/*
** Lock the lock.
*/
PR_IMPLEMENT(void) PR_Lock(PRLock *lock)
{
PRThread *me = _PR_MD_CURRENT_THREAD();
PRIntn is;
PRThread *t;
PRCList *q;
PR_ASSERT(me != suspendAllThread);
PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
PR_ASSERT(lock != NULL);
#ifdef _PR_GLOBAL_THREADS_ONLY
_PR_MD_LOCK(&lock->ilock);
PR_ASSERT(lock->owner == 0);
lock->owner = me;
return;
#else /* _PR_GLOBAL_THREADS_ONLY */
if (_native_threads_only) {
_PR_MD_LOCK(&lock->ilock);
PR_ASSERT(lock->owner == 0);
lock->owner = me;
return;
}
if (!_PR_IS_NATIVE_THREAD(me))
_PR_INTSOFF(is);
PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
retry:
_PR_LOCK_LOCK(lock);
if (lock->owner == 0) {
/* Just got the lock */
lock->owner = me;
lock->priority = me->priority;
/* Add the granted lock to this owning thread's lock list */
PR_APPEND_LINK(&lock->links, &me->lockList);
_PR_LOCK_UNLOCK(lock);
if (!_PR_IS_NATIVE_THREAD(me))
_PR_FAST_INTSON(is);
return;
}
/* If this thread already owns this lock, then it is a deadlock */
PR_ASSERT(lock->owner != me);
PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
#if 0
if (me->priority > lock->owner->priority) {
/*
** Give the lock owner a priority boost until we get the
** lock. Record the priority we boosted it to.
*/
lock->boostPriority = me->priority;
_PR_SetThreadPriority(lock->owner, me->priority);
}
#endif
/*
Add this thread to the asked for lock's list of waiting threads. We
add this thread thread in the right priority order so when the unlock
occurs, the thread with the higher priority will get the lock.
*/
q = lock->waitQ.next;
if (q == &lock->waitQ || _PR_THREAD_CONDQ_PTR(q)->priority ==
_PR_THREAD_CONDQ_PTR(lock->waitQ.prev)->priority) {
/*
* If all the threads in the lock waitQ have the same priority,
* then avoid scanning the list: insert the element at the end.
*/
q = &lock->waitQ;
} else {
/* Sort thread into lock's waitQ at appropriate point */
/* Now scan the list for where to insert this entry */
while (q != &lock->waitQ) {
t = _PR_THREAD_CONDQ_PTR(lock->waitQ.next);
if (me->priority > t->priority) {
/* Found a lower priority thread to insert in front of */
break;
}
q = q->next;
}
}
PR_INSERT_BEFORE(&me->waitQLinks, q);
/*
Now grab the threadLock since we are about to change the state. We have
to do this since a PR_Suspend or PR_SetThreadPriority type call that takes
a PRThread* as an argument could be changing the state of this thread from
a thread running on a different cpu.
*/
_PR_THREAD_LOCK(me);
me->state = _PR_LOCK_WAIT;
me->wait.lock = lock;
_PR_THREAD_UNLOCK(me);
_PR_LOCK_UNLOCK(lock);
_PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
goto retry;
#endif /* _PR_GLOBAL_THREADS_ONLY */
}
PR_IMPLEMENT(PRRecvWait*) PR_WaitRecvReady(PRWaitGroup *group)
{
PRCList *io_ready = NULL;
#ifdef WINNT
PRThread *me = _PR_MD_CURRENT_THREAD();
_MDOverlapped *overlapped;
#endif
if (!_pr_initialized) _PR_ImplicitInitialization();
if ((NULL == group) && (NULL == (group = MW_Init2()))) goto failed_init;
PR_Lock(group->ml);
if (_prmw_running != group->state)
{
PR_SetError(PR_INVALID_STATE_ERROR, 0);
goto invalid_state;
}
group->waiting_threads += 1; /* the polling thread is counted */
#ifdef WINNT
_PR_MD_LOCK(&group->mdlock);
while (PR_CLIST_IS_EMPTY(&group->io_ready))
{
_PR_THREAD_LOCK(me);
me->state = _PR_IO_WAIT;
PR_APPEND_LINK(&me->waitQLinks, &group->wait_list);
if (!_PR_IS_NATIVE_THREAD(me))
{
_PR_SLEEPQ_LOCK(me->cpu);
_PR_ADD_SLEEPQ(me, PR_INTERVAL_NO_TIMEOUT);
_PR_SLEEPQ_UNLOCK(me->cpu);
}
_PR_THREAD_UNLOCK(me);
_PR_MD_UNLOCK(&group->mdlock);
PR_Unlock(group->ml);
_PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
me->state = _PR_RUNNING;
PR_Lock(group->ml);
_PR_MD_LOCK(&group->mdlock);
if (_PR_PENDING_INTERRUPT(me)) {
PR_REMOVE_LINK(&me->waitQLinks);
_PR_MD_UNLOCK(&group->mdlock);
me->flags &= ~_PR_INTERRUPT;
me->io_suspended = PR_FALSE;
PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
goto aborted;
}
}
io_ready = PR_LIST_HEAD(&group->io_ready);
PR_ASSERT(io_ready != NULL);
PR_REMOVE_LINK(io_ready);
_PR_MD_UNLOCK(&group->mdlock);
overlapped = (_MDOverlapped *)
((char *)io_ready - offsetof(_MDOverlapped, data));
io_ready = &overlapped->data.mw.desc->internal;
