diff options
Diffstat (limited to 'nsprpub/pr/src/pthreads/ptsynch.c')
| -rw-r--r-- | nsprpub/pr/src/pthreads/ptsynch.c | 1295 |
1 files changed, 1295 insertions, 0 deletions
diff --git a/nsprpub/pr/src/pthreads/ptsynch.c b/nsprpub/pr/src/pthreads/ptsynch.c new file mode 100644 index 0000000000..26f58b2d0f --- /dev/null +++ b/nsprpub/pr/src/pthreads/ptsynch.c @@ -0,0 +1,1295 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* +** File: ptsynch.c +** Descritpion: Implemenation for thread synchronization using pthreads +** Exports: prlock.h, prcvar.h, prmon.h, prcmon.h +*/ + +#if defined(_PR_PTHREADS) + +#include "primpl.h" +#include "obsolete/prsem.h" + +#include <string.h> +#include <pthread.h> +#include <sys/time.h> + +static pthread_mutexattr_t _pt_mattr; +static pthread_condattr_t _pt_cvar_attr; + +#if defined(DEBUG) +extern PTDebug pt_debug; /* this is shared between several modules */ +#endif /* defined(DEBUG) */ + +#if defined(FREEBSD) +/* + * On older versions of FreeBSD, pthread_mutex_trylock returns EDEADLK. + * Newer versions return EBUSY. We still need to support both. + */ +static int +pt_pthread_mutex_is_locked(pthread_mutex_t *m) +{ + int rv = pthread_mutex_trylock(m); + return (EBUSY == rv || EDEADLK == rv); +} +#endif + +/**************************************************************/ +/**************************************************************/ +/*****************************LOCKS****************************/ +/**************************************************************/ +/**************************************************************/ + +void _PR_InitLocks(void) +{ + int rv; + rv = _PT_PTHREAD_MUTEXATTR_INIT(&_pt_mattr); + PR_ASSERT(0 == rv); + +#if (defined(LINUX) && (__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 2)) || \ + (defined(FREEBSD) && __FreeBSD_version > 700055) + rv = pthread_mutexattr_settype(&_pt_mattr, PTHREAD_MUTEX_ADAPTIVE_NP); + PR_ASSERT(0 == rv); +#endif + + rv = _PT_PTHREAD_CONDATTR_INIT(&_pt_cvar_attr); + PR_ASSERT(0 == rv); +} + +static void pt_PostNotifies(PRLock *lock, PRBool unlock) +{ + PRIntn index, rv; + _PT_Notified post; + _PT_Notified *notified, *prev = NULL; + /* + * Time to actually notify any conditions that were affected + * while the lock was held. Get a copy of the list that's in + * the lock structure and then zero the original. If it's + * linked to other such structures, we own that storage. + */ + post = lock->notified; /* a safe copy; we own the lock */ + +#if defined(DEBUG) + memset(&lock->notified, 0, sizeof(_PT_Notified)); /* reset */ +#else + lock->notified.length = 0; /* these are really sufficient */ + lock->notified.link = NULL; +#endif + + /* should (may) we release lock before notifying? */ + if (unlock) + { + rv = pthread_mutex_unlock(&lock->mutex); + PR_ASSERT(0 == rv); + } + + notified = &post; /* this is where we start */ + do + { + for (index = 0; index < notified->length; ++index) + { + PRCondVar *cv = notified->cv[index].cv; + PR_ASSERT(NULL != cv); + PR_ASSERT(0 != notified->cv[index].times); + if (-1 == notified->cv[index].times) + { + rv = pthread_cond_broadcast(&cv->cv); + PR_ASSERT(0 == rv); + } + else + { + while (notified->cv[index].times-- > 0) + { + rv = pthread_cond_signal(&cv->cv); + PR_ASSERT(0 == rv); + } + } +#if defined(DEBUG) + pt_debug.cvars_notified += 1; + if (0 > PR_ATOMIC_DECREMENT(&cv->notify_pending)) + { + pt_debug.delayed_cv_deletes += 1; + PR_DestroyCondVar(cv); + } +#else /* defined(DEBUG) */ + if (0 > PR_ATOMIC_DECREMENT(&cv->notify_pending)) { + PR_DestroyCondVar(cv); + } +#endif /* defined(DEBUG) */ + } + prev = notified; + notified = notified->link; + if (&post != prev) { + PR_DELETE(prev); + } + } while (NULL != notified); +} /* pt_PostNotifies */ + +PR_IMPLEMENT(PRLock*) PR_NewLock(void) +{ + PRIntn rv; + PRLock *lock; + + if (!