prtpool.c

Netscape NSPR库源码

	tp->jobq.lock = PR_NewLock();
	if (NULL == tp->jobq.lock)
		goto failed;
	tp->jobq.cv = PR_NewCondVar(tp->jobq.lock);
	if (NULL == tp->jobq.cv)
		goto failed;
	tp->join_lock = PR_NewLock();
	if (NULL == tp->join_lock)
		goto failed;
#ifdef OPT_WINNT
	tp->jobq.nt_completion_port = CreateIoCompletionPort(INVALID_HANDLE_VALUE,
									NULL, 0, 0);
	if (NULL == tp->jobq.nt_completion_port)
		goto failed;
#endif

	tp->ioq.lock = PR_NewLock();
	if (NULL == tp->ioq.lock)
		goto failed;

	/* Timer queue */

	tp->timerq.lock = PR_NewLock();
	if (NULL == tp->timerq.lock)
		goto failed;
	tp->timerq.cv = PR_NewCondVar(tp->timerq.lock);
	if (NULL == tp->timerq.cv)
		goto failed;

	tp->shutdown_cv = PR_NewCondVar(tp->jobq.lock);
	if (NULL == tp->shutdown_cv)
		goto failed;
	tp->ioq.notify_fd = PR_NewPollableEvent();
	if (NULL == tp->ioq.notify_fd)
		goto failed;
	return tp;
failed:
	delete_threadpool(tp);
	PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
	return NULL;
}

/* Create thread pool */
PR_IMPLEMENT(PRThreadPool *)
PR_CreateThreadPool(PRInt32 initial_threads, PRInt32 max_threads,
                                PRUint32 stacksize)
{
PRThreadPool *tp;
PRThread *thr;
int i;
wthread *wthrp;

	tp = alloc_threadpool();
	if (NULL == tp)
		return NULL;

	tp->init_threads = initial_threads;
	tp->max_threads = max_threads;
	tp->stacksize = stacksize;
	PR_INIT_CLIST(&tp->jobq.list);
	PR_INIT_CLIST(&tp->ioq.list);
	PR_INIT_CLIST(&tp->timerq.list);
	PR_INIT_CLIST(&tp->jobq.wthreads);
	PR_INIT_CLIST(&tp->ioq.wthreads);
	PR_INIT_CLIST(&tp->timerq.wthreads);
	tp->shutdown = PR_FALSE;

	PR_Lock(tp->jobq.lock);
	for(i=0; i < initial_threads; ++i) {

		thr = PR_CreateThread(PR_USER_THREAD, wstart,
						tp, PR_PRIORITY_NORMAL,
						PR_GLOBAL_THREAD, PR_JOINABLE_THREAD,stacksize);
		PR_ASSERT(thr);
		wthrp = PR_NEWZAP(wthread);
		PR_ASSERT(wthrp);
		wthrp->thread = thr;
		PR_APPEND_LINK(&wthrp->links, &tp->jobq.wthreads);
	}
	tp->current_threads = initial_threads;

	thr = PR_CreateThread(PR_USER_THREAD, io_wstart,
					tp, PR_PRIORITY_NORMAL,
					PR_GLOBAL_THREAD,PR_JOINABLE_THREAD,stacksize);
	PR_ASSERT(thr);
	wthrp = PR_NEWZAP(wthread);
	PR_ASSERT(wthrp);
	wthrp->thread = thr;
	PR_APPEND_LINK(&wthrp->links, &tp->ioq.wthreads);

	thr = PR_CreateThread(PR_USER_THREAD, timer_wstart,
					tp, PR_PRIORITY_NORMAL,
					PR_GLOBAL_THREAD,PR_JOINABLE_THREAD,stacksize);
	PR_ASSERT(thr);
	wthrp = PR_NEWZAP(wthread);
	PR_ASSERT(wthrp);
	wthrp->thread = thr;
	PR_APPEND_LINK(&wthrp->links, &tp->timerq.wthreads);

