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Diffstat (limited to 'include/semaphore.h')
-rw-r--r-- | include/semaphore.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/include/semaphore.h b/include/semaphore.h new file mode 100644 index 000000000..9c283c864 --- /dev/null +++ b/include/semaphore.h @@ -0,0 +1,88 @@ +/* Linuxthreads - a simple clone()-based implementation of Posix */ +/* threads for Linux. */ +/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ +/* */ +/* This program is free software; you can redistribute it and/or */ +/* modify it under the terms of the GNU Library General Public License */ +/* as published by the Free Software Foundation; either version 2 */ +/* of the License, or (at your option) any later version. */ +/* */ +/* This program is distributed in the hope that it will be useful, */ +/* but WITHOUT ANY WARRANTY; without even the implied warranty of */ +/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */ +/* GNU Library General Public License for more details. */ + +#ifndef _SEMAPHORE_H +#define _SEMAPHORE_H 1 + +#include <features.h> +#include <sys/types.h> +#ifdef __USE_XOPEN2K +# define __need_timespec +# include <time.h> +#endif + +#ifndef _PTHREAD_DESCR_DEFINED +/* Thread descriptors. Needed for `sem_t' definition. */ +typedef struct _pthread_descr_struct *_pthread_descr; +# define _PTHREAD_DESCR_DEFINED +#endif + +/* System specific semaphore definition. */ +typedef struct +{ + struct _pthread_fastlock __sem_lock; + int __sem_value; + _pthread_descr __sem_waiting; +} sem_t; + + + +/* Value returned if `sem_open' failed. */ +#define SEM_FAILED ((sem_t *) 0) + +/* Maximum value the semaphore can have. */ +#define SEM_VALUE_MAX ((int) ((~0u) >> 1)) + + +__BEGIN_DECLS + +/* Initialize semaphore object SEM to VALUE. If PSHARED then share it + with other processes. */ +extern int sem_init (sem_t *__sem, int __pshared, unsigned int __value) __THROW; + +/* Free resources associated with semaphore object SEM. */ +extern int sem_destroy (sem_t *__sem) __THROW; + +/* Open a named semaphore NAME with open flaot OFLAG. */ +extern sem_t *sem_open (__const char *__name, int __oflag, ...) __THROW; + +/* Close descriptor for named semaphore SEM. */ +extern int sem_close (sem_t *__sem) __THROW; + +/* Remove named semaphore NAME. */ +extern int sem_unlink (__const char *__name) __THROW; + +/* Wait for SEM being posted. */ +extern int sem_wait (sem_t *__sem) __THROW; + +#ifdef __USE_XOPEN2K +/* Similar to `sem_wait' but wait only until ABSTIME. */ +extern int sem_timedwait (sem_t *__restrict __sem, + __const struct timespec *__restrict __abstime) + __THROW; +#endif + +/* Test whether SEM is posted. */ +extern int sem_trywait (sem_t *__sem) __THROW; + +/* Post SEM. */ +extern int sem_post (sem_t *__sem) __THROW; + +/* Get current value of SEM and store it in *SVAL. */ +extern int sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval) + __THROW; + +__END_DECLS + +#endif /* semaphore.h */ |