forked from Imagelibrary/rtems
159 lines
2.6 KiB
C
159 lines
2.6 KiB
C
/**
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* @file
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*
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* @brief Private Support Information for POSIX Semaphores
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*
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* This file contains definitions that are internal to the RTEMS
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* implementation of POSIX Semaphores.
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*/
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/*
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* COPYRIGHT (c) 1989-2011.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*/
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#ifndef _SEMAPHORE_H
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#define _SEMAPHORE_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* @defgroup POSIX_SEMAPHORE POSIX Semaphores Support
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*
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* @ingroup POSIXAPI
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*
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* @brief Private Support Information for POSIX Semaphores
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*/
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#include <unistd.h>
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#if defined(_POSIX_SEMAPHORES)
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#include <sys/time.h>
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/*
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* 11.1 Semaphore Characteristics, P1003.1b-1993, p.219
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*/
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typedef int sem_t;
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/*
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* Bad semaphore Id
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*/
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#define SEM_FAILED (sem_t *) -1
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/*
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* 11.2.1 Initialize an Unnamed Semaphore, P1003.1b-1993, p.219
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*/
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int sem_init(
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sem_t *sem,
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int pshared,
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unsigned int value
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);
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/**
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* @brief Destroy an unnamed semaphore.
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*
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* 11.2.2 Destroy an Unnamed Semaphore, P1003.1b-1993, p.220
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*/
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int sem_destroy(
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sem_t *sem
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);
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/*
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* 11.2.3 Initialize/Open a Named Semaphore, P1003.1b-1993, p.221
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*
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* NOTE: Follows open() calling conventions.
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*/
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sem_t *sem_open(
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const char *name,
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int oflag,
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...
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);
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/**
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* @brief Close a named semaphore.
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*
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* Routine to close a semaphore that has been opened or initialized.
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*
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* 11.2.4 Close a Named Semaphore, P1003.1b-1993, p.224
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*/
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int sem_close(
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sem_t *sem
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);
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/**
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* @brief Remove a named semaphore.
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*
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* Unlinks a named semaphore, sem_close must also be called to remove
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* the semaphore.
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*
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* 11.2.5 Remove a Named Semaphore, P1003.1b-1993, p.225
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*/
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int sem_unlink(
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const char *name
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);
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/**
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* @brief Lock a semaphore.
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*
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* 11.2.6 Lock a Semaphore, P1003.1b-1993, p.226
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*
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* NOTE: P1003.4b/D8 adds sem_timedwait(), p. 27
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*/
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int sem_wait(
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sem_t *sem
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);
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/**
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* @brief Lock a semaphore.
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*
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* @see sem_wait()
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*/
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int sem_trywait(
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sem_t *sem
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);
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#if defined(_POSIX_TIMEOUTS)
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/**
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* @brief Lock a semaphore.
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*/
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int sem_timedwait(
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sem_t *__restrict sem,
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const struct timespec *__restrict timeout
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);
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#endif
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/**
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* @brief Unlock a semaphore.
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*
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* 11.2.7 Unlock a Semaphore, P1003.1b-1993, p.227
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*/
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int sem_post(
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sem_t *sem
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);
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/**
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* @brief Get the value of a semaphore.
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*
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* 11.2.8 Get the Value of a Semaphore, P1003.1b-1993, p.229
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*/
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int sem_getvalue(
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sem_t *__restrict sem,
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int *__restrict sval
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);
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#endif /* _POSIX_SEMAPHORES */
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#ifdef __cplusplus
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}
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#endif
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#endif
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/* end of include file */
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