static int _rthread_init(void) { pthread_t thread = &_initial_thread; extern int __isthreaded; thread->tid = getthrid(); thread->donesem.lock = _SPINLOCK_UNLOCKED; thread->flags |= THREAD_CANCEL_ENABLE|THREAD_CANCEL_DEFERRED; thread->flags_lock = _SPINLOCK_UNLOCKED; strlcpy(thread->name, "Main process", sizeof(thread->name)); LIST_INSERT_HEAD(&_thread_list, thread, threads); if (_rthread_open_kqueue()) return (errno); _rthread_debug_init(); _rthread_debug(1, "rthread init\n"); _threads_ready = 1; __isthreaded = 1; #if defined(__ELF__) && defined(PIC) /* * To avoid recursion problems in ld.so, we need to trigger the * functions once to fully bind them before registering them * for use. */ _rthread_dl_lock(0); _rthread_dl_lock(1); _rthread_bind_lock(0); _rthread_bind_lock(1); dlctl(NULL, DL_SETTHREADLCK, _rthread_dl_lock); dlctl(NULL, DL_SETBINDLCK, _rthread_bind_lock); #endif return (0); }
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); }
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); }
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_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); }