	PR_Unlock(tp->jobq.lock);
	return tp;
}

static void
delete_job(PRJob *jobp)
{
	if (NULL != jobp) {
		if (NULL != jobp->join_cv) {
			PR_DestroyCondVar(jobp->join_cv);
			jobp->join_cv = NULL;
		}
		if (NULL != jobp->cancel_cv) {
			PR_DestroyCondVar(jobp->cancel_cv);
			jobp->cancel_cv = NULL;
		}
		PR_DELETE(jobp);
	}
}

static PRJob *
alloc_job(PRBool joinable, PRThreadPool *tp)
{
	PRJob *jobp;

	jobp = PR_NEWZAP(PRJob);
	if (NULL == jobp) 
		goto failed;
	if (joinable) {
		jobp->join_cv = PR_NewCondVar(tp->join_lock);
		jobp->join_wait = PR_TRUE;
		if (NULL == jobp->join_cv)
			goto failed;
	} else {
		jobp->join_cv = NULL;
	}
#ifdef OPT_WINNT
	jobp->nt_notifier.jobp = jobp;
#endif
	return jobp;
failed:
	delete_job(jobp);
	PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
	return NULL;
}

/* queue a job */
PR_IMPLEMENT(PRJob *)
PR_QueueJob(PRThreadPool *tpool, PRJobFn fn, void *arg, PRBool joinable)
{
	PRJob *jobp;

	jobp = alloc_job(joinable, tpool);
	if (NULL == jobp)
		return NULL;

	jobp->job_func = fn;
	jobp->job_arg = arg;
	jobp->tpool = tpool;

	add_to_jobq(tpool, jobp);
	return jobp;
}

/* queue a job, when a socket is readable or writeable */
static PRJob *
queue_io_job(PRThreadPool *tpool, PRJobIoDesc *iod, PRJobFn fn, void * arg,
				PRBool joinable, io_op_type op)
{
	PRJob *jobp;
	PRIntervalTime now;

	jobp = alloc_job(joinable, tpool);
	if (NULL == jobp) {
		return NULL;
	}

	/*
	 * Add a new job to io_jobq
	 * wakeup io worker thread
	 */

	jobp->job_func = fn;
	jobp->job_arg = arg;
	jobp->tpool = tpool;
	jobp->iod = iod;
	if (JOB_IO_READ == op) {
		jobp->io_op = JOB_IO_READ;
		jobp->io_poll_flags = PR_POLL_READ;
	} else if (JOB_IO_WRITE == op) {
		jobp->io_op = JOB_IO_WRITE;
		jobp->io_poll_flags = PR_POLL_WRITE;
	} else if (JOB_IO_ACCEPT == op) {
		jobp->io_op = JOB_IO_ACCEPT;
		jobp->io_poll_flags = PR_POLL_READ;
	} else if (JOB_IO_CONNECT == op) {
		jobp->io_op = JOB_IO_CONNECT;
		jobp->io_poll_flags = PR_POLL_WRITE|PR_POLL_EXCEPT;
	} else {
		delete_job(jobp);
		PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
		return NULL;
	}

	jobp->timeout = iod->timeout;
	if ((PR_INTERVAL_NO_TIMEOUT == iod->timeout) ||
			(PR_INTERVAL_NO_WAIT == iod->timeout)) {
		jobp->absolute = iod->timeout;
	} else {
		now = PR_IntervalNow();
		jobp->absolute = now + iod->timeout;
	}


	PR_Lock(tpool->ioq.lock);

	if (PR_CLIST_IS_EMPTY(&tpool->ioq.list) ||
			(PR_INTERVAL_NO_TIMEOUT == iod->timeout)) {
		PR_APPEND_LINK(&jobp->links,&tpool->ioq.list);
	} else if (PR_INTERVAL_NO_WAIT == iod->timeout) {
		PR_INSERT_LINK(&jobp->links,&tpool->ioq.list);
	} else {
		PRCList *qp;
		PRJob *tmp_jobp;
		/*
		 * insert into the timeout-sorted ioq
		 */
		for (qp = tpool->ioq.list.prev; qp != &tpool->ioq.list;
							qp = qp->prev) {
			tmp_jobp = JOB_LINKS_PTR(qp);
			if ((PRInt32)(jobp->absolute - tmp_jobp->absolute) >= 0) {
				break;
			}
		}
		PR_INSERT_AFTER(&jobp->links,qp);
	}

	jobp->on_ioq = PR_TRUE;
	tpool->ioq.cnt++;
	/*
	 * notify io worker thread(s)
	 */
	PR_Unlock(tpool->ioq.lock);
	notify_ioq(tpool);
	return jobp;
}

