/* Get current value of timer TIMERID and store it in VLAUE. */ int timer_gettime (timer_t timerid, struct itimerspec *value) { struct timer_node *timer; struct timespec now, expiry; int retval = -1, armed = 0, valid; clock_t clock = 0; pthread_mutex_lock (&__timer_mutex); timer = timer_id2ptr (timerid); valid = timer_valid (timer); if (valid) { armed = timer->armed; expiry = timer->expirytime; clock = timer->clock; value->it_interval = timer->value.it_interval; } pthread_mutex_unlock (&__timer_mutex); if (valid) { if (armed) { clock_gettime (clock, &now); if (timespec_compare (&now, &expiry) < 0) timespec_sub (&value->it_value, &expiry, &now); else { value->it_value.tv_sec = 0; value->it_value.tv_nsec = 0; } } else { value->it_value.tv_sec = 0; value->it_value.tv_nsec = 0; } retval = 0; } else __set_errno (EINVAL); return retval; }
/* Get expiration overrun for timer TIMERID. */ int timer_getoverrun (timer_t timerid) { struct timer_node *timer; int retval = -1; pthread_mutex_lock (&__timer_mutex); if (! timer_valid (timer = timer_id2ptr (timerid))) __set_errno (EINVAL); else retval = timer->overrun_count; pthread_mutex_unlock (&__timer_mutex); return retval; }
/* Delete timer TIMERID. */ int timer_delete ( timer_t timerid) { struct timer_node *timer; int retval = -1; pthread_mutex_lock (&__timer_mutex); timer = timer_id2ptr (timerid); if (! timer_valid (timer)) /* Invalid timer ID or the timer is not in use. */ __set_errno (EINVAL); else { if (timer->armed && timer->thread != NULL) { struct thread_node *thread = timer->thread; assert (thread != NULL); /* If thread is cancelled while waiting for handler to terminate, the mutex is unlocked and timer_delete is aborted. */ pthread_cleanup_push (__timer_mutex_cancel_handler, &__timer_mutex); /* If timer is currently being serviced, wait for it to finish. */ while (thread->current_timer == timer) pthread_cond_wait (&thread->cond, &__timer_mutex); pthread_cleanup_pop (0); } /* Remove timer from whatever queue it may be on and deallocate it. */ timer->inuse = TIMER_DELETED; list_unlink_ip (&timer->links); timer_delref (timer); retval = 0; } pthread_mutex_unlock (&__timer_mutex); return retval; }
/* Set timer TIMERID to VALUE, returning old value in OVLAUE. */ int timer_settime (timer_t timerid, int flags, const struct itimerspec *value, struct itimerspec *ovalue) { struct timer_node *timer; struct thread_node *thread = NULL; struct timespec now; int have_now = 0, need_wakeup = 0; int retval = -1; timer = timer_id2ptr (timerid); if (timer == NULL) { __set_errno (EINVAL); goto bail; } if (value->it_interval.tv_nsec < 0 || value->it_interval.tv_nsec >= 1000000000 || value->it_value.tv_nsec < 0 || value->it_value.tv_nsec >= 1000000000) { __set_errno (EINVAL); goto bail; } /* Will need to know current time since this is a relative timer; might as well make the system call outside of the lock now! */ if ((flags & TIMER_ABSTIME) == 0) { clock_gettime (timer->clock, &now); have_now = 1; } pthread_mutex_lock (&__timer_mutex); timer_addref (timer); /* One final check of timer validity; this one is possible only until we have the mutex, because it accesses the inuse flag. */ if (! timer_valid(timer)) { __set_errno (EINVAL); goto unlock_bail; } if (ovalue != NULL) { ovalue->it_interval = timer->value.it_interval; if (timer->armed) { if (! have_now) { pthread_mutex_unlock (&__timer_mutex); clock_gettime (timer->clock, &now); have_now = 1; pthread_mutex_lock (&__timer_mutex); timer_addref (timer); } timespec_sub (&ovalue->it_value, &timer->expirytime, &now); } else { ovalue->it_value.tv_sec = 0; ovalue->it_value.tv_nsec = 0; } } timer->value = *value; list_unlink_ip (&timer->links); timer->armed = 0; thread = timer->thread; /* A value of { 0, 0 } causes the timer to be stopped. */ if (value->it_value.tv_sec != 0 || __builtin_expect (value->it_value.tv_nsec != 0, 1)) { if ((flags & TIMER_ABSTIME) != 0) /* The user specified the expiration time. */ timer->expirytime = value->it_value; else timespec_add (&timer->expirytime, &now, &value->it_value); /* Only need to wake up the thread if timer is inserted at the head of the queue. */ if (thread != NULL) need_wakeup = __timer_thread_queue_timer (thread, timer); timer->armed = 1; } retval = 0; unlock_bail: timer_delref (timer); pthread_mutex_unlock (&__timer_mutex); bail: if (thread != NULL && need_wakeup) __timer_thread_wakeup (thread); return retval; }