/* EINA - EFL data type library
 * Copyright (C) 2010 ProFUSION embedded systems
 *
 * 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 2.1 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;
 * if not, see <http://www.gnu.org/licenses/>.
 */

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

#ifdef EFL_HAVE_POSIX_THREADS
# include <pthread.h>
# ifdef __linux__
#  include <sched.h>
#  include <sys/time.h>
#  include <sys/resource.h>
#  include <errno.h>
# endif
#endif

#include "eina_sched.h"
#include "eina_log.h"

#define RTNICENESS 5
#define NICENESS 5

EAPI void
eina_sched_prio_drop(void)
{
#ifdef EFL_HAVE_POSIX_THREADS
   struct sched_param param;
   int pol, prio, ret;
   pthread_t pthread_id;

   pthread_id = pthread_self();
   ret = pthread_getschedparam(pthread_id, &pol, &param);
   if (ret)
     {
        EINA_LOG_ERR("Unable to query sched parameters");
        return;
     }

   if (EINA_UNLIKELY(pol == SCHED_RR || pol == SCHED_FIFO))
     {
        prio = sched_get_priority_max(pol);
        param.sched_priority += RTNICENESS;
        if (prio > 0 && param.sched_priority > prio)
           param.sched_priority = prio;

        pthread_setschedparam(pthread_id, pol, &param);
     }
#ifdef __linux__
   else
     {
        errno = 0;
        prio = getpriority(PRIO_PROCESS, 0);
        if (errno == 0)
          {
             prio += NICENESS;
             if (prio > 19)
                prio = 19;

             setpriority(PRIO_PROCESS, 0, prio);
          }
     }
#endif
#else
   EINA_LOG_ERR("Eina does not have support for threads enabled"
                "or it doesn't support setting scheduler priorities");
#endif
}