1 /* Copyright (C) 2002-2022 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 <https://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 # include <bits/types/struct_timespec.h> 25 #endif 26 27 /* Get the definition for sem_t. */ 28 #include <bits/semaphore.h> 29 30 31 __BEGIN_DECLS 32 33 /* Initialize semaphore object SEM to VALUE. If PSHARED then share it 34 with other processes. */ 35 extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value) 36 __THROW __nonnull ((1)); 37 38 /* Free resources associated with semaphore object SEM. */ 39 extern int sem_destroy (sem_t *__sem) __THROW __nonnull ((1)); 40 41 /* Open a named semaphore NAME with open flags OFLAG. */ 42 extern sem_t *sem_open (const char *__name, int __oflag, ...) 43 __THROW __nonnull ((1)); 44 45 /* Close descriptor for named semaphore SEM. */ 46 extern int sem_close (sem_t *__sem) __THROW __nonnull ((1)); 47 48 /* Remove named semaphore NAME. */ 49 extern int sem_unlink (const char *__name) __THROW __nonnull ((1)); 50 51 /* Wait for SEM being posted. 52 53 This function is a cancellation point and therefore not marked with 54 __THROW. */ 55 extern int sem_wait (sem_t *__sem) __nonnull ((1)); 56 57 #ifdef __USE_XOPEN2K 58 /* Similar to `sem_wait' but wait only until ABSTIME. 59 60 This function is a cancellation point and therefore not marked with 61 __THROW. */ 62 # ifndef __USE_TIME_BITS64 63 extern int sem_timedwait (sem_t *__restrict __sem, 64 const struct timespec *__restrict __abstime) 65 __nonnull ((1, 2)); 66 # else 67 # ifdef __REDIRECT 68 extern int __REDIRECT (sem_timedwait, 69 (sem_t *__restrict __sem, 70 const struct timespec *__restrict __abstime), 71 __sem_timedwait64) 72 __nonnull ((1, 2)); 73 # else 74 # define sem_timedwait __sem_timedwait64 75 # endif 76 # endif 77 #endif 78 79 #ifdef __USE_GNU 80 # ifndef __USE_TIME_BITS64 81 extern int sem_clockwait (sem_t *__restrict __sem, 82 clockid_t clock, 83 const struct timespec *__restrict __abstime) 84 __nonnull ((1, 3)); 85 # else 86 # ifdef __REDIRECT 87 extern int __REDIRECT (sem_clockwait, 88 (sem_t *__restrict __sem, 89 clockid_t clock, 90 const struct timespec *__restrict __abstime), 91 __sem_clockwait64) 92 __nonnull ((1, 3)); 93 # else 94 # define sem_clockwait __sem_clockwait64 95 # endif 96 # endif 97 #endif 98 99 /* Test whether SEM is posted. */ 100 extern int sem_trywait (sem_t *__sem) __THROWNL __nonnull ((1)); 101 102 /* Post SEM. */ 103 extern int sem_post (sem_t *__sem) __THROWNL __nonnull ((1)); 104 105 /* Get current value of SEM and store it in *SVAL. */ 106 extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval) 107 __THROW __nonnull ((1, 2)); 108 109 110 __END_DECLS 111 112 #endif /* semaphore.h */ 113