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;
}

/*
** 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;

    PR_ASSERT(lock != NULL);

    cvar = PR_NEWZAP(PRCondVar);
    if (cvar) {
#ifdef _PR_GLOBAL_THREADS_ONLY
	if(_PR_MD_NEW_CV(&cvar->md)) {
		PR_DELETE(cvar);
		PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
		return NULL;
	}
#endif
        if (_PR_MD_NEW_LOCK(&(cvar->ilock)) == PR_FAILURE) {
		PR_DELETE(cvar);
		PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
		return NULL;
	}
    cvar->lock = lock;
	PR_INIT_CLIST(&cvar->condQ);

    } else {
        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    }
    return cvar;
}

/*
 * 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 md_PostNotifyToCvar(_MDCVar *cvar, _MDLock *lock,
        PRBool broadcast)
{
    PRIntn index = 0;
    _MDNotified *notified = &lock->notified;

    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;
            }
        }
        /* if not full, enter new CV in this array */
        if (notified->length < _MD_CV_NOTIFIED_LENGTH) break;

        /* if there's no link, create an empty array and link it */
        if (NULL == notified->link) {
            notified->link = PR_NEWZAP(_MDNotified);
        }

        notified = notified->link;
    }

    /* A brand new entry in the array */
    notified->cv[index].times = (broadcast) ? -1 : 1;
    notified->cv[index].cv = cvar;
    notified->length += 1;
}

PR_IMPLEMENT(PRAlarmID*) PR_SetAlarm(
    PRAlarm *alarm, PRIntervalTime period, PRUint32 rate,
    PRPeriodicAlarmFn function, void *clientData)
{
    /*
     * Create a new periodic alarm an existing current structure.
     * Set up the context and compute the first notify time (immediate).
     * Link the new ID into the head of the list (since it's notifying
     * immediately).
     */

    PRAlarmID *id = PR_NEWZAP(PRAlarmID);

    if (!id)
        return NULL;

    id->alarm = alarm;
    PR_INIT_CLIST(&id->list);
    id->function = function;
    id->clientData = clientData;
    id->period = period;
    id->rate = rate;
    id->epoch = id->nextNotify = PR_IntervalNow();
    (void)pr_PredictNextNotifyTime(id);

    PR_Lock(alarm->lock);
    PR_INSERT_BEFORE(&id->list, &alarm->timers);
    PR_NotifyCondVar(alarm->cond);
    PR_Unlock(alarm->lock);

    return id;
}  /* PR_SetAlarm */

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;
}

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;
}

/*
** Create a new monitor.
*/
PR_IMPLEMENT(PRMonitor*) PR_NewMonitor()
{
    PRMonitor *mon;
	PRCondVar *cvar;
	PRLock *lock;

    mon = PR_NEWZAP(PRMonitor);
    if (mon) {
		lock = PR_NewLock();
	    if (!lock) {
			PR_DELETE(mon);
			return 0;
    	}

	    cvar = PR_NewCondVar(lock);
	    if (!cvar) {
	    	PR_DestroyLock(lock);
			PR_DELETE(mon);
			return 0;
    	}
    	mon->cvar = cvar;
	mon->name = NULL;
    }
    return mon;
}

/*
** Create a new semaphore.
*/
PR_IMPLEMENT(PRSemaphore*) PR_NewSem(PRUintn value)
{
    PRSemaphore *sem;
    PRCondVar *cvar;
    PRLock *lock;

    sem = PR_NEWZAP(PRSemaphore);
    if (sem) {
#ifdef HAVE_CVAR_BUILT_ON_SEM
        _PR_MD_NEW_SEM(&sem->md, value);
#else
        lock = PR_NewLock();
        if (!lock) {
            PR_DELETE(sem);
            return NULL;
    	}

        cvar = PR_NewCondVar(lock);
        if (!cvar) {
            PR_DestroyLock(lock);
            PR_DELETE(sem);
            return NULL;
    	}
    	sem->cvar = cvar;
    	sem->count = value;
#endif
    }
    return sem;
}

static PRFileDesc *PushLayer(PRFileDesc *stack)
{
    PRStatus rv;
    PRFileDesc *layer = PR_CreateIOLayerStub(identity, &myMethods);
    layer->secret = PR_NEWZAP(PRFilePrivate);
    rv = PR_PushIOLayer(stack, PR_GetLayersIdentity(stack), layer);
    PR_ASSERT(PR_SUCCESS == rv);
    if (verbosity > quiet)
        PR_fprintf(logFile, "Pushed layer(0x%x) onto stack(0x%x)\n", layer, stack);
    return stack;
}  /* PushLayer */

