#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <semaphore.h>

static int x;

void * incrementer(void * tid)
{
  int i = 0;
  for(i = 0; i < 1000; i++)
  {
    x++;
    printf("x from incrementer is %d\n", x);
  }
  pthread_exit(NULL);
}

void * decrementer(void * tid)
{
  int i = 0;
  for(i = 0; i < 1000; i++)
  {
    x--;
    printf("x from decrementer is %d\n", x);
  }
  pthread_exit(NULL);
}

int main(int argc, char ** argv)
{
  pthread_t incr, decr;
  pthread_attr_t attr;

  pthread_attr_init(&attr);

  pthread_attr_setschedpolicy(&attr, SCHED_RR);

  x = 0;

  pthread_create(&incr, &attr, incrementer, (void *) 1);
  pthread_create(&decr, &attr, decrementer, (void *) 2);

  pthread_join(incr, NULL);
  pthread_join(decr, NULL);

  printf("x is %d\n", x);
  return 0;
}