diff options
Diffstat (limited to 'nsprpub/pr/src/threads/combined/prucv.c')
| -rw-r--r-- | nsprpub/pr/src/threads/combined/prucv.c | 655 |
1 files changed, 655 insertions, 0 deletions
diff --git a/nsprpub/pr/src/threads/combined/prucv.c b/nsprpub/pr/src/threads/combined/prucv.c new file mode 100644 index 000000000..d0bf4c422 --- /dev/null +++ b/nsprpub/pr/src/threads/combined/prucv.c @@ -0,0 +1,655 @@ +/* -*- 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/. */ + + +#include "primpl.h" +#include "prinrval.h" +#include "prtypes.h" + +#if defined(WIN95) +/* +** Some local variables report warnings on Win95 because the code paths +** using them are conditioned on HAVE_CUSTOME_USER_THREADS. +** The pragma suppresses the warning. +** +*/ +#pragma warning(disable : 4101) +#endif + + +/* +** Notify one thread that it has finished waiting on a condition variable +** Caller must hold the _PR_CVAR_LOCK(cv) +*/ +PRBool _PR_NotifyThread (PRThread *thread, PRThread *me) +{ + PRBool rv; + + PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0); + + _PR_THREAD_LOCK(thread); + PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD)); + if ( !_PR_IS_NATIVE_THREAD(thread) ) { + if (thread->wait.cvar != NULL) { + thread->wait.cvar = NULL; + + _PR_SLEEPQ_LOCK(thread->cpu); + /* The notify and timeout can collide; in which case both may + * attempt to delete from the sleepQ; only let one do it. + */ + if (thread->flags & (_PR_ON_SLEEPQ|_PR_ON_PAUSEQ)) + _PR_DEL_SLEEPQ(thread, PR_TRUE); + _PR_SLEEPQ_UNLOCK(thread->cpu); + + if (thread->flags & _PR_SUSPENDING) { + /* + * set thread state to SUSPENDED; a Resume operation + * on the thread will move it to the runQ + */ + thread->state = _PR_SUSPENDED; + _PR_MISCQ_LOCK(thread->cpu); + _PR_ADD_SUSPENDQ(thread, thread->cpu); + _PR_MISCQ_UNLOCK(thread->cpu); + _PR_THREAD_UNLOCK(thread); + } else { + /* Make thread runnable */ + thread->state = _PR_RUNNABLE; + _PR_THREAD_UNLOCK(thread); + + _PR_AddThreadToRunQ(me, thread); + _PR_MD_WAKEUP_WAITER(thread); + } + + rv = PR_TRUE; + } else { + /* Thread has already been notified */ + _PR_THREAD_UNLOCK(thread); + rv = PR_FALSE; + } + } else { /* If the thread is a native thread */ + if (thread->wait.cvar) { + thread->wait.cvar = NULL; + + if (thread->flags & _PR_SUSPENDING) { + /* + * set thread state to SUSPENDED; a Resume operation + * on the thread will enable the thread to run + */ + thread->state = _PR_SUSPENDED; + } else + thread->state = _PR_RUNNING; + _PR_THREAD_UNLOCK(thread); + _PR_MD_WAKEUP_WAITER(thread); + rv = PR_TRUE; + } else { + _PR_THREAD_UNLOCK(thread); + rv = PR_FALSE; + } + } + + return rv; +} + +/* + * Notify thread waiting on cvar; called when thread is interrupted + * The thread lock is held on entry and released before return + */ +void _PR_NotifyLockedThread (PRThread *thread) +{ + PRThread *me = _PR_MD_CURRENT_THREAD(); + PRCondVar *cvar; + PRThreadPriority pri; + + if ( !_PR_IS_NATIVE_THREAD(me)) + PR_ASSERT(_PR_MD_GET_INTSOFF() != 0); + + cvar = thread->wait.cvar; + thread->wait.cvar = NULL; + _PR_THREAD_UNLOCK(thread); + + _PR_CVAR_LOCK(cvar); + _PR_THREAD_LOCK(thread); + + if (!