1 | /* pthread_barrier_wait. Generic version. |
---|---|
2 | Copyright (C) 2002-2022 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 | #include <assert.h> |
21 | |
22 | #include <pt-internal.h> |
23 | |
24 | int |
25 | pthread_barrier_wait (pthread_barrier_t *barrier) |
26 | { |
27 | __pthread_spin_wait (&barrier->__lock); |
28 | if (--barrier->__pending == 0) |
29 | { |
30 | barrier->__pending = barrier->__count; |
31 | |
32 | if (barrier->__count == 1) |
33 | __pthread_spin_unlock (&barrier->__lock); |
34 | else |
35 | { |
36 | struct __pthread *wakeup; |
37 | unsigned n = 0; |
38 | |
39 | __pthread_queue_iterate (barrier->__queue, wakeup) |
40 | n++; |
41 | |
42 | { |
43 | struct __pthread *wakeups[n]; |
44 | unsigned i = 0; |
45 | |
46 | __pthread_dequeuing_iterate (barrier->__queue, wakeup) |
47 | wakeups[i++] = wakeup; |
48 | |
49 | barrier->__queue = NULL; |
50 | __pthread_spin_unlock (&barrier->__lock); |
51 | |
52 | for (i = 0; i < n; i++) |
53 | __pthread_wakeup (wakeups[i]); |
54 | } |
55 | } |
56 | |
57 | return PTHREAD_BARRIER_SERIAL_THREAD; |
58 | } |
59 | else |
60 | { |
61 | struct __pthread *self = _pthread_self (); |
62 | |
63 | /* Add ourselves to the list of waiters. */ |
64 | __pthread_enqueue (&barrier->__queue, self); |
65 | __pthread_spin_unlock (&barrier->__lock); |
66 | |
67 | __pthread_block (self); |
68 | return 0; |
69 | } |
70 | } |
71 |