summaryrefslogblamecommitdiffstats
path: root/cpukit/posix/src/semgetvalue.c
blob: eb7afa855e8acefe32499344beab6487ea9cfb09 (plain) (tree)
1
2
3
4
5
6
7
8
9
10

                                           


        
                           

                                      

   
  
                            

                                                    



















                                                                              

   
                    


                   
                                      
 
                 
                          
                         

 











                                                             
           
 
/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup POSIX_SEMAPHORE
 *
 * @brief Get the Value of a Semaphore
 */

/*
 *  COPYRIGHT (c) 1989-2014.
 *  On-Line Applications Research Corporation (OAR).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <rtems/posix/semaphoreimpl.h>

int sem_getvalue(
  sem_t  *__restrict _sem,
  int    *__restrict sval
)
{
  Sem_Control          *sem;
  ISR_Level             level;
  Thread_queue_Context  queue_context;

  POSIX_SEMAPHORE_VALIDATE_OBJECT( _sem );

  sem = _Sem_Get( &_sem->_Semaphore );
  _Thread_queue_Context_initialize( &queue_context );
  _Thread_queue_Context_ISR_disable( &queue_context, level );
  _Sem_Queue_acquire_critical( sem, &queue_context );
  *sval = (int) sem->count;
  _Sem_Queue_release( sem, level, &queue_context );
  return 0;
}