_PR_IS_NATIVE_THREAD(thread)) { + _PR_SLEEPQ_LOCK(thread->cpu); + /* The notify and timeout can collide; in which case both may + * attempt to delete from the sleepQ; only let one do it. + */ + if (thread->flags & (_PR_ON_SLEEPQ|_PR_ON_PAUSEQ)) + _PR_DEL_SLEEPQ(thread, PR_TRUE); + _PR_SLEEPQ_UNLOCK(thread->cpu); + + /* Make thread runnable */ + pri = thread->priority; + thread->state = _PR_RUNNABLE; + + PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD)); + + _PR_AddThreadToRunQ(me, thread); + _PR_THREAD_UNLOCK(thread); + + _PR_MD_WAKEUP_WAITER(thread); + } else { + if (thread->flags & _PR_SUSPENDING) { + /* + * set thread state to SUSPENDED; a Resume operation + * on the thread will enable the thread to run + */ + thread->state = _PR_SUSPENDED; + } else + thread->state = _PR_RUNNING; + _PR_THREAD_UNLOCK(thread); + _PR_MD_WAKEUP_WAITER(thread); + } + + _PR_CVAR_UNLOCK(cvar); + return; +} + +/* +** Make the given thread wait for the given condition variable +*/ +PRStatus _PR_WaitCondVar( + PRThread *thread, PRCondVar *cvar, PRLock *lock, PRIntervalTime timeout) +{ + PRIntn is; + PRStatus rv = PR_SUCCESS; + + PR_ASSERT(thread == _PR_MD_CURRENT_THREAD()); + PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD)); + +#ifdef _PR_GLOBAL_THREADS_ONLY + if (_PR_PENDING_INTERRUPT(thread)) { + PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0); + thread->flags &= ~_PR_INTERRUPT; + return PR_FAILURE; + } + + thread->wait.cvar = cvar; + lock->owner = NULL; + _PR_MD_WAIT_CV(&cvar->md,&lock->ilock, timeout); + thread->wait.cvar = NULL; + lock->owner = thread; + if (_PR_PENDING_INTERRUPT(thread)) { + PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0); + thread->flags &= ~_PR_INTERRUPT; + return PR_FAILURE; + } + + return PR_SUCCESS; +#else /* _PR_GLOBAL_THREADS_ONLY */ + + if ( !_PR_IS_NATIVE_THREAD(thread)) + _PR_INTSOFF(is); + + _PR_CVAR_LOCK(cvar); + _PR_THREAD_LOCK(thread); + + if (_PR_PENDING_INTERRUPT(thread)) { + PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0); + thread->flags &= ~_PR_INTERRUPT; + _PR_CVAR_UNLOCK(cvar); + _PR_THREAD_UNLOCK(thread); + if ( !_PR_IS_NATIVE_THREAD(thread)) + _PR_INTSON(is); + return PR_FAILURE; + } + + thread->state = _PR_COND_WAIT; + thread->wait.cvar = cvar; + + /* + ** Put the caller thread on the condition variable's wait Q + */ + PR_APPEND_LINK(&thread->waitQLinks, &cvar->condQ); + + /* Note- for global scope threads, we don't put them on the + * global sleepQ, so each global thread must put itself + * to sleep only for the time it wants to. + */ + if ( !_PR_IS_NATIVE_THREAD(thread) ) { + _PR_SLEEPQ_LOCK(thread->cpu); + _PR_ADD_SLEEPQ(thread, timeout); + _PR_SLEEPQ_UNLOCK(thread->cpu); + } + _PR_CVAR_UNLOCK(cvar); + _PR_THREAD_UNLOCK(thread); + + /* + ** Release lock protecting the condition variable and thereby giving time + ** to the next thread which can potentially notify on the condition variable + */ + PR_Unlock(lock); + + PR_LOG(_pr_cvar_lm, PR_LOG_MIN, + ("PR_Wait: cvar=%p waiting for %d", cvar, timeout)); + + rv = _PR_MD_WAIT(thread, timeout); + + _PR_CVAR_LOCK(cvar); + PR_REMOVE_LINK(&thread->waitQLinks); + _PR_CVAR_UNLOCK(cvar); + + PR_LOG(_pr_cvar_lm, PR_LOG_MIN, + ("PR_Wait: cvar=%p done waiting", cvar)); + + if ( !_PR_IS_NATIVE_THREAD(thread)) + _PR_INTSON(is); + + /* Acquire lock again that we had just relinquished */ + PR_Lock(lock); + + if (_PR_PENDING_INTERRUPT(thread)) { + PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0); + thread->flags &= ~_PR_INTERRUPT; + return PR_FAILURE; + } + + return rv; +#endif /* _PR_GLOBAL_THREADS_ONLY */ +} + +void _PR_NotifyCondVar(PRCondVar *cvar, PRThread *me) +{ +#ifdef _PR_GLOBAL_THREADS_ONLY + _PR_MD_NOTIFY_CV(&cvar->md, &cvar->lock->ilock); +#else /* _PR_GLOBAL_THREADS_ONLY */ + + PRCList *q; + PRIntn is; + + if ( !