAccess); + return result; + } + + if ((result = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess))) != 0) + { + return result; + } + + *rwlock = NULL; /* Invalidate rwlock before anything else */ + result = pthread_cond_destroy(&(rwl->cndSharedAccessCompleted)); + result1 = pthread_mutex_destroy(&(rwl->mtxSharedAccessCompleted)); + result2 = pthread_mutex_destroy(&(rwl->mtxExclusiveAccess)); + (void) free(rwl); + } } else { - /* - * See notes in ptw32_rwlock_check_need_init() above also. - */ - EnterCriticalSection(&ptw32_rwlock_test_init_lock); - - /* - * Check again. - */ - if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) - { - /* - * This is all we need to do to destroy a statically - * initialised rwlock that has not yet been used (initialised). - * If we get to here, another thread - * waiting to initialise this rwlock will get an EINVAL. - */ - *rwlock = NULL; - } - else - { - /* - * The rwlock has been initialised while we were waiting - * so assume it's in use. - */ - result = EBUSY; - } - - LeaveCriticalSection(&ptw32_rwlock_test_init_lock); + /* + * See notes in ptw32_rwlock_check_need_init() above also. + */ + EnterCriticalSection(&ptw32_rwlock_test_init_lock); + + /* + * Check again. + */ + if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) + { + /* + * This is all we need to do to destroy a statically + * initialised rwlock that has not yet been used (initialised). + * If we get to here, another thread + * waiting to initialise this rwlock will get an EINVAL. + */ + *rwlock = NULL; + } + else + { + /* + * The rwlock has been initialised while we were waiting + * so assume it's in use. + */ + result = EBUSY; + } + + LeaveCriticalSection(&ptw32_rwlock_test_init_lock); } return ((result != 0) ? result : ((result1 != 0) ? result1 : result2)); @@ -265,7 +265,7 @@ pthread_rwlockattr_init (pthread_rwlockattr_t * attr) * * PARAMETERS * attr - * pointer to an instance of pthread_rwlockattr_t + * pointer to an instance of pthread_rwlockattr_t * * * DESCRIPTION @@ -273,8 +273,8 @@ pthread_rwlockattr_init (pthread_rwlockattr_t * attr) * attributes. * * RESULTS - * 0 successfully initialized attr, - * ENOMEM insufficient memory for attr. + * 0 successfully initialized attr, + * ENOMEM insufficient memory for attr. * * ------------------------------------------------------ */ @@ -296,7 +296,7 @@ pthread_rwlockattr_init (pthread_rwlockattr_t * attr) *attr = rwa; return(result); -} /* pthread_rwlockattr_init */ +} /* pthread_rwlockattr_init */ int @@ -309,7 +309,7 @@ pthread_rwlockattr_destroy (pthread_rwlockattr_t * attr) * * PARAMETERS * attr - * pointer to an instance of pthread_rwlockattr_t + * pointer to an instance of pthread_rwlockattr_t * * * DESCRIPTION @@ -317,11 +317,11 @@ pthread_rwlockattr_destroy (pthread_rwlockattr_t * attr) * no longer be used. * * NOTES: - * 1) Does not affect rwlockss created using 'attr' + * 1) Does not affect rwlockss created using 'attr' * * RESULTS - * 0 successfully released attr, - * EINVAL 'attr' is invalid. + * 0 successfully released attr, + * EINVAL 'attr' is invalid. * * ------------------------------------------------------ */ @@ -341,12 +341,12 @@ pthread_rwlockattr_destroy (pthread_rwlockattr_t * attr) } return(result); -} /* pthread_rwlockattr_destroy */ +} /* pthread_rwlockattr_destroy */ int pthread_rwlockattr_getpshared (const pthread_rwlockattr_t * attr, - int *pshared) + int *pshared) /* * ------------------------------------------------------ * DOCPUBLIC @@ -355,16 +355,16 @@ pthread_rwlockattr_getpshared (const pthread_rwlockattr_t * attr, * * PARAMETERS * attr - * pointer to an instance of pthread_rwlockattr_t + * pointer to an instance of pthread_rwlockattr_t * * pshared - * will be set to one of: + * will be set to one of: * - * PTHREAD_PROCESS_SHARED - * May be shared if in shared memory + * PTHREAD_PROCESS_SHARED + * May be shared if in shared memory * - * PTHREAD_PROCESS_PRIVATE - * Cannot be shared. + * PTHREAD_PROCESS_PRIVATE + * Cannot be shared. * * * DESCRIPTION @@ -372,15 +372,15 @@ pthread_rwlockattr_getpshared (const pthread_rwlockattr_t * attr, * processes if pthread_rwlock_t variable is allocated * in memory shared by these processes. * NOTES: - * 1) pshared rwlocks MUST be allocated in shared - * memory. - * 2) The following macro is defined if shared rwlocks - * are supported: - * _POSIX_THREAD_PROCESS_SHARED + * 1) pshared rwlocks MUST be allocated in shared + * memory. + * 2) The following macro is defined if shared rwlocks + * are supported: + * _POSIX_THREAD_PROCESS_SHARED * * RESULTS - * 0 successfully retrieved attribute, - * EINVAL 'attr' is invalid, + * 0 successfully retrieved attribute, + * EINVAL 'attr' is invalid, * * ------------------------------------------------------ */ @@ -400,7 +400,7 @@ pthread_rwlockattr_getpshared (const pthread_rwlockattr_t * attr, return (result); -} /* pthread_rwlockattr_getpshared */ +} /* pthread_rwlockattr_getpshared */ int @@ -415,16 +415,16 @@ pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, * * PARAMETERS * attr - * pointer to an instance of pthread_rwlockattr_t + * pointer to an instance of pthread_rwlockattr_t * * pshared - * must be one of: + * must be one of: * - * PTHREAD_PROCESS_SHARED - * May be shared if in shared memory + * PTHREAD_PROCESS_SHARED + * May be shared if in shared memory * - * PTHREAD_PROCESS_PRIVATE - * Cannot be shared. + * PTHREAD_PROCESS_PRIVATE + * Cannot be shared. * * DESCRIPTION * Rwlocks creatd with 'attr' can be shared between @@ -432,17 +432,17 @@ pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, * in memory shared by these processes. * * NOTES: - * 1) pshared rwlocks MUST be allocated in shared - * memory. + * 1) pshared rwlocks MUST be allocated in shared + * memory. * - * 2) The following macro is defined if shared rwlocks - * are supported: - * _POSIX_THREAD_PROCESS_SHARED + * 2) The following macro is defined if shared rwlocks + * are supported: + * _POSIX_THREAD_PROCESS_SHARED * * RESULTS - * 0 successfully set attribute, - * EINVAL 'attr' or pshared is invalid, - * ENOSYS PTHREAD_PROCESS_SHARED not supported, + * 0 successfully set attribute, + * EINVAL 'attr' or pshared is invalid, + * ENOSYS PTHREAD_PROCESS_SHARED not supported, * * ------------------------------------------------------ */ @@ -454,24 +454,24 @@ pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, (pshared == PTHREAD_PROCESS_PRIVATE))) { if (pshared == PTHREAD_PROCESS_SHARED) - { + { #if !defined( _POSIX_THREAD_PROCESS_SHARED ) - result = ENOSYS; - pshared = PTHREAD_PROCESS_PRIVATE; + result = ENOSYS; + pshared = PTHREAD_PROCESS_PRIVATE; #else - result = 0; + result = 0; #endif /* _POSIX_THREAD_PROCESS_SHARED */ - } + } else - { - result = 0; - } + { + result = 0; + } (*attr)->pshared = pshared; } @@ -482,7 +482,7 @@ pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, return (result); -} /* pthread_rwlockattr_setpshared */ +} /* pthread_rwlockattr_setpshared */ int @@ -493,7 +493,7 @@ pthread_rwlock_rdlock(pthread_rwlock_t *rwlock) if (rwlock == NULL || *rwlock == NULL) { - return EINVAL; + return EINVAL; } /* @@ -504,42 +504,42 @@ pthread_rwlock_rdlock(pthread_rwlock_t *rwlock) */ if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) { - result = ptw32_rwlock_check_need_init(rwlock); + result = ptw32_rwlock_check_need_init(rwlock); - if (result != 0 && result != EBUSY) - { - return result; - } + if (result != 0 && result != EBUSY) + { + return result; + } } rwl = *rwlock; if (rwl->nMagic != PTW32_RWLOCK_MAGIC) { - return EINVAL; + return EINVAL; } if ((result = pthread_mutex_lock(&(rwl->mtxExclusiveAccess))) != 0) { - return result; + return result; } if (++rwl->nSharedAccessCount == INT_MAX) { - if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; - } + if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; + } - rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; - rwl->nCompletedSharedAccessCount = 0; + rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; + rwl->nCompletedSharedAccessCount = 0; - if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; - } + if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; + } } return (pthread_mutex_unlock(&(rwl->mtxExclusiveAccess))); @@ -565,7 +565,7 @@ pthread_rwlock_wrlock(pthread_rwlock_t * rwlock) if (rwlock == NULL || *rwlock == NULL) { - return EINVAL; + return EINVAL; } /* @@ -576,69 +576,75 @@ pthread_rwlock_wrlock(pthread_rwlock_t * rwlock) */ if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) { - result = ptw32_rwlock_check_need_init(rwlock); + result = ptw32_rwlock_check_need_init(rwlock); - if (result != 0 && result != EBUSY) - { - return result; - } + if (result != 0 && result != EBUSY) + { + return result; + } } rwl = *rwlock; if (rwl->nMagic != PTW32_RWLOCK_MAGIC) { - return EINVAL; + return EINVAL; } if ((result = pthread_mutex_lock(&(rwl->mtxExclusiveAccess))) != 0) { - return result; + return result; } if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; } if (rwl->nExclusiveAccessCount == 0) { - if (rwl->nCompletedSharedAccessCount > 0) - { - rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; - rwl->nCompletedSharedAccessCount = 0; - } - - if (rwl->nSharedAccessCount > 0) - { - rwl->nCompletedSharedAccessCount = -rwl->nSharedAccessCount; - - /* - * This routine may be a cancelation point - * according to POSIX 1003.1j section 18.1.2. - */ - pthread_cleanup_push(ptw32_rwlock_cancelwrwait, (void*)rwl); - - do - { - result = pthread_cond_wait(&(rwl->cndSharedAccessCompleted), - &(rwl->mtxSharedAccessCompleted)); - } - while (result == 0 && rwl->nCompletedSharedAccessCount < 0); - - pthread_cleanup_pop ((result != 0) ? 1 : 0); - - if (result == 0) - { - rwl->nSharedAccessCount = 0; - } - } + if (rwl->nCompletedSharedAccessCount > 0) + { + rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; + rwl->nCompletedSharedAccessCount = 0; + } + + if (rwl->nSharedAccessCount > 0) + { + rwl->nCompletedSharedAccessCount = -rwl->nSharedAccessCount; + + /* + * This routine may be a cancelation point + * according to POSIX 1003.1j section 18.1.2. + */ +#ifdef _MSC_VER +#pragma inline_depth(0) +#endif + pthread_cleanup_push(ptw32_rwlock_cancelwrwait, (void*)rwl); + + do + { + result = pthread_cond_wait(&(rwl->cndSharedAccessCompleted), + &(rwl->mtxSharedAccessCompleted)); + } + while (result == 0 && rwl->nCompletedSharedAccessCount < 0); + + pthread_cleanup_pop ((result != 0) ? 1 : 0); +#ifdef _MSC_VER +#pragma inline_depth(8) +#endif + + if (result == 0) + { + rwl->nSharedAccessCount = 0; + } + } } if (result == 0) { - rwl->nExclusiveAccessCount++; + rwl->nExclusiveAccessCount++; } return result; @@ -652,44 +658,44 @@ pthread_rwlock_unlock(pthread_rwlock_t * rwlock) if (rwlock == NULL || *rwlock == NULL) { - return(EINVAL); + return(EINVAL); } if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) { - /* - * Assume any race condition here is harmless. - */ - return 0; + /* + * Assume any race condition here is harmless. + */ + return 0; } rwl = *rwlock; if (rwl->nMagic != PTW32_RWLOCK_MAGIC) { - return EINVAL; + return EINVAL; } if (rwl->nExclusiveAccessCount == 0) { - if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - return result; - } + if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + return result; + } - if (++rwl->nCompletedSharedAccessCount == 0) - { - result = pthread_cond_signal(&(rwl->cndSharedAccessCompleted)); - } + if (++rwl->nCompletedSharedAccessCount == 0) + { + result = pthread_cond_signal(&(rwl->cndSharedAccessCompleted)); + } - result1 = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted)); + result1 = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted)); } else { - rwl->nExclusiveAccessCount--; + rwl->nExclusiveAccessCount--; - result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted)); - result1 = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted)); + result1 = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); } @@ -704,7 +710,7 @@ pthread_rwlock_tryrdlock(pthread_rwlock_t * rwlock) if (rwlock == NULL || *rwlock == NULL) { - return EINVAL; + return EINVAL; } /* @@ -715,42 +721,42 @@ pthread_rwlock_tryrdlock(pthread_rwlock_t * rwlock) */ if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) { - result = ptw32_rwlock_check_need_init(rwlock); + result = ptw32_rwlock_check_need_init(rwlock); - if (result != 0 && result != EBUSY) - { - return result; - } + if (result != 0 && result != EBUSY) + { + return result; + } } rwl = *rwlock; if (rwl->nMagic != PTW32_RWLOCK_MAGIC) { - return EINVAL; + return EINVAL; } if ((result = pthread_mutex_trylock(&(rwl->mtxExclusiveAccess))) != 0) { - return result; + return result; } if (++rwl->nSharedAccessCount == INT_MAX) { - if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; - } + if ((result = pthread_mutex_lock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; + } - rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; - rwl->nCompletedSharedAccessCount = 0; + rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; + rwl->nCompletedSharedAccessCount = 0; - if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; - } + if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; + } } return (pthread_mutex_unlock(&rwl->mtxExclusiveAccess)); @@ -764,7 +770,7 @@ pthread_rwlock_trywrlock(pthread_rwlock_t * rwlock) if (rwlock == NULL || *rwlock == NULL) { - return EINVAL; + return EINVAL; } /* @@ -775,61 +781,61 @@ pthread_rwlock_trywrlock(pthread_rwlock_t * rwlock) */ if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) { - result = ptw32_rwlock_check_need_init(rwlock); + result = ptw32_rwlock_check_need_init(rwlock); - if (result != 0 && result != EBUSY) - { - return result; - } + if (result != 0 && result != EBUSY) + { + return result; + } } rwl = *rwlock; if (rwl->nMagic != PTW32_RWLOCK_MAGIC) { - return EINVAL; + return EINVAL; } if ((result = pthread_mutex_trylock(&(rwl->mtxExclusiveAccess))) != 0) { - return result; + return result; } if ((result = pthread_mutex_trylock(&(rwl->mtxSharedAccessCompleted))) != 0) { - result1 = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return ((result1 != 0) ? result1 : result); + result1 = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return ((result1 != 0) ? result1 : result); } if (rwl->nExclusiveAccessCount == 0) { - if (rwl->nCompletedSharedAccessCount > 0) - { - rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; - rwl->nCompletedSharedAccessCount = 0; - } - - if (rwl->nSharedAccessCount > 0) - { - if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) - { - (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); - return result; - } - - if ((result = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess))) == 0) - { - result = EBUSY; - } - } - else - { - rwl->nExclusiveAccessCount = 1; - } + if (rwl->nCompletedSharedAccessCount > 0) + { + rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; + rwl->nCompletedSharedAccessCount = 0; + } + + if (rwl->nSharedAccessCount > 0) + { + if ((result = pthread_mutex_unlock(&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock(&(rwl->mtxExclusiveAccess)); + return result; + } + + if ((result = pthread_mutex_unlock(&(rwl->mtxExclusiveAccess))) == 0) + { + result = EBUSY; + } + } + else + { + rwl->nExclusiveAccessCount = 1; + } } else { - result = EBUSY; + result = EBUSY; } return result; |