/* queue a job, when a socket is readable */
PR_IMPLEMENT(PRJob *)
PR_QueueJob_Read(PRThreadPool *tpool, PRJobIoDesc *iod, PRJobFn fn, void * arg,
											PRBool joinable)
{
	return (queue_io_job(tpool, iod, fn, arg, joinable, JOB_IO_READ));
}

/* queue a job, when a socket is writeable */
PR_IMPLEMENT(PRJob *)
PR_QueueJob_Write(PRThreadPool *tpool, PRJobIoDesc *iod, PRJobFn fn,void * arg,
										PRBool joinable)
{
	return (queue_io_job(tpool, iod, fn, arg, joinable, JOB_IO_WRITE));
}


/* queue a job, when a socket has a pending connection */
PR_IMPLEMENT(PRJob *)
PR_QueueJob_Accept(PRThreadPool *tpool, PRJobIoDesc *iod, PRJobFn fn,
								void * arg, PRBool joinable)
{
	return (queue_io_job(tpool, iod, fn, arg, joinable, JOB_IO_ACCEPT));
}

/* queue a job, when a socket can be connected */
PR_IMPLEMENT(PRJob *)
PR_QueueJob_Connect(PRThreadPool *tpool, PRJobIoDesc *iod,
			const PRNetAddr *addr, PRJobFn fn, void * arg, PRBool joinable)
{
	PRStatus rv;
	PRErrorCode err;

	rv = PR_Connect(iod->socket, addr, PR_INTERVAL_NO_WAIT);
	if ((rv == PR_FAILURE) && ((err = PR_GetError()) == PR_IN_PROGRESS_ERROR)){
		/* connection pending */
		return(queue_io_job(tpool, iod, fn, arg, joinable, JOB_IO_CONNECT));
	} else {
		/*
		 * connection succeeded or failed; add to jobq right away
		 */
		if (rv == PR_FAILURE)
			iod->error = err;
		else
			iod->error = 0;
		return(PR_QueueJob(tpool, fn, arg, joinable));
	}
}

/* queue a job, when a timer expires */
PR_IMPLEMENT(PRJob *)
PR_QueueJob_Timer(PRThreadPool *tpool, PRIntervalTime timeout,
							PRJobFn fn, void * arg, PRBool joinable)
{
	PRIntervalTime now;
	PRJob *jobp;

	if (PR_INTERVAL_NO_TIMEOUT == timeout) {
		PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
		return NULL;
	}
	if (PR_INTERVAL_NO_WAIT == timeout) {
		/*
		 * no waiting; add to jobq right away
		 */
		return(PR_QueueJob(tpool, fn, arg, joinable));
	}
	jobp = alloc_job(joinable, tpool);
	if (NULL == jobp) {
		return NULL;
	}

	/*
	 * Add a new job to timer_jobq
	 * wakeup timer worker thread
	 */

	jobp->job_func = fn;
	jobp->job_arg = arg;
	jobp->tpool = tpool;
	jobp->timeout = timeout;

	now = PR_IntervalNow();
	jobp->absolute = now + timeout;


	PR_Lock(tpool->timerq.lock);
	jobp->on_timerq = PR_TRUE;
	if (PR_CLIST_IS_EMPTY(&tpool->timerq.list))
		PR_APPEND_LINK(&jobp->links,&tpool->timerq.list);
	else {
		PRCList *qp;
		PRJob *tmp_jobp;
		/*
		 * insert into the sorted timer jobq
		 */
		for (qp = tpool->timerq.list.prev; qp != &tpool->timerq.list;
							qp = qp->prev) {
			tmp_jobp = JOB_LINKS_PTR(qp);
			if ((PRInt32)(jobp->absolute - tmp_jobp->absolute) >= 0) {
				break;
			}
		}
		PR_INSERT_AFTER(&jobp->links,qp);
	}
	tpool->timerq.cnt++;
	/*
	 * notify timer worker thread(s)
	 */
	notify_timerq(tpool);
	PR_Unlock(tpool->timerq.lock);
	return jobp;
}

static void
notify_timerq(PRThreadPool *tp)
{
	/*
	 * wakeup the timer thread(s)
	 */
	PR_NotifyCondVar(tp->timerq.cv);
}

static void
notify_ioq(PRThreadPool *tp)
{
PRStatus rval_status;

