#include <stdio.h>
#include <sys/types.h>
#include "shop.h"

void get_haircut()
{
  printf("Customer %d getting a haircut.\n", getpid());
  sleep(2);
}

main( int argc, char *argv[] ) {
  CDATA *data = NULL;
  int i, shmid, mutex, customers, barbers;
  pid_t pid;

  mutex = sem_open(MUTEXKEY);
  customers = sem_open(CUSTOMERSKEY);
  barbers = sem_open(BARBERSKEY);

  shmid = shmget(SHMKEY, sizeof(CDATA), 0);
  if (shmid < 0) {
    fprintf(stderr, "shmget: %s\n", sys_errlist[errno]);
    exit(1);
  }

  data = (CDATA*)shmat(shmid, (char *)0, 0);

  if (data == (CDATA*)-1) {
    fprintf(stderr, "shmat: %s\n", sys_errlist[errno]);
    exit(1);
  }

  sem_wait(mutex);
  if(data->waiting == NUM_CHAIRS) {
    printf("Customer %d finds all the chairs full. Leaving./n", getpid());
    sem_signal(mutex);
    exit(1);
  }

  data->chairs[data->waiting++] = getpid();
  sem_signal(customers);
  sem_signal(mutex);
  sem_wait(barbers);
  get_haircut();

  sem_close(mutex);
  shmdt((char*)data);
  exit(0);
}