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 29 #ifndef _SEMAPHORE_H 30 #define _SEMAPHORE_H 31 32 #include <sys/cdefs.h> 33 34 __BEGIN_DECLS 35 36 struct timespec; 37 38 typedef struct { 39 unsigned int count; 40 #ifdef __LP64__ 41 int __reserved[3]; 42 #endif 43 } sem_t; 44 45 #define SEM_FAILED __BIONIC_CAST(reinterpret_cast, sem_t*, 0) 46 47 int sem_destroy(sem_t* __sem); 48 int sem_getvalue(sem_t* __sem, int* __value); 49 int sem_init(sem_t* __sem, int __shared, unsigned int __value); 50 int sem_post(sem_t* __sem); 51 int sem_timedwait(sem_t* __sem, const struct timespec* __ts); 52 /* 53 * POSIX only supports using sem_timedwait() with CLOCK_REALTIME, however that is typically 54 * inappropriate, since that clock can change dramatically, causing the timeout to either 55 * expire earlier or much later than intended. This function is added to use a timespec based 56 * on CLOCK_MONOTONIC that does not suffer from this issue. 57 */ 58 int sem_timedwait_monotonic_np(sem_t* __sem, const struct timespec* __ts) __INTRODUCED_IN(28); 59 int sem_trywait(sem_t* __sem); 60 int sem_wait(sem_t* __sem); 61 62 /* These aren't actually implemented. */ 63 sem_t* sem_open(const char* __name, int _flags, ...); 64 int sem_close(sem_t* __sem); 65 int sem_unlink(const char* __name); 66 67 __END_DECLS 68 69 #endif 70
