posix/src/prwlockunlock.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Function Releases a lock held on RWLock object referenced by rwlock
0009  */
0010
0011 /*
0012  *  POSIX RWLock Manager -- Release a lock held on a RWLock Instance
0013  *
0014  *  COPYRIGHT (c) 1989-2007.
0015  *  On-Line Applications Research Corporation (OAR).
0016  *
0017  * Redistribution and use in source and binary forms, with or without
0018  * modification, are permitted provided that the following conditions
0019  * are met:
0020  * 1. Redistributions of source code must retain the above copyright
0021  *    notice, this list of conditions and the following disclaimer.
0022  * 2. Redistributions in binary form must reproduce the above copyright
0023  *    notice, this list of conditions and the following disclaimer in the
0024  *    documentation and/or other materials provided with the distribution.
0025  *
0026  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0027  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0028  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0029  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0030  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0031  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0032  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0033  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0034  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0035  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0036  * POSSIBILITY OF SUCH DAMAGE.
0037  */
0038
0039 #ifdef HAVE_CONFIG_H
0040 #include "config.h"
0041 #endif
0042
0043 #include <rtems/posix/rwlockimpl.h>
0044 #include <rtems/posix/posixapi.h>
0045
0046 #include <string.h>
0047
0048 bool _POSIX_RWLock_Auto_initialization( POSIX_RWLock_Control *the_rwlock )
0049 {
0050   POSIX_RWLock_Control zero;
0051
0052   memset( &zero, 0, sizeof( zero ) );
0053
0054   if ( memcmp( the_rwlock, &zero, sizeof( *the_rwlock ) ) != 0 ) {
0055     return false;
0056   }
0057
0058   the_rwlock->flags = (uintptr_t) the_rwlock ^ POSIX_RWLOCK_MAGIC;
0059   return true;
0060 }
0061
0062 int pthread_rwlock_unlock(
0063   pthread_rwlock_t  *rwlock
0064 )
0065 {
0066   POSIX_RWLock_Control *the_rwlock;
0067   Status_Control        status;
0068
0069   the_rwlock = _POSIX_RWLock_Get( rwlock );
0070   POSIX_RWLOCK_VALIDATE_OBJECT( the_rwlock );
0071
0072   status = _CORE_RWLock_Surrender( &the_rwlock->RWLock );
0073   return _POSIX_Get_error( status );
0074 }