posix/src/semclose.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIX_SEMAPHORE
0007  *
0008  * @brief Close a Named Semaphore
0009  */
0010
0011 /*
0012  *  COPYRIGHT (c) 1989-2014.
0013  *  On-Line Applications Research Corporation (OAR).
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  *
0024  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0025  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0027  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0028  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0029  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0030  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0031  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0032  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0033  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0034  * POSSIBILITY OF SUCH DAMAGE.
0035  */
0036
0037 #ifdef HAVE_CONFIG_H
0038 #include "config.h"
0039 #endif
0040
0041 #include <rtems/posix/semaphoreimpl.h>
0042
0043 int sem_close( sem_t *sem )
0044 {
0045   POSIX_Semaphore_Control *the_semaphore;
0046   uint32_t                 open_count;
0047
0048   POSIX_SEMAPHORE_VALIDATE_OBJECT( sem );
0049
0050   if ( !_POSIX_Semaphore_Is_named( sem ) ) {
0051     rtems_set_errno_and_return_minus_one( EINVAL );
0052   }
0053
0054   the_semaphore = _POSIX_Semaphore_Get( sem );
0055
0056   _Objects_Allocator_lock();
0057
0058   open_count = the_semaphore->open_count;
0059
0060   if ( open_count == 0 ) {
0061     _Objects_Allocator_unlock();
0062     rtems_set_errno_and_return_minus_one( EINVAL );
0063   }
0064
0065   if ( open_count == 1 && _POSIX_Semaphore_Is_busy( sem ) ) {
0066     _Objects_Allocator_unlock();
0067     rtems_set_errno_and_return_minus_one( EBUSY );
0068   }
0069
0070   the_semaphore->open_count = open_count - 1;
0071   _POSIX_Semaphore_Delete( the_semaphore );
0072   _Objects_Allocator_unlock();
0073   return 0;
0074 }