/* criticalsections.c */
#include <signal.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>
#include "sem_ops.h"
#define THREADS 5

int sem;
int counter;

void *threadfunc( void * arg ) { /* function for each thread */
  int *me;

  me = (int *) arg;

  P( sem );
  counter++;
  printf( "Thread %d running!! counter = %d\n", *me, counter );
  V( sem );

  pthread_exit( NULL );
}

int main( void ) {
  int i;
  pthread_t tid[THREADS];
  int id[THREADS];

  counter = 0;
  sem = semtran( IPC_PRIVATE );
  V( sem );    /* initialise to 1 */

  for( i=0; i<THREADS; i++ ) /* set up thread ids */
    id[i] = i;
  for( i=0; i<THREADS; i++ ) /* run the threads */
    pthread_create( &tid[i], NULL, threadfunc, (void *) &id[i] );
  for( i=0; i<THREADS; i++ ) /* wait for them to finish */
    pthread_join( tid[i], NULL );
  return 0;
}