1 /* Copyright (C) 2002, 2003 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library; if not, see 16 <http://www.gnu.org/licenses/>. */ 17 18 #ifndef _SEMAPHORE_H 19 #define _SEMAPHORE_H 1 20 21 #include <features.h> 22 #include <sys/types.h> 23 #ifdef __USE_XOPEN2K 24 # define __need_timespec 25 # include <time.h> 26 #endif 27 28 /* Get the definition for sem_t. */ 29 #include <bits/semaphore.h> 30 31 32 __BEGIN_DECLS 33 34 /* Initialize semaphore object SEM to VALUE. If PSHARED then share it 35 with other processes. */ 36 extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value) 37 __THROW; 38 /* Free resources associated with semaphore object SEM. */ 39 extern int sem_destroy (sem_t *__sem) __THROW; 40 41 /* Open a named semaphore NAME with open flags OFLAG. */ 42 extern sem_t *sem_open (const char *__name, int __oflag, ...) __THROW; 43 44 /* Close descriptor for named semaphore SEM. */ 45 extern int sem_close (sem_t *__sem) __THROW; 46 47 /* Remove named semaphore NAME. */ 48 extern int sem_unlink (const char *__name) __THROW; 49 50 /* Wait for SEM being posted. 51 52 This function is a cancellation point and therefore not marked with 53 __THROW. */ 54 extern int sem_wait (sem_t *__sem); 55 56 #ifdef __USE_XOPEN2K 57 /* Similar to `sem_wait' but wait only until ABSTIME. 58 59 This function is a cancellation point and therefore not marked with 60 __THROW. */ 61 extern int sem_timedwait (sem_t *__restrict __sem, 62 const struct timespec *__restrict __abstime); 63 #endif 64 65 /* Test whether SEM is posted. */ 66 extern int sem_trywait (sem_t *__sem) __THROWNL; 67 68 /* Post SEM. */ 69 extern int sem_post (sem_t *__sem) __THROWNL; 70 71 /* Get current value of SEM and store it in *SVAL. */ 72 extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval) 73 __THROW; 74 75 76 __END_DECLS 77 78 #endif /* semaphore.h */ 79