/usr/include/urcu/futex.h is in liburcu-dev 0.9.1-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | #ifndef _URCU_FUTEX_H
#define _URCU_FUTEX_H
/*
* urcu-futex.h
*
* Userspace RCU - sys_futex/compat_futex header.
*
* Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <urcu/config.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
/*
* sys_futex compatibility header.
* Use *only* *either of* futex_noasync OR futex_async on a given address.
*
* futex_noasync cannot be executed in signal handlers, but ensures that
* it will be put in a wait queue even in compatibility mode.
*
* futex_async is signal-handler safe for the wakeup. It uses polling
* on the wait-side in compatibility mode.
*
* BEWARE: sys_futex() FUTEX_WAIT may return early if interrupted
* (returns EINTR).
*/
extern int compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3);
extern int compat_futex_async(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3);
#ifdef CONFIG_RCU_HAVE_FUTEX
#include <unistd.h>
#include <errno.h>
#include <urcu/compiler.h>
#include <urcu/arch.h>
static inline int futex(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
{
return syscall(__NR_futex, uaddr, op, val, timeout,
uaddr2, val3);
}
static inline int futex_noasync(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
{
int ret;
ret = futex(uaddr, op, val, timeout, uaddr2, val3);
if (caa_unlikely(ret < 0 && errno == ENOSYS)) {
return compat_futex_noasync(uaddr, op, val, timeout,
uaddr2, val3);
}
return ret;
}
static inline int futex_async(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
{
int ret;
ret = futex(uaddr, op, val, timeout, uaddr2, val3);
if (caa_unlikely(ret < 0 && errno == ENOSYS)) {
return compat_futex_async(uaddr, op, val, timeout,
uaddr2, val3);
}
return ret;
}
#else
static inline int futex_noasync(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
{
return compat_futex_noasync(uaddr, op, val, timeout, uaddr2, val3);
}
static inline int futex_async(int32_t *uaddr, int op, int32_t val,
const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
{
return compat_futex_async(uaddr, op, val, timeout, uaddr2, val3);
}
#endif
#ifdef __cplusplus
}
#endif
#endif /* _URCU_FUTEX_H */
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