sysdeps/htl/pt-cond-brdcast.c

   1 /* Broadcast a condition.  Generic version.
   2    Copyright (C) 2000-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library;  if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <pthread.h>
  20
  21 #include <pt-internal.h>
  22
  23 /* Unblock all threads that are blocked on condition variable COND.  */
  24 int
  25 __pthread_cond_broadcast (pthread_cond_t *cond)
  26 {
  27   struct __pthread *wakeup;
  28
  29   __pthread_spin_wait (&cond->__lock);
  30   while ((wakeup = cond->__queue))
  31     {
  32       __pthread_dequeue (wakeup);
  33       __pthread_spin_unlock (&cond->__lock);
  34       /* Wake it up without spin held, so it may have a chance to really
  35          preempt us */
  36       __pthread_wakeup (wakeup);
  37       __pthread_spin_wait (&cond->__lock);
  38     }
  39   __pthread_spin_unlock (&cond->__lock);
  40
  41   return 0;
  42 }
  43
  44 weak_alias (__pthread_cond_broadcast, pthread_cond_broadcast);