int
pthread_mutex_unlock(pthread_mutex_t *mutexp)
{
pthread_t self = pthread_self();
struct pthread_mutex *mutex = (struct pthread_mutex *)*mutexp;
_rthread_debug(5, "%p: mutex_unlock %p\n", (void *)self,
(void *)mutex);
if (mutex == NULL)
#if PTHREAD_MUTEX_DEFAULT == PTHREAD_MUTEX_ERRORCHECK
return (EPERM);
#elif PTHREAD_MUTEX_DEFAULT == PTHREAD_MUTEX_NORMAL
return(0);
#else
abort();
#endif
if (mutex->owner != self) {
if (mutex->type == PTHREAD_MUTEX_ERRORCHECK ||
mutex->type == PTHREAD_MUTEX_RECURSIVE)
return (EPERM);
else {
/*
* For mutex type NORMAL our undefined behavior for
* unlocking an unlocked mutex is to succeed without
* error. All other undefined behaviors are to
* abort() immediately.
*/
if (mutex->owner == NULL &&
mutex->type == PTHREAD_MUTEX_NORMAL)
return (0);
else
abort();
}
}
if (--mutex->count == 0) {
pthread_t next;
_spinlock(&mutex->lock);
mutex->owner = next = TAILQ_FIRST(&mutex->lockers);
if (next != NULL)
TAILQ_REMOVE(&mutex->lockers, next, waiting);
_spinunlock(&mutex->lock);
if (next != NULL)
__thrwakeup(next, 1);
}
return (0);
}
/* always increment count */
int
_sem_post(sem_t sem)
{
int rv = 0;
_spinlock(&sem->lock);
sem->value++;
if (sem->waitcount) {
__thrwakeup(&sem->waitcount, 1);
rv = 1;
}
_spinunlock(&sem->lock);
return (rv);
}
int
pthread_cond_signal(pthread_cond_t *condp)
{
pthread_cond_t cond;
struct pthread_mutex *mutex;
pthread_t thread;
int wakeup;
/* uninitialized? Then there's obviously no one waiting! */
if (!*condp)
return 0;
cond = *condp;
_rthread_debug(5, "%p: cond_signal %p,%p\n", (void *)pthread_self(),
(void *)cond, (void *)cond->mutex);
_spinlock(&cond->lock);
thread = TAILQ_FIRST(&cond->waiters);
if (thread == NULL) {
assert(cond->mutex == NULL);
_spinunlock(&cond->lock);
return (0);
}
assert(thread->blocking_cond == cond);
TAILQ_REMOVE(&cond->waiters, thread, waiting);
thread->blocking_cond = NULL;
mutex = cond->mutex;
assert(mutex != NULL);
if (TAILQ_EMPTY(&cond->waiters))
cond->mutex = NULL;
/* link locks to prevent race with timedwait */
_spinlock(&mutex->lock);
_spinunlock(&cond->lock);
wakeup = mutex->owner == NULL && TAILQ_EMPTY(&mutex->lockers);
if (wakeup)
mutex->owner = thread;
else
TAILQ_INSERT_TAIL(&mutex->lockers, thread, waiting);
_spinunlock(&mutex->lock);
if (wakeup)
__thrwakeup(thread, 1);
return (0);
}
/* always increment count */
int
_sem_post(sem_t sem)
{
void *ident = (void *)&sem->waitcount;
int rv = 0;
if (sem->shared)
ident = SHARED_IDENT;
_spinlock(&sem->lock);
sem->value++;
if (sem->waitcount) {
__thrwakeup(ident, 1);
rv = 1;
}
_spinunlock(&sem->lock);
return (rv);
}
void
(funlockfile)(FILE * fp)
{
int idx = file_idx(fp);
struct file_lock *p;
/* Lock the hash table: */
_spinlock(&hash_lock);
/*
* Get a pointer to the lock for the file and check that
* the running thread is the one with the lock:
*/
if ((p = find_lock(idx, fp)) != NULL && p->owner == pthread_self()) {
/*
* Check if this thread has locked the FILE
* more than once:
*/
if (--p->count == 0) {
/* Get the new owner of the lock: */
if ((p->owner = TAILQ_FIRST(&p->lockers)) != NULL) {
/* Pop the thread off the queue: */
TAILQ_REMOVE(&p->lockers,p->owner,waiting);
/*
* This is the first lock for the new
* owner:
*/
p->count = 1;
__thrwakeup(p->owner, 1);
}
}
}
/* Unlock the hash table: */
_spinunlock(&hash_lock);
}
int
pthread_cond_broadcast(pthread_cond_t *condp)
{
pthread_cond_t cond;
struct pthread_mutex *mutex;
pthread_t thread;
pthread_t p;
int wakeup;
/* uninitialized? Then there's obviously no one waiting! */
if (!*condp)
return 0;
cond = *condp;
_rthread_debug(5, "%p: cond_broadcast %p,%p\n", (void *)pthread_self(),
(void *)cond, (void *)cond->mutex);
_spinlock(&cond->lock);
thread = TAILQ_FIRST(&cond->waiters);
if (thread == NULL) {
assert(cond->mutex == NULL);
_spinunlock(&cond->lock);
return (0);
}
mutex = cond->mutex;
assert(mutex != NULL);
/* walk the list, clearing the "blocked on condvar" pointer */
p = thread;
do
p->blocking_cond = NULL;
while ((p = TAILQ_NEXT(p, waiting)) != NULL);
/*
* We want to transfer all the threads from the condvar's list
* to the mutex's list. The TAILQ_* macros don't let us do that
* efficiently, so this is direct list surgery. Pay attention!
