summary refs log tree commit diff
path: root/sysdeps/htl/pt-cond-signal.c
blob: a1c0c2adcf00a3da68deb4b454ee507f8839f129 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
/* Signal a condition.  Generic version.
   Copyright (C) 2000-2018 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If
   not, see <http://www.gnu.org/licenses/>.  */

#include <pthread.h>

#include <pt-internal.h>

/* Unblock at least one of the threads that are blocked on condition
   variable COND.  */
int
__pthread_cond_signal (pthread_cond_t *cond)
{
  struct __pthread *wakeup;

  __pthread_spin_lock (&cond->__lock);
  wakeup = cond->__queue;
  if (wakeup != NULL)
    __pthread_dequeue (wakeup);
  __pthread_spin_unlock (&cond->__lock);

  if (wakeup != NULL)
    __pthread_wakeup (wakeup);

  return 0;
}

strong_alias (__pthread_cond_signal, pthread_cond_signal);