/*
* Internal implementation of semaphores
*/
int
_sem_wait(sem_t sem, int tryonly, const struct timespec *abstime,
int *delayed_cancel)
{
void *ident = (void *)&sem->waitcount;
int r;
if (sem->shared)
ident = SHARED_IDENT;
_spinlock(&sem->lock);
if (sem->value) {
sem->value--;
r = 0;
} else if (tryonly) {
r = EAGAIN;
} else {
sem->waitcount++;
do {
r = __thrsleep(ident, CLOCK_REALTIME |
_USING_TICKETS, abstime, &sem->lock.ticket,
delayed_cancel);
_spinlock(&sem->lock);
/* ignore interruptions other than cancelation */
if (r == EINTR && (delayed_cancel == NULL ||
*delayed_cancel == 0))
r = 0;
} while (r == 0 && sem->value == 0);
sem->waitcount--;
if (r == 0)
sem->value--;
}
_spinunlock(&sem->lock);
return (r);
}
/*
* Internal implementation of semaphores
*/
int
_sem_wait(sem_t sem, int tryonly, const struct timespec *abstime,
int *delayed_cancel)
{
int r;
_spinlock(&sem->lock);
if (sem->value) {
sem->value--;
r = 0;
} else if (tryonly) {
r = EAGAIN;
} else {
sem->waitcount++;
do {
r = __thrsleep(&sem->waitcount, CLOCK_REALTIME,
abstime, &sem->lock, delayed_cancel);
_spinlock(&sem->lock);
/* ignore interruptions other than cancelation */
if (r == EINTR && (delayed_cancel == NULL ||
*delayed_cancel == 0))
r = 0;
} while (r == 0 && sem->value == 0);
sem->waitcount--;
if (r == 0)
sem->value--;
}
_spinunlock(&sem->lock);
return (r);
}
void
(flockfile)(FILE * fp)
{
int idx = file_idx(fp);
struct file_lock *p;
pthread_t self = pthread_self();
/* Lock the hash table: */
_spinlock(&hash_lock);
/* Get a pointer to any existing lock for the file: */
if ((p = find_lock(idx, fp)) == NULL) {
/*
* The file is not locked, so this thread can
* grab the lock:
*/
do_lock(idx, fp);
/*
* The file is already locked, so check if the
* running thread is the owner:
*/
} else if (p->owner == self) {
/*
* The running thread is already the
* owner, so increment the count of
* the number of times it has locked
* the file:
*/
p->count++;
} else {
/*
* The file is locked for another thread.
* Append this thread to the queue of
* threads waiting on the lock.
*/
TAILQ_INSERT_TAIL(&p->lockers,self,waiting);
while (p->owner != self) {
__thrsleep(self, 0 | _USING_TICKETS, NULL,
&hash_lock.ticket, NULL);
_spinlock(&hash_lock);
}
}
/* Unlock the hash table: */
_spinunlock(&hash_lock);
}
static int
_rthread_mutex_lock(pthread_mutex_t *mutexp, int trywait,
const struct timespec *abstime)
{
struct pthread_mutex *mutex;
pthread_t self = pthread_self();
int ret = 0;
/*
* If the mutex is statically initialized, perform the dynamic
* initialization. Note: _thread_mutex_lock() in libc requires
* _rthread_mutex_lock() to perform the mutex init when *mutexp
* is NULL.
*/
if (*mutexp == NULL) {
_spinlock(&static_init_lock);
if (*mutexp == NULL)
ret = pthread_mutex_init(mutexp, NULL);
_spinunlock(&static_init_lock);
if (ret != 0)
return (EINVAL);
}
mutex = (struct pthread_mutex *)*mutexp;
_rthread_debug(5, "%p: mutex_lock %p\n", (void *)self, (void *)mutex);
_spinlock(&mutex->lock);
if (mutex->owner == NULL && TAILQ_EMPTY(&mutex->lockers)) {
assert(mutex->count == 0);
mutex->owner = self;
} else if (mutex->owner == self) {
assert(mutex->count > 0);
/* already owner? handle recursive behavior */
if (mutex->type != PTHREAD_MUTEX_RECURSIVE)
{
if (trywait ||
mutex->type == PTHREAD_MUTEX_ERRORCHECK) {
_spinunlock(&mutex->lock);
return (trywait ? EBUSY : EDEADLK);
}
/* self-deadlock is disallowed by strict */
if (mutex->type == PTHREAD_MUTEX_STRICT_NP &&
abstime == NULL)
abort();
/* self-deadlock, possibly until timeout */
while (__thrsleep(self, CLOCK_REALTIME |
_USING_TICKETS, abstime,
&mutex->lock.ticket, NULL) != EWOULDBLOCK)
_spinlock(&mutex->lock);
return (ETIMEDOUT);
}
if (mutex->count == INT_MAX) {
_spinunlock(&mutex->lock);
return (EAGAIN);
}
} else if (trywait) {
/* try failed */
_spinunlock(&mutex->lock);
return (EBUSY);
} else {
/* add to the wait queue and block until at the head */
TAILQ_INSERT_TAIL(&mutex->lockers, self, waiting);
while (mutex->owner != self) {
ret = __thrsleep(self, CLOCK_REALTIME | _USING_TICKETS,
abstime, &mutex->lock.ticket, NULL);
_spinlock(&mutex->lock);
assert(mutex->owner != NULL);
if (ret == EWOULDBLOCK) {
if (mutex->owner == self)
break;
TAILQ_REMOVE(&mutex->lockers, self, waiting);
_spinunlock(&mutex->lock);
return (ETIMEDOUT);
}
}
}
mutex->count++;
_spinunlock(&mutex->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);
}