*/
/* 1) attach the first thread to the end of the mutex's list */
_spinlock(&mutex->lock);
wakeup = mutex->owner == NULL && TAILQ_EMPTY(&mutex->lockers);
thread->waiting.tqe_prev = mutex->lockers.tqh_last;
*(mutex->lockers.tqh_last) = thread;
/* 2) fix up the end pointer for the mutex's list */
mutex->lockers.tqh_last = cond->waiters.tqh_last;
if (wakeup) {
TAILQ_REMOVE(&mutex->lockers, thread, waiting);
mutex->owner = thread;
_spinunlock(&mutex->lock);
__thrwakeup(thread, 1);
} else
_spinunlock(&mutex->lock);
/* 3) reset the condvar's list and mutex pointer */
TAILQ_INIT(&cond->waiters);
assert(cond->mutex != NULL);
cond->mutex = NULL;
_spinunlock(&cond->lock);
return (0);
}
int
pthread_cond_wait(pthread_cond_t *condp, pthread_mutex_t *mutexp)
{
pthread_cond_t cond;
struct pthread_mutex *mutex = (struct pthread_mutex *)*mutexp;
struct tib *tib = TIB_GET();
pthread_t self = tib->tib_thread;
pthread_t next;
int mutex_count;
int canceled = 0;
int error;
PREP_CANCEL_POINT(tib);
if (!*condp)
if ((error = pthread_cond_init(condp, NULL)))
return (error);
cond = *condp;
_rthread_debug(5, "%p: cond_wait %p,%p\n", (void *)self,
(void *)cond, (void *)mutex);
if (mutex == NULL)
#if PTHREAD_MUTEX_DEFAULT == PTHREAD_MUTEX_ERRORCHECK
return (EPERM);
#else
abort();
#endif
if (mutex->owner != self) {
if (mutex->type == PTHREAD_MUTEX_ERRORCHECK)
return (EPERM);
else
abort();
}
ENTER_DELAYED_CANCEL_POINT(tib, self);
_spinlock(&cond->lock);
/* mark the condvar as being associated with this mutex */
if (cond->mutex == NULL) {
cond->mutex = mutex;
assert(TAILQ_EMPTY(&cond->waiters));
} else if (cond->mutex != mutex) {
assert(cond->mutex == mutex);
_spinunlock(&cond->lock);
LEAVE_CANCEL_POINT_INNER(tib, 1);
return (EINVAL);
} else
assert(! TAILQ_EMPTY(&cond->waiters));
/* snag the count in case this is a recursive mutex */
mutex_count = mutex->count;
/* transfer from the mutex queue to the condvar queue */
_spinlock(&mutex->lock);
self->blocking_cond = cond;
TAILQ_INSERT_TAIL(&cond->waiters, self, waiting);
_spinunlock(&cond->lock);
/* wake the next guy blocked on the mutex */
mutex->count = 0;
mutex->owner = next = TAILQ_FIRST(&mutex->lockers);
if (next != NULL) {
TAILQ_REMOVE(&mutex->lockers, next, waiting);
__thrwakeup(next, 1);
}
/* wait until we're the owner of the mutex again */
while (mutex->owner != self) {
error = __thrsleep(self, 0 | _USING_TICKETS, NULL,
&mutex->lock.ticket, &self->delayed_cancel);
/*
* If we took a normal signal (not from
* cancellation) then we should just go back to
* sleep without changing state (timeouts, etc).
*/
if (error == EINTR && (tib->tib_canceled == 0 ||
(tib->tib_cantcancel & CANCEL_DISABLED))) {
_spinlock(&mutex->lock);
continue;
}
/*
* The remaining reasons for waking up (normal
* wakeup and cancellation) all mean that we won't
* be staying in the condvar queue and we'll no
* longer be cancelable.
*/
LEAVE_CANCEL_POINT_INNER(tib, 0);
/*
* If we're no longer in the condvar's queue then
* we're just waiting for mutex ownership. Need
* cond->lock here to prevent race with cond_signal().