_pr_initialized) { + _PR_ImplicitInitialization(); + } + + lock = PR_NEWZAP(PRLock); + if (lock != NULL) + { + rv = _PT_PTHREAD_MUTEX_INIT(lock->mutex, _pt_mattr); + PR_ASSERT(0 == rv); + } +#if defined(DEBUG) + pt_debug.locks_created += 1; +#endif + return lock; +} /* PR_NewLock */ + +PR_IMPLEMENT(void) PR_DestroyLock(PRLock *lock) +{ + PRIntn rv; + PR_ASSERT(NULL != lock); + PR_ASSERT(PR_FALSE == lock->locked); + PR_ASSERT(0 == lock->notified.length); + PR_ASSERT(NULL == lock->notified.link); + rv = pthread_mutex_destroy(&lock->mutex); + PR_ASSERT(0 == rv); +#if defined(DEBUG) + memset(lock, 0xaf, sizeof(PRLock)); + pt_debug.locks_destroyed += 1; +#endif + PR_Free(lock); +} /* PR_DestroyLock */ + +PR_IMPLEMENT(void) PR_Lock(PRLock *lock) +{ + /* Nb: PR_Lock must not call PR_GetCurrentThread to access the |id| or + * |tid| field of the current thread's PRThread structure because + * _pt_root calls PR_Lock before setting thred->id and thred->tid. */ + PRIntn rv; + PR_ASSERT(lock != NULL); + rv = pthread_mutex_lock(&lock->mutex); + PR_ASSERT(0 == rv); + PR_ASSERT(0 == lock->notified.length); + PR_ASSERT(NULL == lock->notified.link); + PR_ASSERT(PR_FALSE == lock->locked); + /* Nb: the order of the next two statements is not critical to + * the correctness of PR_AssertCurrentThreadOwnsLock(), but + * this particular order makes the assertion more likely to + * catch errors. */ + lock->owner = pthread_self(); + lock->locked = PR_TRUE; +#if defined(DEBUG) + pt_debug.locks_acquired += 1; +#endif +} /* PR_Lock */ + +PR_IMPLEMENT(PRStatus) PR_Unlock(PRLock *lock) +{ + pthread_t self = pthread_self(); + PRIntn rv; + + PR_ASSERT(lock != NULL); + PR_ASSERT(_PT_PTHREAD_MUTEX_IS_LOCKED(lock->mutex)); + PR_ASSERT(PR_TRUE == lock->locked); + PR_ASSERT(pthread_equal(lock->owner, self)); + + if (!lock->locked || !pthread_equal(lock->owner, self)) { + return PR_FAILURE; + } + + lock->locked = PR_FALSE; + if (0 == lock->notified.length) /* shortcut */ + { + rv = pthread_mutex_unlock(&lock->mutex); + PR_ASSERT(0 == rv); + } + else { + pt_PostNotifies(lock, PR_TRUE); + } + +#if defined(DEBUG) + pt_debug.locks_released += 1; +#endif + return PR_SUCCESS; +} /* PR_Unlock */ + +PR_IMPLEMENT(void) PR_AssertCurrentThreadOwnsLock(PRLock *lock) +{ + /* Nb: the order of the |locked| and |owner==me| checks is not critical + * to the correctness of PR_AssertCurrentThreadOwnsLock(), but + * this particular order makes the assertion more likely to + * catch errors. */ + PR_ASSERT(lock->locked && pthread_equal(lock->owner, pthread_self())); +} + +/**************************************************************/ +/**************************************************************/ +/***************************CONDITIONS*************************/ +/**************************************************************/ +/**************************************************************/ + + +/* + * This code is used to compute the absolute time for the wakeup. + * It's moderately ugly, so it's defined here and called in a + * couple of places. + */ +#define PT_NANOPERMICRO 1000UL +#define PT_BILLION 1000000000UL + +static PRIntn pt_TimedWait( + pthread_cond_t *cv, pthread_mutex_t *ml, PRIntervalTime timeout) +{ + int rv; + struct timeval now; + struct timespec tmo; + PRUint32 ticks = PR_TicksPerSecond(); + + tmo.tv_sec = (PRInt32)(timeout / ticks); + tmo.tv_nsec = (PRInt32)(timeout - (tmo.tv_sec * ticks)); + tmo.tv_nsec = (PRInt32)PR_IntervalToMicroseconds(PT_NANOPERMICRO * tmo.tv_nsec); + + /* pthreads wants this in absolute time, off we go ... */ + (void)GETTIMEOFDAY(&now); + /* that one's usecs, this one's nsecs - grrrr! */ + tmo.tv_sec += now.tv_sec; + tmo.tv_nsec += (PT_NANOPERMICRO * now.tv_usec); + tmo.tv_sec += tmo.tv_nsec / PT_BILLION; + tmo.tv_nsec %= PT_BILLION; + + rv = pthread_cond_timedwait(cv, ml, &tmo); + + /* NSPR doesn't report timeouts */ + return (rv == ETIMEDOUT) ? 