posix/src/prwlockinit.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Allocate resources to use the read-write lock and Initialize it
0009  */
0010
0011 /*
0012  *  POSIX RWLock Manager -- Destroy a RWLock Instance
0013  *
0014  *  COPYRIGHT (c) 1989-2006.
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 RTEMS_STATIC_ASSERT(
0047   offsetof( POSIX_RWLock_Control, flags )
0048     == offsetof( pthread_rwlock_t, _flags ),
0049   POSIX_RWLOCK_CONTROL_FLAGS
0050 );
0051
0052 RTEMS_STATIC_ASSERT(
0053   offsetof( POSIX_RWLock_Control, RWLock.current_state )
0054     == offsetof( pthread_rwlock_t, _current_state ),
0055   POSIX_RWLOCK_CONTROL_CURRENT_STATE
0056 );
0057
0058 RTEMS_STATIC_ASSERT(
0059   offsetof( POSIX_RWLock_Control, RWLock.number_of_readers )
0060     == offsetof( pthread_rwlock_t, _number_of_readers ),
0061   POSIX_RWLOCK_CONTROL_NUMBER_OF_READERS
0062 );
0063
0064 RTEMS_STATIC_ASSERT(
0065   offsetof( POSIX_RWLock_Control, RWLock.Queue )
0066     == offsetof( pthread_rwlock_t, _Queue ),
0067   POSIX_RWLOCK_CONTROL_QUEUE
0068 );
0069
0070 RTEMS_STATIC_ASSERT(
0071   sizeof( POSIX_RWLock_Control ) == sizeof( pthread_rwlock_t ),
0072   POSIX_RWLOCK_CONTROL_SIZE
0073 );
0074
0075 int pthread_rwlock_init(
0076   pthread_rwlock_t           *rwlock,
0077   const pthread_rwlockattr_t *attr
0078 )
0079 {
0080   POSIX_RWLock_Control *the_rwlock;
0081
0082   the_rwlock = _POSIX_RWLock_Get( rwlock );
0083
0084   if ( the_rwlock == NULL ) {
0085     return EINVAL;
0086   }
0087
0088   if ( attr != NULL ) {
0089     if ( !attr->is_initialized ) {
0090       return EINVAL;
0091     }
0092
0093     if ( !_POSIX_Is_valid_pshared( attr->process_shared ) ) {
0094       return EINVAL;
0095     }
0096   }
0097
0098   the_rwlock->flags = (uintptr_t) the_rwlock ^ POSIX_RWLOCK_MAGIC;
0099   _CORE_RWLock_Initialize( &the_rwlock->RWLock );
0100   return 0;
0101 }