#else
do
{
/*
** If the I/O ready list isn't empty, have this thread
** return with the first receive wait object that's available.
*/
if (PR_CLIST_IS_EMPTY(&group->io_ready))
{
/*
** Is there a polling thread yet? If not, grab this thread
** and use it.
*/
if (NULL == group->poller)
{
/*
** This thread will stay do polling until it becomes the only one
** left to service a completion. Then it will return and there will
** be none left to actually poll or to run completions.
**
** The polling function should only return w/ failure or
** with some I/O ready.
*/
if (PR_FAILURE == _MW_PollInternal(group)) goto failed_poll;
}
else
{
/*
** There are four reasons a thread can be awakened from
** a wait on the io_complete condition variable.
** 1. Some I/O has completed, i.e., the io_ready list
** is nonempty.
** 2. The wait group is canceled.
** 3. The thread is interrupted.
** 4. The current polling thread has to leave and needs
** a replacement.
** The logic to find a new polling thread is made more
** complicated by all the other possible events.
** I tried my best to write the logic clearly, but
** it is still full of if's with continue and goto.
*/
PRStatus st;
do
{
st = PR_WaitCondVar(group->io_complete, PR_INTERVAL_NO_TIMEOUT);
if (_prmw_running != group->state)
{
PR_SetError(PR_INVALID_STATE_ERROR, 0);
goto aborted;
}
if (_MW_ABORTED(st) || (NULL == group->poller)) break;
} while (PR_CLIST_IS_EMPTY(&group->io_ready));
/*
** The thread is interrupted and has to leave. It might
** have also been awakened to process ready i/o or be the
** new poller. To be safe, if either condition is true,
** we awaken another thread to take its place.
*/
if (_MW_ABORTED(st))
{
if ((NULL == group->poller
|| !PR_CLIST_IS_EMPTY(&group->io_ready))
&& group->waiting_threads > 1)
PR_NotifyCondVar(group->io_complete);
goto aborted;
}
/*
** A new poller is needed, but can I be the new poller?
** If there is no i/o ready, sure. But if there is any
** i/o ready, it has a higher priority. I want to
** process the ready i/o first and wake up another
** thread to be the new poller.
*/
if (NULL == group->poller)
{
if (PR_CLIST_IS_EMPTY(&group->io_ready))
continue;
if (group->waiting_threads > 1)
PR_NotifyCondVar(group->io_complete);
}
}
PR_ASSERT(!PR_CLIST_IS_EMPTY(&group->io_ready));
}
io_ready = PR_LIST_HEAD(&group->io_ready);
PR_NotifyCondVar(group->io_taken);
PR_ASSERT(io_ready != NULL);
PR_REMOVE_LINK(io_ready);
} while (NULL == io_ready);
failed_poll:
#endif
aborted:
group->waiting_threads -= 1;
invalid_state:
(void)MW_TestForShutdownInternal(group);
PR_Unlock(group->ml);
failed_init:
if (NULL != io_ready)
{
/* If the operation failed, record the reason why */
switch (((PRRecvWait*)io_ready)->outcome)
{
case PR_MW_PENDING:
PR_ASSERT(0);
break;
case PR_MW_SUCCESS:
#ifndef WINNT
_MW_InitialRecv(io_ready);
#endif
break;
#ifdef WINNT
case PR_MW_FAILURE:
_PR_MD_MAP_READ_ERROR(overlapped->data.mw.error);
break;
#endif
case PR_MW_TIMEOUT:
PR_SetError(PR_IO_TIMEOUT_ERROR, 0);
break;
case PR_MW_INTERRUPT:
PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
break;
default: break;
}
#ifdef WINNT
if (NULL != overlapped->data.mw.timer)
{
PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
!= overlapped->data.mw.desc->timeout);
CancelTimer(overlapped->data.mw.timer);
}
else
{
PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
== overlapped->data.mw.desc->timeout);