*/
_spinlock(&cond->lock);
if (self->blocking_cond == NULL) {
_spinunlock(&cond->lock);
_spinlock(&mutex->lock);
continue;
}
assert(self->blocking_cond == cond);
/* if canceled, make note of that */
if (error == EINTR)
canceled = 1;
/* transfer between the queues */
TAILQ_REMOVE(&cond->waiters, self, waiting);
assert(mutex == cond->mutex);
if (TAILQ_EMPTY(&cond->waiters))
cond->mutex = NULL;
self->blocking_cond = NULL;
_spinunlock(&cond->lock);
_spinlock(&mutex->lock);
/* mutex unlocked right now? */
if (mutex->owner == NULL &&
TAILQ_EMPTY(&mutex->lockers)) {
assert(mutex->count == 0);
mutex->owner = self;
break;
}
TAILQ_INSERT_TAIL(&mutex->lockers, self, waiting);
}
/* restore the mutex's count */
mutex->count = mutex_count;
_spinunlock(&mutex->lock);
LEAVE_CANCEL_POINT_INNER(tib, canceled);
return (0);
}
int
pthread_cond_timedwait(pthread_cond_t *condp, pthread_mutex_t *mutexp,
const struct timespec *abstime)
{
pthread_cond_t cond;
struct pthread_mutex *mutex = (struct pthread_mutex *)*mutexp;
pthread_t self = pthread_self();
pthread_t next;
int mutex_count;
int canceled = 0;
int rv = 0;
int error;
if (!*condp)
if ((error = pthread_cond_init(condp, NULL)))
return (error);
cond = *condp;
_rthread_debug(5, "%p: cond_timed %p,%p\n", (void *)self,
(void *)cond, (void *)mutex);
if (mutex == NULL)
#if PTHREAD_MUTEX_DEFAULT == PTHREAD_MUTEX_ERRORCHECK
return (EPERM);
#else
abort();
#endif
if (mutex->owner != self) {
if (mutex->type == PTHREAD_MUTEX_ERRORCHECK)
return (EPERM);
else
abort();
}
if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
abstime->tv_nsec >= 1000000000)
return (EINVAL);
_enter_delayed_cancel(self);
_spinlock(&cond->lock);
/* mark the condvar as being associated with this mutex */
if (cond->mutex == NULL) {
cond->mutex = mutex;
assert(TAILQ_EMPTY(&cond->waiters));
} else if (cond->mutex != mutex) {
assert(cond->mutex == mutex);
_spinunlock(&cond->lock);
_leave_delayed_cancel(self, 1);
return (EINVAL);
} else
assert(! TAILQ_EMPTY(&cond->waiters));
/* snag the count in case this is a recursive mutex */
mutex_count = mutex->count;
/* transfer from the mutex queue to the condvar queue */
_spinlock(&mutex->lock);
self->blocking_cond = cond;
TAILQ_INSERT_TAIL(&cond->waiters, self, waiting);
_spinunlock(&cond->lock);
/* wake the next guy blocked on the mutex */
mutex->count = 0;
mutex->owner = next = TAILQ_FIRST(&mutex->lockers);
if (next != NULL) {
TAILQ_REMOVE(&mutex->lockers, next, waiting);
__thrwakeup(next, 1);
}
/* wait until we're the owner of the mutex again */
while (mutex->owner != self) {
error = __thrsleep(self, cond->clock | _USING_TICKETS, abstime,
&mutex->lock.ticket, &self->delayed_cancel);
/*
* If abstime == NULL, then we're definitely waiting
* on the mutex instead of the condvar, and are
* just waiting for mutex ownership, regardless of
* why we woke up.
*/
if (abstime == NULL) {
_spinlock(&mutex->lock);
continue;
}
/*
* If we took a normal signal (not from
* cancellation) then we should just go back to
* sleep without changing state (timeouts, etc).
*/
if (error == EINTR && !IS_CANCELED(self)) {
_spinlock(&mutex->lock);
continue;
}
/*
* The remaining reasons for waking up (normal
* wakeup, timeout, and cancellation) all mean that
* we won't be staying in the condvar queue and
* we'll no longer time out or be cancelable.
*/
abstime = NULL;
_leave_delayed_cancel(self, 0);
/*
* If we're no longer in the condvar's queue then
* we're just waiting for mutex ownership. Need
* cond->lock here to prevent race with cond_signal().
*/
_spinlock(&cond->lock);
if (self->blocking_cond == NULL) {
_spinunlock(&cond->lock);
_spinlock(&mutex->lock);
continue;
}
assert(self->blocking_cond == cond);
/* if timeout or canceled, make note of that */
if (error == EWOULDBLOCK)
rv = ETIMEDOUT;
else if (error == EINTR)
canceled = 1;
/* transfer between the queues */
TAILQ_REMOVE(&cond->waiters, self, waiting);
assert(mutex == cond->mutex);
if (TAILQ_EMPTY(&cond->waiters))
cond->mutex = NULL;
self->blocking_cond = NULL;
_spinunlock(&cond->lock);
_spinlock(&mutex->lock);
/* mutex unlocked right now? */
if (mutex->owner == NULL &&
TAILQ_EMPTY(&mutex->lockers)) {
assert(mutex->count == 0);
mutex->owner = self;
break;
}
TAILQ_INSERT_TAIL(&mutex->lockers, self, waiting);
}
/* restore the mutex's count */
mutex->count = mutex_count;
_spinunlock(&mutex->lock);
_leave_delayed_cancel(self, canceled);
return (rv);
}