_PR_IS_NATIVE_THREAD(me)) + _PR_INTSOFF(is); + PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0); + + _PR_CVAR_LOCK(cvar); + q = cvar->condQ.next; + while (q != &cvar->condQ) { + PR_LOG(_pr_cvar_lm, PR_LOG_MIN, ("_PR_NotifyCondVar: cvar=%p", cvar)); + if (_PR_THREAD_CONDQ_PTR(q)->wait.cvar) { + if (_PR_NotifyThread(_PR_THREAD_CONDQ_PTR(q), me) == PR_TRUE) + break; + } + q = q->next; + } + _PR_CVAR_UNLOCK(cvar); + + if ( !_PR_IS_NATIVE_THREAD(me)) + _PR_INTSON(is); + +#endif /* _PR_GLOBAL_THREADS_ONLY */ +} + +/* +** Cndition variable debugging log info. +*/ +PRUint32 _PR_CondVarToString(PRCondVar *cvar, char *buf, PRUint32 buflen) +{ + PRUint32 nb; + + if (cvar->lock->owner) { + nb = PR_snprintf(buf, buflen, "[%p] owner=%ld[%p]", + cvar, cvar->lock->owner->id, cvar->lock->owner); + } else { + nb = PR_snprintf(buf, buflen, "[%p]", cvar); + } + return nb; +} + +/* +** Expire condition variable waits that are ready to expire. "now" is the current +** time. +*/ +void _PR_ClockInterrupt(void) +{ + PRThread *thread, *me = _PR_MD_CURRENT_THREAD(); + _PRCPU *cpu = me->cpu; + PRIntervalTime elapsed, now; + + PR_ASSERT(_PR_MD_GET_INTSOFF() != 0); + /* Figure out how much time elapsed since the last clock tick */ + now = PR_IntervalNow(); + elapsed = now - cpu->last_clock; + cpu->last_clock = now; + + PR_LOG(_pr_clock_lm, PR_LOG_MAX, + ("ExpireWaits: elapsed=%lld usec", elapsed)); + + while(1) { + _PR_SLEEPQ_LOCK(cpu); + if (_PR_SLEEPQ(cpu).next == &_PR_SLEEPQ(cpu)) { + _PR_SLEEPQ_UNLOCK(cpu); + break; + } + + thread = _PR_THREAD_PTR(_PR_SLEEPQ(cpu).next); + PR_ASSERT(thread->cpu == cpu); + + if (elapsed < thread->sleep) { + thread->sleep -= elapsed; + _PR_SLEEPQMAX(thread->cpu) -= elapsed; + _PR_SLEEPQ_UNLOCK(cpu); + break; + } + _PR_SLEEPQ_UNLOCK(cpu); + + PR_ASSERT(!_PR_IS_NATIVE_THREAD(thread)); + + _PR_THREAD_LOCK(thread); + + if (thread->cpu != cpu) { + /* + ** The thread was switched to another CPU + ** between the time we unlocked the sleep + ** queue and the time we acquired the thread + ** lock, so it is none of our business now. + */ + _PR_THREAD_UNLOCK(thread); + continue; + } + + /* + ** Consume this sleeper's amount of elapsed time from the elapsed + ** time value. The next remaining piece of elapsed time will be + ** available for the next sleeping thread's timer. + */ + _PR_SLEEPQ_LOCK(cpu); + PR_ASSERT(!(thread->flags & _PR_ON_PAUSEQ)); + if (thread->flags & _PR_ON_SLEEPQ) { + _PR_DEL_SLEEPQ(thread, PR_FALSE); + elapsed -= thread->sleep; + _PR_SLEEPQ_UNLOCK(cpu); + } else { + /* Thread was already handled; Go get another one */ + _PR_SLEEPQ_UNLOCK(cpu); + _PR_THREAD_UNLOCK(thread); + continue; + } + + /* Notify the thread waiting on the condition variable */ + if (thread->flags & _PR_SUSPENDING) { + PR_ASSERT((thread->state == _PR_IO_WAIT) || + (thread->state == _PR_COND_WAIT)); + /* + ** Thread is suspended and its condition timeout + ** expired. Transfer thread from sleepQ to suspendQ. + */ + thread->wait.cvar = NULL; + _PR_MISCQ_LOCK(cpu); + thread->state = _PR_SUSPENDED; + _PR_ADD_SUSPENDQ(thread, cpu); + _PR_MISCQ_UNLOCK(cpu); + } else { + if (thread->wait.cvar) { + PRThreadPriority pri; + + /* Do work very similar to what _PR_NotifyThread does */ + PR_ASSERT( !