0 : rv; +} /* pt_TimedWait */ + + +/* + * Notifies just get posted to the protecting mutex. The + * actual notification is done when the lock is released so that + * MP systems don't contend for a lock that they can't have. + */ +static void pt_PostNotifyToCvar(PRCondVar *cvar, PRBool broadcast) +{ + PRIntn index = 0; + _PT_Notified *notified = &cvar->lock->notified; + + PR_ASSERT(PR_TRUE == cvar->lock->locked); + PR_ASSERT(pthread_equal(cvar->lock->owner, pthread_self())); + PR_ASSERT(_PT_PTHREAD_MUTEX_IS_LOCKED(cvar->lock->mutex)); + + while (1) + { + for (index = 0; index < notified->length; ++index) + { + if (notified->cv[index].cv == cvar) + { + if (broadcast) { + notified->cv[index].times = -1; + } + else if (-1 != notified->cv[index].times) { + notified->cv[index].times += 1; + } + return; /* we're finished */ + } + } + /* if not full, enter new CV in this array */ + if (notified->length < PT_CV_NOTIFIED_LENGTH) { + break; + } + + /* if there's no link, create an empty array and link it */ + if (NULL == notified->link) { + notified->link = PR_NEWZAP(_PT_Notified); + } + notified = notified->link; + } + + /* A brand new entry in the array */ + (void)PR_ATOMIC_INCREMENT(&cvar->notify_pending); + notified->cv[index].times = (broadcast) ? -1 : 1; + notified->cv[index].cv = cvar; + notified->length += 1; +} /* pt_PostNotifyToCvar */ + +PR_IMPLEMENT(PRCondVar*) PR_NewCondVar(PRLock *lock) +{ + PRCondVar *cv = PR_NEW(PRCondVar); + PR_ASSERT(lock != NULL); + if (cv != NULL) + { + int rv = _PT_PTHREAD_COND_INIT(cv->cv, _pt_cvar_attr); + PR_ASSERT(0 == rv); + if (0 == rv) + { + cv->lock = lock; + cv->notify_pending = 0; +#if defined(DEBUG) + pt_debug.cvars_created += 1; +#endif + } + else + { + PR_DELETE(cv); + cv = NULL; + } + } + return cv; +} /* PR_NewCondVar */ + +PR_IMPLEMENT(void) PR_DestroyCondVar(PRCondVar *cvar) +{ + if (0 > PR_ATOMIC_DECREMENT(&cvar->notify_pending)) + { + PRIntn rv = pthread_cond_destroy(&cvar->cv); +#if defined(DEBUG) + PR_ASSERT(0 == rv); + memset(cvar, 0xaf, sizeof(PRCondVar)); + pt_debug.cvars_destroyed += 1; +#else + (void)rv; +#endif + PR_Free(cvar); + } +} /* PR_DestroyCondVar */ + +PR_IMPLEMENT(PRStatus) PR_WaitCondVar(PRCondVar *cvar, PRIntervalTime timeout) +{ + PRIntn rv; + PRThread *thred = PR_GetCurrentThread(); + + PR_ASSERT(cvar != NULL); + /* We'd better be locked */ + PR_ASSERT(_PT_PTHREAD_MUTEX_IS_LOCKED(cvar->lock->mutex)); + PR_ASSERT(PR_TRUE == cvar->lock->locked); + /* and it better be by us */ + PR_ASSERT(pthread_equal(cvar->lock->owner, pthread_self())); + + if (_PT_THREAD_INTERRUPTED(thred)) { + goto aborted; + } + + /* + * The thread waiting is used for PR_Interrupt + */ + thred->waiting = cvar; /* this is where we're waiting */ + + /* + * If we have pending notifies, post them now. + * + * This is not optimal. We're going to post these notifies + * while we're holding the lock. That means on MP systems + * that they are going to collide for the lock that we will + * hold until we actually wait. + */ + if (0 != cvar->lock->notified.length) { + pt_PostNotifies(cvar->lock, PR_FALSE); + } + + /* + * We're surrendering the lock, so clear out the locked field. + */ + cvar->lock->locked = PR_FALSE; + + if (timeout == PR_INTERVAL_NO_TIMEOUT) { + rv = pthread_cond_wait(&cvar->cv, &cvar->lock->mutex); + } + else { + rv = pt_TimedWait(&cvar->cv, &cvar->lock->mutex, timeout); + } + + /* We just got the lock back - this better be empty */ + PR_ASSERT(PR_FALSE == cvar->lock->locked); + cvar->lock->locked = PR_TRUE; + cvar->lock->owner = pthread_self(); + + PR_ASSERT(0 == cvar->lock->notified.length); + thred->waiting = NULL; /* and now we're not */ + if (_PT_THREAD_INTERRUPTED(thred)) { + goto aborted; + } + if (rv != 0) + { + _PR_MD_MAP_DEFAULT_ERROR(rv); + return PR_FAILURE; + } + return PR_SUCCESS; + +aborted: + PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0); + thred->state &= ~PT_THREAD_ABORTED; + return PR_FAILURE; +} /* PR_WaitCondVar */ + +PR_IMPLEMENT(PRStatus) PR_NotifyCondVar(PRCondVar *cvar) +{ + PR_ASSERT(cvar != NULL); + pt_PostNotifyToCvar(cvar, PR_FALSE); + return