PR_IMPLEMENT(PRMWaitEnumerator*) PR_CreateMWaitEnumerator(PRWaitGroup *group)
{
    PRMWaitEnumerator *enumerator = PR_NEWZAP(PRMWaitEnumerator);
    if (NULL == enumerator) PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    else
    {
        enumerator->group = group;
        enumerator->seal = _PR_ENUM_SEALED;
    }
    return enumerator;
}  /* PR_CreateMWaitEnumerator */

/*
 * add a job to the work queue
 */
static void
add_to_jobq(PRThreadPool *tp, PRJob *jobp)
{
	/*
	 * add to jobq
	 */
#ifdef OPT_WINNT
	PR_Lock(tp->jobq.lock);
	tp->jobq.cnt++;
	PR_Unlock(tp->jobq.lock);
	/*
	 * notify worker thread(s)
	 */
	PostQueuedCompletionStatus(tp->jobq.nt_completion_port, 0,
            FALSE, &jobp->nt_notifier.overlapped);
#else
	PR_Lock(tp->jobq.lock);
	PR_APPEND_LINK(&jobp->links,&tp->jobq.list);
	tp->jobq.cnt++;
	if ((tp->idle_threads < tp->jobq.cnt) &&
					(tp->current_threads < tp->max_threads)) {
		wthread *wthrp;
		/*
		 * increment thread count and unlock the jobq lock
		 */
		tp->current_threads++;
		PR_Unlock(tp->jobq.lock);
		/* create new worker thread */
		wthrp = PR_NEWZAP(wthread);
		if (wthrp) {
			wthrp->thread = PR_CreateThread(PR_USER_THREAD, wstart,
						tp, PR_PRIORITY_NORMAL,
						PR_GLOBAL_THREAD,PR_JOINABLE_THREAD,tp->stacksize);
			if (NULL == wthrp->thread) {
				PR_DELETE(wthrp);  /* this sets wthrp to NULL */
			}
		}
		PR_Lock(tp->jobq.lock);
		if (NULL == wthrp) {
			tp->current_threads--;
		} else {
			PR_APPEND_LINK(&wthrp->links, &tp->jobq.wthreads);
		}
	}
	/*
	 * wakeup a worker thread
	 */
	PR_NotifyCondVar(tp->jobq.cv);
	PR_Unlock(tp->jobq.lock);
#endif
}

SECCipherFind *sec_CipherFindInit(PRBool onlyAllowed,
				  secCPStruct *policy,
				  long *ciphers)
{
  SECCipherFind *find = PR_NEWZAP(SECCipherFind);
  if (find)
    {
      find->policy = policy;
      find->ciphers = ciphers;
      find->onlyAllowed = onlyAllowed;
      find->index = -1;
    }
  return find;
}

PR_IMPLEMENT(PRMonitor*) PR_NewMonitor(void)
{
    PRMonitor *mon;
    PRCondVar *cvar;

    if (!_pr_initialized) _PR_ImplicitInitialization();

    cvar = PR_NEWZAP(PRCondVar);
    if (NULL == cvar)
    {
        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
        return NULL;
    }
    mon = PR_NEWZAP(PRMonitor);
    if (mon != NULL)
    {
        int rv;
        rv = _PT_PTHREAD_MUTEX_INIT(mon->lock.mutex, _pt_mattr); 
        PR_ASSERT(0 == rv);

        _PT_PTHREAD_INVALIDATE_THR_HANDLE(mon->owner);

        mon->cvar = cvar;
        rv = _PT_PTHREAD_COND_INIT(mon->cvar->cv, _pt_cvar_attr); 
        PR_ASSERT(0 == rv);
        mon->entryCount = 0;
        mon->cvar->lock = &mon->lock;
        if (0 != rv)
        {
            PR_DELETE(mon);
            PR_DELETE(cvar);
            mon = NULL;
        }
    }
    return mon;
}  /* PR_NewMonitor */

