pthread_mutex_clocklock Implementation

mutexclocklock.c

/**
 * @file
 *
 * @ingroup POSIXAPI
 *
 * @brief Mutex Clock Lock
 */

/* 
* Copyright (C) 2021 Matthew Joyce
*
* 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.
*/

/* Defining to have access to function prototype in libc/include/pthread.h */
#define _GNU_SOURCE

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

#include <rtems/posix/muteximpl.h>

/**
 * pthread_mutex_clocklock is included in the Issue 8 POSIX Standard
 */
int pthread_mutex_clocklock(
  pthread_mutex_t       *mutex,
  clockid_t             clock_id,
  const struct timespec *abstime
)
{
  /* 
   * This is not specified by the Issue 8 Standard, but including it as an
   * addtional safety check. 
   */ 
  if ( abstime == NULL ) {
    return EINVAL;
  }

  /* 
   * The Issue 8 Standard specifies CLOCK_REALTIME and CLOCK_MONOTONIC as
   * the only supported clocks.
   */
  if ( clock_id == CLOCK_REALTIME ) {
    return _POSIX_Mutex_Lock_support(
      mutex,
      clock_id,
      abstime,
      _Thread_queue_Add_timeout_realtime_timespec
    );
  }
  
  else if ( clock_id == CLOCK_MONOTONIC ) {
    return _POSIX_Mutex_Lock_support(
      mutex,
      clock_id,
      abstime,
      _Thread_queue_Add_timeout_monotonic_timespec
    );
  }
  
  /* 
   * The Issue 8 Standard specifies a return value of EINVAL for unsupported 
   * clocks. 
   */
  else {
    return EINVAL;
  }
}