/*
* 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;
}
/*
** Unblock the first runnable waiting thread. Skip over
** threads that are trying to be suspended
** Note: Caller must hold _PR_LOCK_LOCK()
*/
void _PR_UnblockLockWaiter(PRLock *lock)
{
PRThread *t = NULL;
PRThread *me;
PRCList *q;
q = lock->waitQ.next;
PR_ASSERT(q != &lock->waitQ);
while (q != &lock->waitQ) {
/* Unblock first waiter */
t = _PR_THREAD_CONDQ_PTR(q);
/*
** We are about to change the thread's state to runnable and for local
** threads, we are going to assign a cpu to it. So, protect thread's
** data structure.
*/
_PR_THREAD_LOCK(t);
if (t->flags & _PR_SUSPENDING) {
q = q->next;
_PR_THREAD_UNLOCK(t);
continue;
}
/* Found a runnable thread */
PR_ASSERT(t->state == _PR_LOCK_WAIT);
PR_ASSERT(t->wait.lock == lock);
t->wait.lock = 0;
PR_REMOVE_LINK(&t->waitQLinks); /* take it off lock's waitQ */
/*
** If this is a native thread, nothing else to do except to wake it
** up by calling the machine dependent wakeup routine.
**
** If this is a local thread, we need to assign it a cpu and
** put the thread on that cpu's run queue. There are two cases to
** take care of. If the currently running thread is also a local
** thread, we just assign our own cpu to that thread and put it on
** the cpu's run queue. If the the currently running thread is a
** native thread, we assign the primordial cpu to it (on NT,
** MD_WAKEUP handles the cpu assignment).
*/
if ( !_PR_IS_NATIVE_THREAD(t) ) {
t->state = _PR_RUNNABLE;
me = _PR_MD_CURRENT_THREAD();
_PR_AddThreadToRunQ(me, t);
_PR_THREAD_UNLOCK(t);
} else {
t->state = _PR_RUNNING;
_PR_THREAD_UNLOCK(t);
}
_PR_MD_WAKEUP_WAITER(t);
break;
}
return;
}
/*
** 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;
}