	/*
	 * wakeup the io thread(s)
	 */
	rval_status = PR_SetPollableEvent(tp->ioq.notify_fd);
	PR_ASSERT(PR_SUCCESS == rval_status);
}

/*
 * cancel a job
 *
 *	XXXX: is this needed? likely to be removed
 */
PR_IMPLEMENT(PRStatus)
PR_CancelJob(PRJob *jobp) {

	PRStatus rval = PR_FAILURE;
	PRThreadPool *tp;

	if (jobp->on_timerq) {
		/*
		 * now, check again while holding the timerq lock
		 */
		tp = jobp->tpool;
		PR_Lock(tp->timerq.lock);
		if (jobp->on_timerq) {
			jobp->on_timerq = PR_FALSE;
			PR_REMOVE_AND_INIT_LINK(&jobp->links);
			tp->timerq.cnt--;
			PR_Unlock(tp->timerq.lock);
			if (!JOINABLE_JOB(jobp)) {
				delete_job(jobp);
			} else {
				JOIN_NOTIFY(jobp);
			}
			rval = PR_SUCCESS;
		} else
			PR_Unlock(tp->timerq.lock);
	} else if (jobp->on_ioq) {
		/*
		 * now, check again while holding the ioq lock
		 */
		tp = jobp->tpool;
		PR_Lock(tp->ioq.lock);
		if (jobp->on_ioq) {
			jobp->cancel_cv = PR_NewCondVar(tp->ioq.lock);
			if (NULL == jobp->cancel_cv) {
				PR_Unlock(tp->ioq.lock);
				PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
				return PR_FAILURE;
			}
			/*
			 * mark job 'cancelled' and notify io thread(s)
			 * XXXX:
			 *		this assumes there is only one io thread; when there
			 * 		are multiple threads, the io thread processing this job
			 * 		must be notified.
			 */
			jobp->cancel_io = PR_TRUE;
			PR_Unlock(tp->ioq.lock);	/* release, reacquire ioq lock */
			notify_ioq(tp);
			PR_Lock(tp->ioq.lock);
			while (jobp->cancel_io)
				PR_WaitCondVar(jobp->cancel_cv, PR_INTERVAL_NO_TIMEOUT);
			PR_Unlock(tp->ioq.lock);
			PR_ASSERT(!jobp->on_ioq);
			if (!JOINABLE_JOB(jobp)) {
				delete_job(jobp);
			} else {
				JOIN_NOTIFY(jobp);
			}
			rval = PR_SUCCESS;
		} else
			PR_Unlock(tp->ioq.lock);
	}
	if (PR_FAILURE == rval)
		PR_SetError(PR_INVALID_STATE_ERROR, 0);
	return rval;
}

/* join a job, wait until completion */
PR_IMPLEMENT(PRStatus)
PR_JoinJob(PRJob *jobp)
{
	if (!JOINABLE_JOB(jobp)) {
		PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
		return PR_FAILURE;
	}
	PR_Lock(jobp->tpool->join_lock);
	while(jobp->join_wait)
		PR_WaitCondVar(jobp->join_cv, PR_INTERVAL_NO_TIMEOUT);
	PR_Unlock(jobp->tpool->join_lock);
	delete_job(jobp);
	return PR_SUCCESS;
}

/* shutdown threadpool */
PR_IMPLEMENT(PRStatus)
PR_ShutdownThreadPool(PRThreadPool *tpool)
{
PRStatus rval = PR_SUCCESS;

	PR_Lock(tpool->jobq.lock);
	tpool->shutdown = PR_TRUE;
	PR_NotifyAllCondVar(tpool->shutdown_cv);
	PR_Unlock(tpool->jobq.lock);

	return rval;
}

/*
 * join thread pool
 * 	wait for termination of worker threads
 *	reclaim threadpool resources
 */
PR_IMPLEMENT(PRStatus)
PR_JoinThreadPool(PRThreadPool *tpool)
{
PRStatus rval = PR_SUCCESS;
PRCList *head;
PRStatus rval_status;

