#include <stdio.h>
#include <signal.h>
#include <pthread.h>

pthread_mutex_t mutex;

void signal_rec(int sig_num)
  {
  printf("The child is done\n");
  pthread_mutex_unlock(&mutex);
  }

int main(int argc, char *argv[])
  {
  int ret_value;

  signal(SIGCHLD, signal_rec);

  mutex=PTHREAD_MUTEX_INITIALIZER;
  ret_value=pthread_mutex_lock(&mutex);
  printf("thread locked %d\n",ret_value);
  ret_value=fork();
  if (ret_value==0)
    {
    printf("I'm the child\n");
    sleep(5);
    printf("ahh, what a good nap\n");
    }
  else
    {
    printf("I'm the parent\n");
//    sleep(10);
    ret_value = pthread_mutex_lock(&mutex);
    printf("heh, I'm done %d\n",ret_value);
    }

  return 0;
  }