PR_SUCCESS; +} /* PR_NotifyCondVar */ + +PR_IMPLEMENT(PRStatus) PR_NotifyAllCondVar(PRCondVar *cvar) +{ + PR_ASSERT(cvar != NULL); + pt_PostNotifyToCvar(cvar, PR_TRUE); + return PR_SUCCESS; +} /* PR_NotifyAllCondVar */ + +/**************************************************************/ +/**************************************************************/ +/***************************MONITORS***************************/ +/**************************************************************/ +/**************************************************************/ + +/* + * Notifies just get posted to the monitor. The actual notification is done + * when the monitor is fully exited so that MP systems don't contend for a + * monitor that they can't enter. + */ +static void pt_PostNotifyToMonitor(PRMonitor *mon, PRBool broadcast) +{ + PR_ASSERT(NULL != mon); + PR_ASSERT_CURRENT_THREAD_IN_MONITOR(mon); + + /* mon->notifyTimes is protected by the monitor, so we don't need to + * acquire mon->lock. + */ + if (broadcast) { + mon->notifyTimes = -1; + } + else if (-1 != mon->notifyTimes) { + mon->notifyTimes += 1; + } +} /* pt_PostNotifyToMonitor */ + +static void pt_PostNotifiesFromMonitor(pthread_cond_t *cv, PRIntn times) +{ + PRIntn rv; + + /* + * Time to actually notify any waits that were affected while the monitor + * was entered. + */ + PR_ASSERT(NULL != cv); + PR_ASSERT(0 != times); + if (-1 == times) + { + rv = pthread_cond_broadcast(cv); + PR_ASSERT(0 == rv); + } + else + { + while (times-- > 0) + { + rv = pthread_cond_signal(cv); + PR_ASSERT(0 == rv); + } + } +} /* pt_PostNotifiesFromMonitor */ + +PR_IMPLEMENT(PRMonitor*) PR_NewMonitor(void) +{ + PRMonitor *mon; + int rv; + + if (!_pr_initialized) { + _PR_ImplicitInitialization(); + } + + mon = PR_NEWZAP(PRMonitor); + if (mon == NULL) + { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + return NULL; + } + + rv = _PT_PTHREAD_MUTEX_INIT(mon->lock, _pt_mattr); + PR_ASSERT(0 == rv); + if (0 != rv) { + goto error1; + } + + _PT_PTHREAD_INVALIDATE_THR_HANDLE(mon->owner); + + rv = _PT_PTHREAD_COND_INIT(mon->entryCV, _pt_cvar_attr); + PR_ASSERT(0 == rv); + if (0 != rv) { + goto error2; + } + + rv = _PT_PTHREAD_COND_INIT(mon->waitCV, _pt_cvar_attr); + PR_ASSERT(0 == rv); + if (0 != rv) { + goto error3; + } + + mon->notifyTimes = 0; + mon->entryCount = 0; + mon->refCount = 1; + mon->name = NULL; + return mon; + +error3: + pthread_cond_destroy(&mon->entryCV); +error2: + pthread_mutex_destroy(&mon->lock); +error1: + PR_Free(mon); + _PR_MD_MAP_DEFAULT_ERROR(rv); + return NULL; +} /* PR_NewMonitor */ + +PR_IMPLEMENT(PRMonitor*) PR_NewNamedMonitor(const char* name) +{ + PRMonitor* mon = PR_NewMonitor(); + if (mon) { + mon->name = name; + } + return mon; +} + +PR_IMPLEMENT(void) PR_DestroyMonitor(PRMonitor *mon) +{ + int rv; + + PR_ASSERT(mon != NULL); + if (PR_ATOMIC_DECREMENT(&mon->refCount) == 0) + { + rv = pthread_cond_destroy(&mon->waitCV); PR_ASSERT(0 == rv); + rv = pthread_cond_destroy(&mon->entryCV); PR_ASSERT(0 == rv); + rv = pthread_mutex_destroy(&mon->lock); PR_ASSERT(0 == rv); +#if defined(DEBUG) + memset(mon, 0xaf, sizeof(PRMonitor)); +#endif + PR_Free(mon); + } +} /* PR_DestroyMonitor */ + +/* The GC uses this; it is quite arguably a bad interface. I'm just + * duplicating it for now - XXXMB + */ +PR_IMPLEMENT(PRIntn) PR_GetMonitorEntryCount(PRMonitor *mon) +{ + pthread_t self = pthread_self(); + PRIntn rv; + PRIntn count = 0; + + rv = pthread_mutex_lock(&mon->lock); + PR_ASSERT(0 == rv); + if (pthread_equal(mon->owner, self)) { + count = mon->entryCount; + } + rv = pthread_mutex_unlock(&mon->lock); + PR_ASSERT(0 == rv); + return count; +} + +PR_IMPLEMENT(void) PR_AssertCurrentThreadInMonitor(PRMonitor *mon) +{ +#if defined(DEBUG) || defined(FORCE_PR_ASSERT) + PRIntn rv; + + rv = pthread_mutex_lock(&mon->lock); + PR_ASSERT(0 == rv); + PR_ASSERT(mon->entryCount != 0 && + pthread_equal(mon->owner, pthread_self())); + rv = pthread_mutex_unlock(&mon->lock); + PR_ASSERT(0 == rv); +#endif +} + +PR_IMPLEMENT(void) PR_EnterMonitor(PRMonitor *mon) +{ + pthread_t self = pthread_self(); + PRIntn rv; + + PR_ASSERT(mon != NULL); + rv = pthread_mutex_lock(&mon->lock); + PR_ASSERT(0 == rv); + if (mon->entryCount != 0) + { + if (pthread_equal(mon->owner, self)) { + goto done; + } + while (mon->entryCount != 0) + { + rv = pthread_cond_wait(&mon->entryCV, &mon->lock); + PR_ASSERT(0 == rv); + } + } + /* and now I have the monitor */ + PR_ASSERT(0 == mon->notifyTimes); + PR_ASSERT(_PT_PTHREAD_THR_HANDLE_IS_INVALID(mon->owner)); + _PT_PTHREAD_COPY_THR_HANDLE(self, mon->owner); + +done: + mon->entryCount += 1; + rv = pthread_mutex_unlock(&mon->lock); + PR_ASSERT(0 == rv); +} /* PR_EnterMonitor */ + +PR_IMPLEMENT(PRStatus) PR_ExitMonitor(PRMonitor *mon) +{ + pthread_t self = pthread_self(); + PRIntn rv; + PRBool notifyEntryWaiter = PR_FALSE; + PRIntn notifyTimes = 0; + + PR_ASSERT(mon != NULL); + rv = pthread_mutex_lock(&mon->lock); + PR_ASSERT(0 == rv); + /* the entries should be > 0 and we'd better be the owner */ + PR_ASSERT(mon->entryCount > 0); + PR_ASSERT(pthread_equal(mon->owner, self)); + if (mon->entryCount == 0 || !pthread_equal(mon->owner, self)) + { + rv = pthread_mutex_unlock(&mon->lock); + PR_ASSERT(0 == rv); + return PR_FAILURE; + } + + mon->entryCount -= 1; /* reduce by one */ + if (mon->entryCount == 0) + { + /* and if it transitioned to zero - notify an entry waiter */ + /* make the owner unknown */ + _PT_PTHREAD_INVALIDATE_THR_HANDLE(mon->owner); + notifyEntryWaiter = PR_TRUE; + notifyTimes = mon->notifyTimes; + mon->notifyTimes = 0; + /* We will access the members of 'mon' after unlocking mon->lock. + * Add a reference. */ + PR_ATOMIC_INCREMENT(&mon->refCount); + } + rv = pthread_mutex_unlock(&mon->lock); + PR_ASSERT(0 == rv); + if (notifyEntryWaiter) + { + if (notifyTimes) { + pt_PostNotifiesFromMonitor(&mon->waitCV, notifyTimes); + } + rv = pthread_cond_signal(&mon->entryCV); + PR_ASSERT(0 == rv); + /* We are done accessing the members of 'mon'. Release the + * reference. */ + PR_DestroyMonitor(mon); + } + return PR_SUCCESS; +} /* PR_ExitMonitor */ + +PR_IMPLEMENT(PRStatus) PR_Wait(PRMonitor *mon, PRIntervalTime timeout) +{ + PRStatus rv; + PRUint32 saved_entries; + pthread_t saved_owner; + + PR_ASSERT(mon != NULL); + rv = pthread_mutex_lock(&mon->lock); + PR_ASSERT(0 == rv); + /* the entries better be positive */ + PR_ASSERT(mon->entryCount > 0); + /* and it better be owned by us */ + PR_ASSERT(pthread_equal(mon->owner, pthread_self())); + + /* tuck these away 'till later */ + saved_entries = mon->entryCount; + mon->entryCount = 0; + _PT_PTHREAD_COPY_THR_HANDLE(mon->owner, saved_owner); + _PT_PTHREAD_INVALIDATE_THR_HANDLE(mon->owner); + /* + * If we have pending notifies, post them now. + * + * This is not optimal. We're going to post these notifies + * while we're holding the lock. That means on MP systems + * that they are going to collide for the lock that we will + * hold until we actually wait. + */ + if (0 != mon->notifyTimes) + { + pt_PostNotifiesFromMonitor(&mon->waitCV, mon->notifyTimes); + mon->notifyTimes = 0; + } + rv = pthread_cond_signal(&mon->entryCV); + PR_ASSERT(0 == rv); + + if (timeout == PR_INTERVAL_NO_TIMEOUT) { + rv = pthread_cond_wait(&mon->waitCV, &mon->lock); + } + else { + rv = pt_TimedWait(&mon->waitCV, &mon->lock, timeout); + } + PR_ASSERT(0 == rv); + + while (mon->entryCount != 0) + { + rv = pthread_cond_wait(&mon->entryCV, &mon->lock); + PR_ASSERT(0 == rv); + } + PR_ASSERT(0 == mon->notifyTimes); + /* reinstate the interesting information */ + mon->entryCount = saved_entries; + _PT_PTHREAD_COPY_THR_HANDLE(saved_owner, mon->owner); + + rv = pthread_mutex_unlock(&mon->lock); + PR_ASSERT(0 == rv); + return rv; +} /* PR_Wait */ + +PR_IMPLEMENT(PRStatus) PR_Notify(PRMonitor *mon) +{ + pt_PostNotifyToMonitor(mon, PR_FALSE); + return