Example #1
0
/* 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;
}
Example #2
0
/* Create new per-process timer using CLOCK.  */
int
timer_create (
     clockid_t clock_id,
     struct sigevent *evp,
     timer_t *timerid)
{
  int retval = -1;
  struct timer_node *newtimer = NULL;
  struct thread_node *thread = NULL;

  if (0
#if defined _POSIX_CPUTIME && _POSIX_CPUTIME >= 0
      || clock_id == CLOCK_PROCESS_CPUTIME_ID
#endif
#if defined _POSIX_THREAD_CPUTIME && _POSIX_THREAD_CPUTIME >= 0
      || clock_id == CLOCK_THREAD_CPUTIME_ID
#endif
      )
    {
      /* We don't allow timers for CPU clocks.  At least not in the
	 moment.  */
      __set_errno (ENOTSUP);
      return -1;
    }

  if (clock_id != CLOCK_REALTIME)
    {
      __set_errno (EINVAL);
      return -1;
    }

  pthread_once (&__timer_init_once_control, __timer_init_once);

  if (__timer_init_failed)
    {
      __set_errno (ENOMEM);
      return -1;
    }

  pthread_mutex_lock (&__timer_mutex);

  newtimer = __timer_alloc ();
  if (__builtin_expect (newtimer == NULL, 0))
    {
      __set_errno (EAGAIN);
      goto unlock_bail;
    }

  if (evp != NULL)
    newtimer->event = *evp;
  else
    {
      newtimer->event.sigev_notify = SIGEV_SIGNAL;
      newtimer->event.sigev_signo = SIGALRM;
      newtimer->event.sigev_value.sival_ptr = timer_ptr2id (newtimer);
      newtimer->event.sigev_notify_function = 0;
    }

  newtimer->event.sigev_notify_attributes = &newtimer->attr;
  newtimer->creator_pid = getpid ();

  switch (__builtin_expect (newtimer->event.sigev_notify, SIGEV_SIGNAL))
    {
    case SIGEV_NONE:
    case SIGEV_SIGNAL:
      /* We have a global thread for delivering timed signals.
	 If it is not running, try to start it up.  */
      thread = &__timer_signal_thread_rclk;
      if (! thread->exists)
	{
	  if (__builtin_expect (__timer_thread_start (thread),
				1) < 0)
	    {
	      __set_errno (EAGAIN);
	      goto unlock_bail;
            }
        }
      break;

    case SIGEV_THREAD:
      /* Copy over thread attributes or set up default ones.  */
      if (evp->sigev_notify_attributes)
	newtimer->attr = *(pthread_attr_t *) evp->sigev_notify_attributes;
      else
	pthread_attr_init (&newtimer->attr);

      /* Ensure thread attributes call for deatched thread.  */
      pthread_attr_setdetachstate (&newtimer->attr, PTHREAD_CREATE_DETACHED);

      /* Try to find existing thread having the right attributes.  */
      thread = __timer_thread_find_matching (&newtimer->attr, clock_id);

      /* If no existing thread has these attributes, try to allocate one.  */
      if (thread == NULL)
	thread = __timer_thread_alloc (&newtimer->attr, clock_id);

      /* Out of luck; no threads are available.  */
      if (__builtin_expect (thread == NULL, 0))
	{
	  __set_errno (EAGAIN);
	  goto unlock_bail;
	}

      /* If the thread is not running already, try to start it.  */
      if (! thread->exists
	  && __builtin_expect (! __timer_thread_start (thread), 0))
	{
	  __set_errno (EAGAIN);
	  goto unlock_bail;
	}
      break;

    default:
      __set_errno (EINVAL);
      goto unlock_bail;
    }

  newtimer->clock = clock_id;
  newtimer->abstime = 0;
  newtimer->armed = 0;
  newtimer->thread = thread;

  *timerid = timer_ptr2id (newtimer);
  retval = 0;

  if (__builtin_expect (retval, 0) == -1)
    {
    unlock_bail:
      if (thread != NULL)
	__timer_thread_dealloc (thread);
      if (newtimer != NULL)
	{
	  timer_delref (newtimer);
	  __timer_dealloc (newtimer);
	}
    }

  pthread_mutex_unlock (&__timer_mutex);

  return retval;
}
Example #3
0
/* 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;
}