posix/src/semtimedwait.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIX_SEMAPHORE POSIX Semaphores Support
0007  *
0008  * @brief Lock a Semaphore
0009  */
0010
0011 /*
0012  *  COPYRIGHT (c) 1989-2008.
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 #include <rtems/score/todimpl.h>
0043
0044 /*
0045  *  11.2.6 Lock a Semaphore, P1003.1b-1993, p.226
0046  *
0047  *  NOTE: P1003.4b/D8 adds sem_timedwait(), p. 27
0048  */
0049
0050 int sem_timedwait(
0051   sem_t                 *__restrict _sem,
0052   const struct timespec *__restrict abstime
0053 )
0054 {
0055   Sem_Control          *sem;
0056   Thread_queue_Context  queue_context;
0057   ISR_Level             level;
0058   Thread_Control       *executing;
0059   unsigned int          count;
0060
0061   POSIX_SEMAPHORE_VALIDATE_OBJECT( _sem );
0062
0063   sem = _Sem_Get( &_sem->_Semaphore );
0064   _Thread_queue_Context_initialize( &queue_context );
0065   _Thread_queue_Context_ISR_disable( &queue_context, level );
0066   executing = _Sem_Queue_acquire_critical( sem, &queue_context );
0067
0068   count = sem->count;
0069   if ( RTEMS_PREDICT_TRUE( count > 0 ) ) {
0070     sem->count = count - 1;
0071     _Sem_Queue_release( sem, level, &queue_context );
0072     return 0;
0073   } else {
0074     Status_Control status;
0075
0076     _Thread_queue_Context_set_thread_state(
0077       &queue_context,
0078       STATES_WAITING_FOR_SEMAPHORE
0079     );
0080     _Thread_queue_Context_set_enqueue_timeout_realtime_timespec(
0081       &queue_context,
0082       abstime,
0083       true
0084     );
0085     _Thread_queue_Context_set_ISR_level( &queue_context, level );
0086     _Thread_queue_Enqueue(
0087       &sem->Queue.Queue,
0088       SEMAPHORE_TQ_OPERATIONS,
0089       executing,
0090       &queue_context
0091     );
0092     status = _Thread_Wait_get_status( executing );
0093     return _POSIX_Zero_or_minus_one_plus_errno( status );
0094   }
0095 }