1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #ifndef _BIONIC_FUTEX_H
29 #define _BIONIC_FUTEX_H
30
31 #include <errno.h>
32 #include <linux/futex.h>
33 #include <stdbool.h>
34 #include <stddef.h>
35 #include <sys/cdefs.h>
36 #include <sys/syscall.h>
37 #include <unistd.h>
38
39 __BEGIN_DECLS
40
41 struct timespec;
42
__futex(volatile void * ftx,int op,int value,const struct timespec * timeout)43 static inline __always_inline int __futex(volatile void* ftx, int op, int value, const struct timespec* timeout) {
44 // Our generated syscall assembler sets errno, but our callers (pthread functions) don't want to.
45 int saved_errno = errno;
46 int result = syscall(__NR_futex, ftx, op, value, timeout);
47 if (__predict_false(result == -1)) {
48 result = -errno;
49 errno = saved_errno;
50 }
51 return result;
52 }
53
__futex_wake(volatile void * ftx,int count)54 static inline int __futex_wake(volatile void* ftx, int count) {
55 return __futex(ftx, FUTEX_WAKE, count, NULL);
56 }
57
__futex_wake_ex(volatile void * ftx,bool shared,int count)58 static inline int __futex_wake_ex(volatile void* ftx, bool shared, int count) {
59 return __futex(ftx, shared ? FUTEX_WAKE : FUTEX_WAKE_PRIVATE, count, NULL);
60 }
61
__futex_wait(volatile void * ftx,int value,const struct timespec * timeout)62 static inline int __futex_wait(volatile void* ftx, int value, const struct timespec* timeout) {
63 return __futex(ftx, FUTEX_WAIT, value, timeout);
64 }
65
__futex_wait_ex(volatile void * ftx,bool shared,int value,const struct timespec * timeout)66 static inline int __futex_wait_ex(volatile void* ftx, bool shared, int value, const struct timespec* timeout) {
67 return __futex(ftx, shared ? FUTEX_WAIT : FUTEX_WAIT_PRIVATE, value, timeout);
68 }
69
70 __END_DECLS
71
72 #endif /* _BIONIC_FUTEX_H */
73