/* philosophers.c	dining philosophers using semaphores */
#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 "simphil.h"
#define Philosophers 5

void cleanup( void ) {    /* removes semaphores */
  rm_sem( forks );
  printf( "end of cleanup\n" );
  exit(1);
}

void *phil( void * arg ) { /* function for each philosopher */
  int *me, j;

  me = (int *) arg;

  for( j=0; j<3; j++ ) {
                                          /* acquire the */
    SimOps( forks, *me, (*me+1) % 5, -1 );  /* forks */

    printf( "Philosopher %d Eating !!\n", *me );
    srand( time( NULL ) ); /* eat for between */
    sleep((rand() % 15) + 2);   /* 2 and 16 seconds */
    printf( "Philosopher %d Thinking!!\n", *me );

                                        /* release the forks */
    SimOps( forks, *me, (*me+1) % 5, 1 );

    sleep(rand() % 20); /* think for between 0 and 19 seconds */
  }
  pthread_exit( NULL );
}

int main( void ) {
  int i;
  pthread_t tid[Philosophers];
  int id[Philosophers];
  union semun {
    int val;
    struct semid_ds *buf;
    ushort *array;
  } arg;

  set_the_table();       /* establish the sem set */
  arg.val = 1;
  for( i=0; i<Philosophers; i++ )   /* set each sem to 1 */
    if( semctl( forks, i, SETVAL, arg ) == -1 )
      printf( "semctl\n" );
 
  for( i=0; i<Philosophers; i++ ) /* set up philosopher ids */
    id[i] = i;
  for( i=0; i<Philosophers; i++ )
    pthread_create( &tid[i], NULL, phil, (void *) &id[i] );
  for( i=0; i<Philosophers; i++ )
    pthread_join( tid[i], NULL );
  cleanup();
  return 0;
}