PR_IMPLEMENT(PRLock*) PR_NewLock(void)
{
    PRLock *lock;

    if (!_pr_initialized) _PR_ImplicitInitialization();

    lock = PR_NEWZAP(PRLock);
    if (lock) {
        if (_PR_InitLock(lock) != PR_SUCCESS) {
            PR_DELETE(lock);
            return NULL;
        }
    }
    return lock;
}

    PR_NewSem (PRUintn value)
{
	PRSemaphore *semaphore;

	if (!_pr_initialized) _PR_ImplicitInitialization();

	semaphore = PR_NEWZAP(PRSemaphore);
	if (NULL != semaphore) {
		if ((semaphore->sem = create_sem(value, "nspr_sem")) < B_NO_ERROR)
			return NULL;
		else 
			return semaphore;
	}
	return NULL;
}

PR_IMPLEMENT(PRLogModuleInfo*) PR_NewLogModule(const char *name)
{
    PRLogModuleInfo *lm;

        if (!_pr_initialized) _PR_ImplicitInitialization();

    lm = PR_NEWZAP(PRLogModuleInfo);
    if (lm) {
        lm->name = strdup(name);
        lm->level = PR_LOG_NONE;
        lm->next = logModules;
        logModules = lm;
        _PR_SetLogModuleLevel(lm);
    }
    return lm;
}

void _PR_InitMW(void)
{
#ifdef WINNT
    /*
     * We use NT 4's InterlockedCompareExchange() to operate
     * on PRMWStatus variables.
     */
    PR_ASSERT(sizeof(LONG) == sizeof(PRMWStatus));
    TimerInit();
#endif
    mw_lock = PR_NewLock();
    PR_ASSERT(NULL != mw_lock);
    mw_state = PR_NEWZAP(_PRGlobalState);
    PR_ASSERT(NULL != mw_state);
    PR_INIT_CLIST(&mw_state->group_list);
    max_polling_interval = PR_MillisecondsToInterval(MAX_POLLING_INTERVAL);
}  /* _PR_InitMW */

PR_IMPLEMENT(PRStatus) PR_RegisterRootFinder(
    GCRootFinder f, char *name, void *arg)
{
    RootFinder *rf = PR_NEWZAP(RootFinder);
    if (rf) {
	    rf->func = f;
	    rf->name = name;
	    rf->arg = arg;

	    LOCK_GC();
	    rf->next = _pr_rootFinders;
	    _pr_rootFinders = rf;
	    UNLOCK_GC();
	    return PR_SUCCESS;
    }
    return PR_FAILURE;
}

PR_IMPLEMENT(PLOptState*) PL_CreateLongOptState(
    PRIntn argc, char **argv, const char *options,
    const PLLongOpt *longOpts)
{
    PLOptState *opt = NULL;
    PLOptionInternal *internal;

    if (NULL == options)
    {
        PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
        return opt;
    }

    opt = PR_NEWZAP(PLOptState);
    if (NULL == opt)
    {
        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
        return opt;
    }

    internal = PR_NEW(PLOptionInternal);
    if (NULL == internal)
    {
        PR_DELETE(opt);
        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
        return NULL;
    }

    opt->option = 0;
    opt->value = NULL;
    opt->internal = internal;
    opt->longOption   =  0;
    opt->longOptIndex = -1;

    internal->argc = argc;
    internal->argv = argv;
    internal->xargc = 0;
    internal->xargv = &static_Nul;
    internal->minus = 0;
    internal->options = options;
    internal->longOpts = longOpts;
    internal->endOfOpts = PR_FALSE;
    internal->optionsLen = PL_strlen(options);

    return opt;
}  /* PL_CreateLongOptState */

PR_IMPLEMENT(PRLock*) PR_NewLock(void)
{
    PRLock *lock;

    if (!_pr_initialized) _PR_ImplicitInitialization();

    lock = PR_NEWZAP(PRLock);
    if (lock) {
        if (_PR_MD_NEW_LOCK(&lock->ilock) == PR_FAILURE) {
		PR_DELETE(lock);
		return(NULL);
	}
        PR_INIT_CLIST(&lock->links);
        PR_INIT_CLIST(&lock->waitQ);
    }
    return lock;
}