stdlib/longlong.h: Add __udiv_w_sdiv prototype.
[glibc.git] / nptl / pthread_cond_broadcast.c
1 /* Copyright (C) 2003-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
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 <http://www.gnu.org/licenses/>. */
18
19 #include <endian.h>
20 #include <errno.h>
21 #include <sysdep.h>
22 #include <lowlevellock.h>
23 #include <pthread.h>
24 #include <pthreadP.h>
25 #include <stap-probe.h>
26
27 #include <shlib-compat.h>
28 #include <kernel-features.h>
29
30
31 int
32 __pthread_cond_broadcast (cond)
33 pthread_cond_t *cond;
34 {
35 LIBC_PROBE (cond_broadcast, 1, cond);
36
37 int pshared = (cond->__data.__mutex == (void *) ~0l)
38 ? LLL_SHARED : LLL_PRIVATE;
39 /* Make sure we are alone. */
40 lll_lock (cond->__data.__lock, pshared);
41
42 /* Are there any waiters to be woken? */
43 if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
44 {
45 /* Yes. Mark them all as woken. */
46 cond->__data.__wakeup_seq = cond->__data.__total_seq;
47 cond->__data.__woken_seq = cond->__data.__total_seq;
48 cond->__data.__futex = (unsigned int) cond->__data.__total_seq * 2;
49 int futex_val = cond->__data.__futex;
50 /* Signal that a broadcast happened. */
51 ++cond->__data.__broadcast_seq;
52
53 /* We are done. */
54 lll_unlock (cond->__data.__lock, pshared);
55
56 /* Wake everybody. */
57 pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex;
58
59 /* Do not use requeue for pshared condvars. */
60 if (mut == (void *) ~0l
61 || PTHREAD_MUTEX_PSHARED (mut) & PTHREAD_MUTEX_PSHARED_BIT)
62 goto wake_all;
63
64 #if (defined lll_futex_cmp_requeue_pi \
65 && defined __ASSUME_REQUEUE_PI)
66 if (USE_REQUEUE_PI (mut))
67 {
68 if (lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, INT_MAX,
69 &mut->__data.__lock, futex_val,
70 LLL_PRIVATE) == 0)
71 return 0;
72 }
73 else
74 #endif
75 /* lll_futex_requeue returns 0 for success and non-zero
76 for errors. */
77 if (!__builtin_expect (lll_futex_requeue (&cond->__data.__futex, 1,
78 INT_MAX, &mut->__data.__lock,
79 futex_val, LLL_PRIVATE), 0))
80 return 0;
81
82 wake_all:
83 lll_futex_wake (&cond->__data.__futex, INT_MAX, pshared);
84 return 0;
85 }
86
87 /* We are done. */
88 lll_unlock (cond->__data.__lock, pshared);
89
90 return 0;
91 }
92
93 versioned_symbol (libpthread, __pthread_cond_broadcast, pthread_cond_broadcast,
94 GLIBC_2_3_2);