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 43 static inline __always_inline int __futex(volatile void* ftx, int op, int value, 44 const struct timespec* timeout, 45 int bitset) { 46 // Our generated syscall assembler sets errno, but our callers (pthread functions) don't want to. 47 int saved_errno = errno; 48 int result = syscall(__NR_futex, ftx, op, value, timeout, NULL, bitset); 49 if (__predict_false(result == -1)) { 50 result = -errno; 51 errno = saved_errno; 52 } 53 return result; 54 } 55 56 static inline int __futex_wake(volatile void* ftx, int count) { 57 return __futex(ftx, FUTEX_WAKE, count, NULL, 0); 58 } 59 60 static inline int __futex_wake_ex(volatile void* ftx, bool shared, int count) { 61 return __futex(ftx, shared ? FUTEX_WAKE : FUTEX_WAKE_PRIVATE, count, NULL, 0); 62 } 63 64 static inline int __futex_wait(volatile void* ftx, int value, const struct timespec* timeout) { 65 return __futex(ftx, FUTEX_WAIT, value, timeout, 0); 66 } 67 68 static inline int __futex_wait_ex(volatile void* ftx, bool shared, int value, 69 bool use_realtime_clock, const struct timespec* abs_timeout) { 70 return __futex(ftx, (shared ? FUTEX_WAIT_BITSET : FUTEX_WAIT_BITSET_PRIVATE) | 71 (use_realtime_clock ? FUTEX_CLOCK_REALTIME : 0), value, abs_timeout, 72 FUTEX_BITSET_MATCH_ANY); 73 } 74 75 __END_DECLS 76 77 #endif /* _BIONIC_FUTEX_H */ 78
