1/* Signal a condition. Generic version.
2 Copyright (C) 2000-2022 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 at least one of the threads that are blocked on condition
24 variable COND. */
25int
26__pthread_cond_signal (pthread_cond_t *cond)
27{
28 struct __pthread *wakeup;
29
30 __pthread_spin_wait (&cond->__lock);
31 wakeup = cond->__queue;
32 if (wakeup != NULL)
33 __pthread_dequeue (wakeup);
34 __pthread_spin_unlock (&cond->__lock);
35
36 if (wakeup != NULL)
37 __pthread_wakeup (wakeup);
38
39 return 0;
40}
41
42weak_alias (__pthread_cond_signal, pthread_cond_signal);
43

source code of glibc/sysdeps/htl/pt-cond-signal.c