/*
 * Mutex demo 
 *
 * Copyright (C) 2002 Paolo Gai
 * Copyright (C) 2007 Luca Abeni
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include <unistd.h>
#include <stdio.h>
#define __USE_UNIX98
#include <pthread.h>

static pthread_mutex_t mymutex, mymutex1;
static int th_cnt;

static void *body(void *arg)
{
  int j;
  
  pthread_mutex_lock(&mymutex1);
  fprintf(stderr, "Thread %d: %s\n", th_cnt++, (char *)arg); 
  pthread_mutex_unlock(&mymutex1);

  pthread_mutex_lock(&mymutex);
  for (j=0; j<20; j++) {
    usleep(500000);
    fprintf(stderr, "%s", (char *)arg);
  }
  pthread_mutex_unlock(&mymutex);

  return NULL;
}

int main(int argc, char *argv[])
{
  pthread_t t1, t2, t3;
  int err;
  pthread_attr_t attrs;
  struct sched_param sp;
  int pmin;

  pthread_mutexattr_t mymutexattr;

  pthread_mutexattr_init(&mymutexattr);
  pthread_mutexattr_setprotocol(&mymutexattr, PTHREAD_PRIO_INHERIT);
  pthread_mutex_init(&mymutex, &mymutexattr);
  pthread_mutex_init(&mymutex1, &mymutexattr);
  pthread_mutexattr_destroy(&mymutexattr);

  pthread_attr_init(&attrs);
  pthread_attr_setinheritsched(&attrs, PTHREAD_EXPLICIT_SCHED);
  pthread_attr_setschedpolicy(&attrs, SCHED_FIFO);
  pmin = sched_get_priority_min(SCHED_FIFO);

  sp.sched_priority = pmin + 1;
  err = pthread_attr_setschedparam(&attrs, &sp);
  err = pthread_create(&t1, &attrs, body, ".");
  if (err) {
    fprintf(stderr, "Error creating thread!\n");
    return -1;
  }

  sp.sched_priority = pmin + 2;
  err = pthread_attr_setschedparam(&attrs, &sp);
  err = pthread_create(&t2, &attrs, body, "#");
  if (err) {
    fprintf(stderr, "Error creating thread!\n");
    return -1;
  }

  sp.sched_priority = pmin + 3;
  err = pthread_attr_setschedparam(&attrs, &sp);
  err = pthread_create(&t3, &attrs, body, "o");
  if (err) {
    fprintf(stderr, "Error creating thread!\n");
    return -1;
  }
  pthread_attr_destroy(&attrs);
 
  pthread_join(t1, NULL);
  pthread_join(t2, NULL);
  pthread_join(t3, NULL);

  printf("\n");

  return 0;
}