PR_SUCCESS; +} /* PR_Notify */ + +PR_IMPLEMENT(PRStatus) PR_NotifyAll(PRMonitor *mon) +{ + pt_PostNotifyToMonitor(mon, PR_TRUE); + return PR_SUCCESS; +} /* PR_NotifyAll */ + +/**************************************************************/ +/**************************************************************/ +/**************************SEMAPHORES**************************/ +/**************************************************************/ +/**************************************************************/ +PR_IMPLEMENT(void) PR_PostSem(PRSemaphore *semaphore) +{ + static PRBool unwarned = PR_TRUE; + if (unwarned) unwarned = _PR_Obsolete( + "PR_PostSem", "locks & condition variables"); + PR_Lock(semaphore->cvar->lock); + PR_NotifyCondVar(semaphore->cvar); + semaphore->count += 1; + PR_Unlock(semaphore->cvar->lock); +} /* PR_PostSem */ + +PR_IMPLEMENT(PRStatus) PR_WaitSem(PRSemaphore *semaphore) +{ + PRStatus status = PR_SUCCESS; + static PRBool unwarned = PR_TRUE; + if (unwarned) unwarned = _PR_Obsolete( + "PR_WaitSem", "locks & condition variables"); + PR_Lock(semaphore->cvar->lock); + while ((semaphore->count == 0) && (PR_SUCCESS == status)) { + status = PR_WaitCondVar(semaphore->cvar, PR_INTERVAL_NO_TIMEOUT); + } + if (PR_SUCCESS == status) { + semaphore->count -= 1; + } + PR_Unlock(semaphore->cvar->lock); + return status; +} /* PR_WaitSem */ + +PR_IMPLEMENT(void) PR_DestroySem(PRSemaphore *semaphore) +{ + static PRBool unwarned = PR_TRUE; + if (unwarned) unwarned = _PR_Obsolete( + "PR_DestroySem", "locks & condition variables"); + PR_DestroyLock(semaphore->cvar->lock); + PR_DestroyCondVar(semaphore->cvar); + PR_Free(semaphore); +} /* PR_DestroySem */ + +PR_IMPLEMENT(PRSemaphore*) PR_NewSem(PRUintn value) +{ + PRSemaphore *semaphore; + static PRBool unwarned = PR_TRUE; + if (!_pr_initialized) { + _PR_ImplicitInitialization(); + } + + if (unwarned) unwarned = _PR_Obsolete( + "PR_NewSem", "locks & condition variables"); + + semaphore = PR_NEWZAP(PRSemaphore); + if (NULL != semaphore) + { + PRLock *lock = PR_NewLock(); + if (NULL != lock) + { + semaphore->cvar = PR_NewCondVar(lock); + if (NULL != semaphore->cvar) + { + semaphore->count = value; + return semaphore; + } + PR_DestroyLock(lock); + } + PR_Free(semaphore); + } + return NULL; +} + +/* + * Define the interprocess named semaphore functions. + * There are three implementations: + * 1. POSIX semaphore based; + * 2. System V semaphore based; + * 3. unsupported (fails with PR_NOT_IMPLEMENTED_ERROR). + */ + +#ifdef _PR_HAVE_POSIX_SEMAPHORES +#include <fcntl.h> + +PR_IMPLEMENT(PRSem *) PR_OpenSemaphore( + const char *name, + PRIntn flags, + PRIntn mode, + PRUintn value) +{ + PRSem *sem; + char osname[PR_IPC_NAME_SIZE]; + + if (_PR_MakeNativeIPCName(name, osname, sizeof(osname), _PRIPCSem) + == PR_FAILURE) + { + return NULL; + } + + sem = PR_NEW(PRSem); + if (NULL == sem) + { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + return NULL; + } + + if (flags & PR_SEM_CREATE) + { + int oflag = O_CREAT; + + if (flags & PR_SEM_EXCL) { + oflag |= O_EXCL; + } + sem->sem = sem_open(osname, oflag, mode, value); + } + else + { +#ifdef HPUX + /* Pass 0 as the mode and value arguments to work around a bug. */ + sem->sem = sem_open(osname, 0, 0, 0); +#else + sem->sem = sem_open(osname, 0); +#endif + } + if ((sem_t *) -1 == sem->sem) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + PR_Free(sem); + return NULL; + } + return sem; +} + +PR_IMPLEMENT(PRStatus) PR_WaitSemaphore(PRSem *sem) +{ + int rv; + rv = sem_wait(sem->sem); + if (0 != rv) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + return PR_SUCCESS; +} + +PR_IMPLEMENT(PRStatus) PR_PostSemaphore(PRSem *sem) +{ + int rv; + rv = sem_post(sem->sem); + if (0 != rv) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + return PR_SUCCESS; +} + +PR_IMPLEMENT(PRStatus) PR_CloseSemaphore(PRSem *sem) +{ + int rv; + rv = sem_close(sem->sem); + if (0 != rv) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + PR_Free(sem); + return PR_SUCCESS; +} + +PR_IMPLEMENT(PRStatus) PR_DeleteSemaphore(const char *name) +{ + int rv; + char osname[PR_IPC_NAME_SIZE]; + + if (_PR_MakeNativeIPCName(name, osname, sizeof(osname), _PRIPCSem) + == PR_FAILURE) + { + return PR_FAILURE; + } + rv = sem_unlink(osname); + if (0 != rv) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + return PR_SUCCESS; +} + +#elif defined(_PR_HAVE_SYSV_SEMAPHORES) + +#include <fcntl.h> +#include <sys/sem.h> + +/* + * From the semctl(2) man page in glibc 2.0 + */ +#if (defined(__GNU_LIBRARY__) && !defined(_SEM_SEMUN_UNDEFINED)) \ + || (defined(FREEBSD) && __FreeBSD_version < 1200059) \ + || defined(OPENBSD) || defined(BSDI) \ + || defined(DARWIN) +/* union semun is defined by including <sys/sem.h> */ +#else +/* according to X/OPEN we have to define it ourselves */ +union semun { + int val; + struct semid_ds *buf; + unsigned short *array; +}; +#endif + +/* + * 'a' (97) is the final closing price of NSCP stock. + */ +#define NSPR_IPC_KEY_ID 'a' /* the id argument for ftok() */ + +#define NSPR_SEM_MODE 0666 + +PR_IMPLEMENT(PRSem *) PR_OpenSemaphore( + const char *name, + PRIntn flags, + PRIntn mode, + PRUintn value) +{ + PRSem *sem; + key_t key; + union semun arg; + struct sembuf sop; + struct semid_ds seminfo; +#define MAX_TRIES 60 + PRIntn i; + char osname[PR_IPC_NAME_SIZE]; + + if (_PR_MakeNativeIPCName(name, osname, sizeof(osname), _PRIPCSem) + == PR_FAILURE) + { + return NULL; + } + + /* Make sure the file exists before calling ftok. */ + if (flags & PR_SEM_CREATE) + { + int osfd = open(osname, O_RDWR|O_CREAT, mode); + if (-1 == osfd) + { + _PR_MD_MAP_OPEN_ERROR(errno); + return NULL; + } + if (close(osfd) == -1) + { + _PR_MD_MAP_CLOSE_ERROR(errno); + return NULL; + } + } + key = ftok(osname, NSPR_IPC_KEY_ID); + if ((key_t)-1 == key) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return NULL; + } + + sem = PR_NEW(PRSem); + if (NULL == sem) + { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + return NULL; + } + + if (flags & PR_SEM_CREATE) + { + sem->semid = semget(key, 1, mode|IPC_CREAT|IPC_EXCL); + if (sem->semid >= 0) + { + /* creator of a semaphore is responsible for initializing it */ + arg.val = 0; + if (semctl(sem->semid, 0, SETVAL, arg) == -1) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + PR_Free(sem); + return NULL; + } + /* call semop to set sem_otime to nonzero */ + sop.sem_num = 0; + sop.sem_op = value; + sop.sem_flg = 0; + if (semop(sem->semid, &sop, 1) == -1) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + PR_Free(sem); + return NULL; + } + return sem; + } + + if (errno != EEXIST || flags & PR_SEM_EXCL) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + PR_Free(sem); + return NULL; + } + } + + sem->semid = semget(key, 1, NSPR_SEM_MODE); + if (sem->semid == -1) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + PR_Free(sem); + return NULL; + } + for (i = 0; i < MAX_TRIES; i++) + { + arg.buf = &seminfo; + semctl(sem->semid, 0, IPC_STAT, arg); + if (seminfo.sem_otime != 0) { + break; + } + sleep(1); + } + if (i == MAX_TRIES) + { + PR_SetError(PR_IO_TIMEOUT_ERROR, 0); + PR_Free(sem); + return NULL; + } + return sem; +} + +PR_IMPLEMENT(PRStatus) PR_WaitSemaphore(PRSem *sem) +{ + struct sembuf sop; + + sop.sem_num = 0; + sop.sem_op = -1; + sop.sem_flg = 0; + if (semop(sem->semid, &sop, 1) == -1) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + return PR_SUCCESS; +} + +PR_IMPLEMENT(PRStatus) PR_PostSemaphore(PRSem *sem) +{ + struct sembuf sop; + + sop.sem_num = 0; + sop.sem_op = 1; + sop.sem_flg = 0; + if (semop(sem->semid, &sop, 1) == -1) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + return PR_SUCCESS; +} + +PR_IMPLEMENT(PRStatus) PR_CloseSemaphore(PRSem *sem) +{ + PR_Free(sem); + return PR_SUCCESS; +} + +PR_IMPLEMENT(PRStatus) PR_DeleteSemaphore(const char *name) +{ + key_t key; + int semid; + /* On some systems (e.g., glibc 2.0) semctl