_PR_IS_NATIVE_THREAD(thread) ); + + /* Make thread runnable */ + pri = thread->priority; + thread->state = _PR_RUNNABLE; + PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD)); + + PR_ASSERT(thread->cpu == cpu); + _PR_RUNQ_LOCK(cpu); + _PR_ADD_RUNQ(thread, cpu, pri); + _PR_RUNQ_UNLOCK(cpu); + + if (pri > me->priority) + _PR_SET_RESCHED_FLAG(); + + thread->wait.cvar = NULL; + + _PR_MD_WAKEUP_WAITER(thread); + + } else if (thread->io_pending == PR_TRUE) { + /* Need to put IO sleeper back on runq */ + int pri = thread->priority; + + thread->io_suspended = PR_TRUE; +#ifdef WINNT + /* + * For NT, record the cpu on which I/O was issued + * I/O cancellation is done on the same cpu + */ + thread->md.thr_bound_cpu = cpu; +#endif + + PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD)); + PR_ASSERT(thread->cpu == cpu); + thread->state = _PR_RUNNABLE; + _PR_RUNQ_LOCK(cpu); + _PR_ADD_RUNQ(thread, cpu, pri); + _PR_RUNQ_UNLOCK(cpu); + } + } + _PR_THREAD_UNLOCK(thread); + } +} + +/************************************************************************/ + +/* +** Create a new condition variable. +** "lock" is the lock to use with the condition variable. +** +** Condition variables are synchronization objects that threads can use +** to wait for some condition to occur. +** +** This may fail if memory is tight or if some operating system resource +** is low. +*/ +PR_IMPLEMENT(PRCondVar*) PR_NewCondVar(PRLock *lock) +{ + PRCondVar *cvar; + + cvar = PR_NEWZAP(PRCondVar); + if (cvar) { + if (_PR_InitCondVar(cvar, lock) != PR_SUCCESS) { + PR_DELETE(cvar); + return NULL; + } + } else { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + } + return cvar; +} + +PRStatus _PR_InitCondVar(PRCondVar *cvar, PRLock *lock) +{ + PR_ASSERT(lock != NULL); + +#ifdef _PR_GLOBAL_THREADS_ONLY + if(_PR_MD_NEW_CV(&cvar->md)) { + PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0); + return PR_FAILURE; + } +#endif + if (_PR_MD_NEW_LOCK(&(cvar->ilock)) != PR_SUCCESS) { + PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0); + return PR_FAILURE; + } + cvar->lock = lock; + PR_INIT_CLIST(&cvar->condQ); + return PR_SUCCESS; +} + +/* +** Destroy a condition variable. There must be no thread +** waiting on the condvar. The caller is responsible for guaranteeing +** that the condvar is no longer in use. +** +*/ +PR_IMPLEMENT(void) PR_DestroyCondVar(PRCondVar *cvar) +{ + _PR_FreeCondVar(cvar); + PR_DELETE(cvar); +} + +void _PR_FreeCondVar(PRCondVar *cvar) +{ + PR_ASSERT(cvar->condQ.next == &cvar->condQ); + +#ifdef _PR_GLOBAL_THREADS_ONLY + _PR_MD_FREE_CV(&cvar->md); +#endif + _PR_MD_FREE_LOCK(&(cvar->ilock)); +} + +/* +** Wait for a notify on the condition variable. Sleep for "tiemout" amount +** of ticks (if "timeout" is zero then the sleep is indefinite). While +** the thread is waiting it unlocks lock. When the wait has +** finished the thread regains control of the condition variable after +** locking the associated lock. +** +** The thread waiting on the condvar will be resumed when the condvar is +** notified (assuming the thread is the next in line to receive the +** notify) or when the timeout elapses. +** +** Returns PR_FAILURE if the caller has not locked the lock associated +** with the condition variable or the thread has been interrupted. +*/ +extern PRThread *suspendAllThread; +PR_IMPLEMENT(PRStatus) PR_WaitCondVar(PRCondVar *cvar, PRIntervalTime timeout) +{ + PRThread *me = _PR_MD_CURRENT_THREAD(); + + PR_ASSERT(cvar->lock->owner == me); + PR_ASSERT(me != suspendAllThread); + if (cvar->lock->owner != me) return PR_FAILURE; + + return _PR_WaitCondVar(me, cvar, cvar->lock, timeout); +} + +/* +** Notify the highest priority thread waiting on the