}
PR_DELETE(overlapped);
#endif
}
return (PRRecvWait*)io_ready;
} /* PR_WaitRecvReady */
/*
** 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 */
}
PR_IMPLEMENT(PRRecvWait*) PR_CancelWaitGroup(PRWaitGroup *group)
{
PRRecvWait **desc;
PRRecvWait *recv_wait = NULL;
#ifdef WINNT
_MDOverlapped *overlapped;
PRRecvWait **end;
PRThread *me = _PR_MD_CURRENT_THREAD();
#endif
if (NULL == group) group = mw_state->group;
PR_ASSERT(NULL != group);
if (NULL == group)
{
PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
return NULL;
}
PR_Lock(group->ml);
if (_prmw_stopped != group->state)
{
if (_prmw_running == group->state)
group->state = _prmw_stopping; /* so nothing new comes in */
if (0 == group->waiting_threads) /* is there anybody else? */
group->state = _prmw_stopped; /* we can stop right now */
else
{
PR_NotifyAllCondVar(group->new_business);
PR_NotifyAllCondVar(group->io_complete);
}
while (_prmw_stopped != group->state)
(void)PR_WaitCondVar(group->mw_manage, PR_INTERVAL_NO_TIMEOUT);
}
#ifdef WINNT
_PR_MD_LOCK(&group->mdlock);
#endif
/* make all the existing descriptors look done/interrupted */
#ifdef WINNT
end = &group->waiter->recv_wait + group->waiter->length;
for (desc = &group->waiter->recv_wait; desc < end; ++desc)
{
if (NULL != *desc)
{
if (InterlockedCompareExchange((LONG *)&(*desc)->outcome,
(LONG)PR_MW_INTERRUPT, (LONG)PR_MW_PENDING)
== (LONG)PR_MW_PENDING)
{
PRFileDesc *bottom = PR_GetIdentitiesLayer(
(*desc)->fd, PR_NSPR_IO_LAYER);
PR_ASSERT(NULL != bottom);
if (NULL == bottom)
{
PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
goto invalid_arg;
}
bottom->secret->state = _PR_FILEDESC_CLOSED;
#if 0
fprintf(stderr, "cancel wait group: closing socket\n");
#endif
if (closesocket(bottom->secret->md.osfd) == SOCKET_ERROR)
{
fprintf(stderr, "closesocket failed: %d\n",
WSAGetLastError());
exit(1);
}
}
}
}
while (group->waiter->count > 0)
{
_PR_THREAD_LOCK(me);
me->state = _PR_IO_WAIT;
PR_APPEND_LINK(&me->waitQLinks, &group->wait_list);
if (!_PR_IS_NATIVE_THREAD(me))
{
_PR_SLEEPQ_LOCK(me->cpu);
_PR_ADD_SLEEPQ(me, PR_INTERVAL_NO_TIMEOUT);
_PR_SLEEPQ_UNLOCK(me->cpu);
}
_PR_THREAD_UNLOCK(me);
_PR_MD_UNLOCK(&group->mdlock);
PR_Unlock(group->ml);
_PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
me->state = _PR_RUNNING;
PR_Lock(group->ml);
_PR_MD_LOCK(&group->mdlock);
}
#else
for (desc = &group->waiter->recv_wait; group->waiter->count > 0; ++desc)
{
PR_ASSERT(desc < &group->waiter->recv_wait + group->waiter->length);
if (NULL != *desc)
_MW_DoneInternal(group, desc, PR_MW_INTERRUPT);
}
#endif
/* take first element of finished list and return it or NULL */
if (PR_CLIST_IS_EMPTY(&group->io_ready))
PR_SetError(PR_GROUP_EMPTY_ERROR, 0);
else
{
PRCList *head = PR_LIST_HEAD(&group->io_ready);
PR_REMOVE_AND_INIT_LINK(head);
#ifdef WINNT
overlapped = (_MDOverlapped *)
((char *)head - offsetof(_MDOverlapped, data));
head = &overlapped->data.mw.desc->internal;
if (NULL != overlapped->data.mw.timer)
{
PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
!= overlapped->data.mw.desc->timeout);
CancelTimer(overlapped->data.mw.timer);
}
else
{
PR_ASSERT(PR_INTERVAL_NO_TIMEOUT
== overlapped->data.mw.desc->timeout);
}
PR_DELETE(overlapped);
#endif
recv_wait = (PRRecvWait*)head;
}
#ifdef WINNT
invalid_arg:
_PR_MD_UNLOCK(&group->mdlock);
#endif
PR_Unlock(group->ml);
return recv_wait;
} /* PR_CancelWaitGroup */
