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b168057a | 1 | /* Copyright (C) 2002-2015 Free Software Foundation, Inc. |
76a50749 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. | |
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 | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
76a50749 | 18 | |
73f7c32c | 19 | #include <errno.h> |
bf293afe | 20 | #include <shlib-compat.h> |
76a50749 | 21 | #include "pthreadP.h" |
5acf7263 | 22 | #include <stap-probe.h> |
76a50749 UD |
23 | |
24 | ||
25 | int | |
83614008 | 26 | __pthread_cond_destroy (cond) |
76a50749 UD |
27 | pthread_cond_t *cond; |
28 | { | |
5bd8a249 UD |
29 | int pshared = (cond->__data.__mutex == (void *) ~0l) |
30 | ? LLL_SHARED : LLL_PRIVATE; | |
31 | ||
5acf7263 RM |
32 | LIBC_PROBE (cond_destroy, 1, cond); |
33 | ||
73f7c32c | 34 | /* Make sure we are alone. */ |
5bd8a249 | 35 | lll_lock (cond->__data.__lock, pshared); |
73f7c32c UD |
36 | |
37 | if (cond->__data.__total_seq > cond->__data.__wakeup_seq) | |
38 | { | |
39 | /* If there are still some waiters which have not been | |
40 | woken up, this is an application bug. */ | |
5bd8a249 | 41 | lll_unlock (cond->__data.__lock, pshared); |
73f7c32c UD |
42 | return EBUSY; |
43 | } | |
44 | ||
45 | /* Tell pthread_cond_*wait that this condvar is being destroyed. */ | |
46 | cond->__data.__total_seq = -1ULL; | |
47 | ||
48 | /* If there are waiters which have been already signalled or | |
49 | broadcasted, but still are using the pthread_cond_t structure, | |
50 | pthread_cond_destroy needs to wait for them. */ | |
51 | unsigned int nwaiters = cond->__data.__nwaiters; | |
560b4709 | 52 | |
ee5d5755 | 53 | if (nwaiters >= (1 << COND_NWAITERS_SHIFT)) |
73f7c32c | 54 | { |
560b4709 | 55 | /* Wake everybody on the associated mutex in case there are |
5acf7263 RM |
56 | threads that have been requeued to it. |
57 | Without this, pthread_cond_destroy could block potentially | |
58 | for a long time or forever, as it would depend on other | |
59 | thread's using the mutex. | |
60 | When all threads waiting on the mutex are woken up, pthread_cond_wait | |
61 | only waits for threads to acquire and release the internal | |
62 | condvar lock. */ | |
560b4709 UD |
63 | if (cond->__data.__mutex != NULL |
64 | && cond->__data.__mutex != (void *) ~0l) | |
65 | { | |
66 | pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex; | |
835abc5c | 67 | lll_futex_wake (&mut->__data.__lock, INT_MAX, |
5bd8a249 | 68 | PTHREAD_MUTEX_PSHARED (mut)); |
560b4709 UD |
69 | } |
70 | ||
71 | do | |
72 | { | |
5bd8a249 | 73 | lll_unlock (cond->__data.__lock, pshared); |
73f7c32c | 74 | |
5bd8a249 | 75 | lll_futex_wait (&cond->__data.__nwaiters, nwaiters, pshared); |
73f7c32c | 76 | |
5bd8a249 | 77 | lll_lock (cond->__data.__lock, pshared); |
73f7c32c | 78 | |
560b4709 UD |
79 | nwaiters = cond->__data.__nwaiters; |
80 | } | |
ee5d5755 | 81 | while (nwaiters >= (1 << COND_NWAITERS_SHIFT)); |
73f7c32c UD |
82 | } |
83 | ||
76a50749 UD |
84 | return 0; |
85 | } | |
bf293afe UD |
86 | versioned_symbol (libpthread, __pthread_cond_destroy, |
87 | pthread_cond_destroy, GLIBC_2_3_2); |