requires a fourth argument */ + union semun unused; + char osname[PR_IPC_NAME_SIZE]; + + if (_PR_MakeNativeIPCName(name, osname, sizeof(osname), _PRIPCSem) + == PR_FAILURE) + { + return PR_FAILURE; + } + key = ftok(osname, NSPR_IPC_KEY_ID); + if ((key_t) -1 == key) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + if (unlink(osname) == -1) + { + _PR_MD_MAP_UNLINK_ERROR(errno); + return PR_FAILURE; + } + semid = semget(key, 1, NSPR_SEM_MODE); + if (-1 == semid) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + unused.val = 0; + if (semctl(semid, 0, IPC_RMID, unused) == -1) + { + _PR_MD_MAP_DEFAULT_ERROR(errno); + return PR_FAILURE; + } + return PR_SUCCESS; +} + +#else /* neither POSIX nor System V semaphores are available */ + +PR_IMPLEMENT(PRSem *) PR_OpenSemaphore( + const char *name, + PRIntn flags, + PRIntn mode, + PRUintn value) +{ + PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0); + return NULL; +} + +PR_IMPLEMENT(PRStatus) PR_WaitSemaphore(PRSem *sem) +{ + PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0); + return PR_FAILURE; +} + +PR_IMPLEMENT(PRStatus) PR_PostSemaphore(PRSem *sem) +{ + PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0); + return PR_FAILURE; +} + +PR_IMPLEMENT(PRStatus) PR_CloseSemaphore(PRSem *sem) +{ + PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0); + return PR_FAILURE; +} + +PR_IMPLEMENT(PRStatus) PR_DeleteSemaphore(const char *name) +{ + PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0); + return PR_FAILURE; +} + +#endif /* end of interprocess named semaphore functions */ + +/**************************************************************/ +/**************************************************************/ +/******************ROUTINES FOR DCE EMULATION******************/ +/**************************************************************/ +/**************************************************************/ + +#include "prpdce.h" + +PR_IMPLEMENT(PRStatus) PRP_TryLock(PRLock *lock) +{ + PRIntn rv = pthread_mutex_trylock(&lock->mutex); + if (rv == 0) + { + PR_ASSERT(PR_FALSE == lock->locked); + lock->locked = PR_TRUE; + lock->owner = pthread_self(); + } + /* XXX set error code? */ + return (0 == rv) ? PR_SUCCESS : PR_FAILURE; +} /* PRP_TryLock */ + +PR_IMPLEMENT(PRCondVar*) PRP_NewNakedCondVar(void) +{ + PRCondVar *cv; + + if (!_pr_initialized) { + _PR_ImplicitInitialization(); + } + + cv = PR_NEW(PRCondVar); + if (cv != NULL) + { + int rv; + rv = _PT_PTHREAD_COND_INIT(cv->cv, _pt_cvar_attr); + PR_ASSERT(0 == rv); + if (0 == rv) + { + cv->lock = _PR_NAKED_CV_LOCK; + } + else + { + PR_DELETE(cv); + cv = NULL; + } + } + return cv; +} /* PRP_NewNakedCondVar */ + +PR_IMPLEMENT(void) PRP_DestroyNakedCondVar(PRCondVar *cvar) +{ + int rv; + rv = pthread_cond_destroy(&cvar->cv); PR_ASSERT(0 == rv); +#if defined(DEBUG) + memset(cvar, 0xaf, sizeof(PRCondVar)); +#endif + PR_Free(cvar); +} /* PRP_DestroyNakedCondVar */ + +PR_IMPLEMENT(PRStatus) PRP_NakedWait( + PRCondVar *cvar, PRLock *ml, PRIntervalTime timeout) +{ + PRIntn rv; + PR_ASSERT(cvar != NULL); + /* XXX do we really want to assert this in a naked wait? */ + PR_ASSERT(_PT_PTHREAD_MUTEX_IS_LOCKED(ml->mutex)); + if (timeout == PR_INTERVAL_NO_TIMEOUT) { + rv = pthread_cond_wait(&cvar->cv, &ml->mutex); + } + else { + rv = pt_TimedWait(&cvar->cv, &ml->mutex, timeout); + } + if (rv != 0) + { + _PR_MD_MAP_DEFAULT_ERROR(rv); + return PR_FAILURE; + } + return PR_SUCCESS; +} /* PRP_NakedWait */ + +PR_IMPLEMENT(PRStatus) PRP_NakedNotify(PRCondVar *cvar) +{ + int rv; + PR_ASSERT(cvar != NULL); + rv = pthread_cond_signal(&cvar->cv); + PR_ASSERT(0 == rv); + return PR_SUCCESS; +} /* PRP_NakedNotify */ + +PR_IMPLEMENT(PRStatus) PRP_NakedBroadcast(PRCondVar *cvar) +{ + int rv; + PR_ASSERT(cvar != NULL); + rv = pthread_cond_broadcast(&cvar->cv); + PR_ASSERT(0 == rv); + return PR_SUCCESS; +} /* PRP_NakedBroadcast */ + +#endif /* defined(_PR_PTHREADS) */ + +/* ptsynch.c */ |