relibc_pthreads-emb/pthread_setschedparam.c

/*
 * sched_setschedparam.c
 *
 * Description:
 * POSIX thread functions that deal with thread scheduling.
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
 *      Copyright(C) 2008 Jason Schmidlapp
 *
 *      Contact Email: jschmidlapp@users.sourceforge.net
 *
 *
 *      Based upon Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 *
 *      Contact Email: rpj@callisto.canberra.edu.au
 *
 *      The original list of contributors to the Pthreads-win32 project
 *      is contained in the file CONTRIBUTORS.ptw32 included with the
 *      source code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation; either
 *      version 2 of the License, or (at your option) any later version.
 *
 *      This library is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *      Lesser General Public License for more details.
 *
 *      You should have received a copy of the GNU Lesser General Public
 *      License along with this library in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include "pthread.h"
#include "implement.h"
#include "sched.h"

int
pthread_setschedparam (pthread_t thread, int policy,
                       const struct sched_param *param)
{
  int result;

  /* Validate the thread id. */
  result = pthread_kill (thread, 0);
  if (0 != result)
    {
      return result;
    }

  /* Validate the scheduling policy. */
  if (policy < SCHED_MIN || policy > SCHED_MAX)
    {
      return EINVAL;
    }

  /* Ensure the policy is SCHED_OTHER. */
  if (policy != SCHED_OTHER)
    {
      return ENOTSUP;
    }

  return (pte_setthreadpriority (thread, policy, param->sched_priority));
}


int
pte_setthreadpriority (pthread_t thread, int policy, int priority)
{
  int prio;
  int result;
  pte_thread_t * tp = (pte_thread_t *) thread;

  prio = priority;

  /* Validate priority level. */
  if (prio < sched_get_priority_min (policy) ||
      prio > sched_get_priority_max (policy))
    {
      return EINVAL;
    }

  result = pthread_mutex_lock (&tp->threadLock);

  if (0 == result)
    {
      /* If this fails, the current priority is unchanged. */

      if (0 != pte_osThreadSetPriority(tp->threadId, prio))
        {
          result = EINVAL;
        }
      else
        {
          /*
           * Must record the thread's sched_priority as given,
           * not as finally adjusted.
           */
          tp->sched_priority = priority;
        }

      (void) pthread_mutex_unlock (&tp->threadLock);
    }

  return result;
}