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. */ |
25 | int |
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 | |
42 | weak_alias (__pthread_cond_signal, pthread_cond_signal); |
43 | |