1 /* 2 * Copyright 2015 Intel 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 */ 23 24 #ifndef UTIL_FUTEX_H 25 #define UTIL_FUTEX_H 26 27 #if defined(HAVE_LINUX_FUTEX_H) 28 29 #include <limits.h> 30 #include <stdint.h> 31 #include <unistd.h> 32 #include <linux/futex.h> 33 #include <sys/syscall.h> 34 #include <sys/time.h> 35 36 static inline long sys_futex(void *addr1, int op, int val1, const struct timespec *timeout, void *addr2, int val3) 37 { 38 return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3); 39 } 40 41 static inline int futex_wake(uint32_t *addr, int count) 42 { 43 return sys_futex(addr, FUTEX_WAKE, count, NULL, NULL, 0); 44 } 45 46 static inline int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout) 47 { 48 /* FUTEX_WAIT_BITSET with FUTEX_BITSET_MATCH_ANY is equivalent to 49 * FUTEX_WAIT, except that it treats the timeout as absolute. */ 50 return sys_futex(addr, FUTEX_WAIT_BITSET, value, timeout, NULL, 51 FUTEX_BITSET_MATCH_ANY); 52 } 53 54 #endif 55 56 #endif /* UTIL_FUTEX_H */ 57