condition +** variable. If a thread is waiting on the condition variable (using +** PR_Wait) then it is awakened and begins waiting on the lock. +*/ +PR_IMPLEMENT(PRStatus) PR_NotifyCondVar(PRCondVar *cvar) +{ + PRThread *me = _PR_MD_CURRENT_THREAD(); + + PR_ASSERT(cvar->lock->owner == me); + PR_ASSERT(me != suspendAllThread); + if (cvar->lock->owner != me) return PR_FAILURE; + + _PR_NotifyCondVar(cvar, me); + return PR_SUCCESS; +} + +/* +** Notify all of the threads waiting on the condition variable. All of +** threads are notified in turn. The highest priority thread will +** probably acquire the lock. +*/ +PR_IMPLEMENT(PRStatus) PR_NotifyAllCondVar(PRCondVar *cvar) +{ + PRCList *q; + PRIntn is; + PRThread *me = _PR_MD_CURRENT_THREAD(); + + PR_ASSERT(cvar->lock->owner == me); + if (cvar->lock->owner != me) return PR_FAILURE; + +#ifdef _PR_GLOBAL_THREADS_ONLY + _PR_MD_NOTIFYALL_CV(&cvar->md, &cvar->lock->ilock); + return PR_SUCCESS; +#else /* _PR_GLOBAL_THREADS_ONLY */ + if ( !_PR_IS_NATIVE_THREAD(me)) + _PR_INTSOFF(is); + _PR_CVAR_LOCK(cvar); + q = cvar->condQ.next; + while (q != &cvar->condQ) { + PR_LOG(_pr_cvar_lm, PR_LOG_MIN, ("PR_NotifyAll: cvar=%p", cvar)); + _PR_NotifyThread(_PR_THREAD_CONDQ_PTR(q), me); + q = q->next; + } + _PR_CVAR_UNLOCK(cvar); + if (!_PR_IS_NATIVE_THREAD(me)) + _PR_INTSON(is); + + return PR_SUCCESS; +#endif /* _PR_GLOBAL_THREADS_ONLY */ +} + + +/*********************************************************************/ +/*********************************************************************/ +/********************ROUTINES FOR DCE EMULATION***********************/ +/*********************************************************************/ +/*********************************************************************/ +#include "prpdce.h" + +PR_IMPLEMENT(PRCondVar*) PRP_NewNakedCondVar(void) +{ + PRCondVar *cvar = PR_NEWZAP(PRCondVar); + if (NULL != cvar) + { + if (_PR_MD_NEW_LOCK(&(cvar->ilock)) == PR_FAILURE) + { + PR_DELETE(cvar); cvar = NULL; + } + else + { + PR_INIT_CLIST(&cvar->condQ); + cvar->lock = _PR_NAKED_CV_LOCK; + } + + } + return cvar; +} + +PR_IMPLEMENT(void) PRP_DestroyNakedCondVar(PRCondVar *cvar) +{ + PR_ASSERT(cvar->condQ.next == &cvar->condQ); + PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock); + + _PR_MD_FREE_LOCK(&(cvar->ilock)); + + PR_DELETE(cvar); +} + +PR_IMPLEMENT(PRStatus) PRP_NakedWait( + PRCondVar *cvar, PRLock *lock, PRIntervalTime timeout) +{ + PRThread *me = _PR_MD_CURRENT_THREAD(); + PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock); + return _PR_WaitCondVar(me, cvar, lock, timeout); +} /* PRP_NakedWait */ + +PR_IMPLEMENT(PRStatus) PRP_NakedNotify(PRCondVar *cvar) +{ + PRThread *me = _PR_MD_CURRENT_THREAD(); + PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock); + + _PR_NotifyCondVar(cvar, me); + + return PR_SUCCESS; +} /* PRP_NakedNotify */ + +PR_IMPLEMENT(PRStatus) PRP_NakedBroadcast(PRCondVar *cvar) +{ + PRCList *q; + PRIntn is; + PRThread *me = _PR_MD_CURRENT_THREAD(); + PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock); + + if ( !_PR_IS_NATIVE_THREAD(me)) _PR_INTSOFF(is); + _PR_MD_LOCK( &(cvar->ilock) ); + q = cvar->condQ.next; + while (q != &cvar->condQ) { + PR_LOG(_pr_cvar_lm, PR_LOG_MIN, ("PR_NotifyAll: cvar=%p", cvar)); + _PR_NotifyThread(_PR_THREAD_CONDQ_PTR(q), me); + q = q->next; + } + _PR_MD_UNLOCK( &(cvar->ilock) ); + if (!_PR_IS_NATIVE_THREAD(me)) _PR_INTSON(is); + + return PR_SUCCESS; +} /* PRP_NakedBroadcast */ + |