	PR_Lock(tpool->jobq.lock);
	while (!tpool->shutdown)
		PR_WaitCondVar(tpool->shutdown_cv, PR_INTERVAL_NO_TIMEOUT);

	/*
	 * wakeup worker threads
	 */
#ifdef OPT_WINNT
	/*
	 * post shutdown notification for all threads
	 */
	{
		int i;
		for(i=0; i < tpool->current_threads; i++) {
			PostQueuedCompletionStatus(tpool->jobq.nt_completion_port, 0,
												TRUE, NULL);
		}
	}
#else
	PR_NotifyAllCondVar(tpool->jobq.cv);
#endif

	/*
	 * wakeup io thread(s)
	 */
	notify_ioq(tpool);

	/*
	 * wakeup timer thread(s)
	 */
	PR_Lock(tpool->timerq.lock);
	notify_timerq(tpool);
	PR_Unlock(tpool->timerq.lock);

	while (!PR_CLIST_IS_EMPTY(&tpool->jobq.wthreads)) {
		wthread *wthrp;

		head = PR_LIST_HEAD(&tpool->jobq.wthreads);
		PR_REMOVE_AND_INIT_LINK(head);
		PR_Unlock(tpool->jobq.lock);
		wthrp = WTHREAD_LINKS_PTR(head);
		rval_status = PR_JoinThread(wthrp->thread);
		PR_ASSERT(PR_SUCCESS == rval_status);
		PR_DELETE(wthrp);
		PR_Lock(tpool->jobq.lock);
	}
	PR_Unlock(tpool->jobq.lock);
	while (!PR_CLIST_IS_EMPTY(&tpool->ioq.wthreads)) {
		wthread *wthrp;

		head = PR_LIST_HEAD(&tpool->ioq.wthreads);
		PR_REMOVE_AND_INIT_LINK(head);
		wthrp = WTHREAD_LINKS_PTR(head);
		rval_status = PR_JoinThread(wthrp->thread);
		PR_ASSERT(PR_SUCCESS == rval_status);
		PR_DELETE(wthrp);
	}

	while (!PR_CLIST_IS_EMPTY(&tpool->timerq.wthreads)) {
		wthread *wthrp;

		head = PR_LIST_HEAD(&tpool->timerq.wthreads);
		PR_REMOVE_AND_INIT_LINK(head);
		wthrp = WTHREAD_LINKS_PTR(head);
		rval_status = PR_JoinThread(wthrp->thread);
		PR_ASSERT(PR_SUCCESS == rval_status);
		PR_DELETE(wthrp);
	}

	/*
	 * Delete queued jobs
	 */
	while (!PR_CLIST_IS_EMPTY(&tpool->jobq.list)) {
		PRJob *jobp;

		head = PR_LIST_HEAD(&tpool->jobq.list);
		PR_REMOVE_AND_INIT_LINK(head);
		jobp = JOB_LINKS_PTR(head);
		tpool->jobq.cnt--;
		delete_job(jobp);
	}

	/* delete io jobs */
	while (!PR_CLIST_IS_EMPTY(&tpool->ioq.list)) {
		PRJob *jobp;

		head = PR_LIST_HEAD(&tpool->ioq.list);
		PR_REMOVE_AND_INIT_LINK(head);
		tpool->ioq.cnt--;
		jobp = JOB_LINKS_PTR(head);
		delete_job(jobp);
	}

	/* delete timer jobs */
	while (!PR_CLIST_IS_EMPTY(&tpool->timerq.list)) {
		PRJob *jobp;

		head = PR_LIST_HEAD(&tpool->timerq.list);
		PR_REMOVE_AND_INIT_LINK(head);
		tpool->timerq.cnt--;
		jobp = JOB_LINKS_PTR(head);
		delete_job(jobp);
	}

	PR_ASSERT(0 == tpool->jobq.cnt);
	PR_ASSERT(0 == tpool->ioq.cnt);
	PR_ASSERT(0 == tpool->timerq.cnt);

	delete_threadpool(tpool);
	return rval;
}