#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include "putNget.h"
#define SUMSIZE 500
static int sum = 0;
static pthread_cond_t  slots_cond = PTHREAD_COND_INITIALIZER;
static pthread_cond_t  items_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t slots_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t items_lock = PTHREAD_MUTEX_INITIALIZER;
static int items = 0;
static int slots = 0;
void *producer(void * arg1){
  int i;
  for (i = 1; i <= SUMSIZE; i++) {
    /* acquire right to a slot */
    pthread_mutex_lock(&slots_lock);
    while (!(slots > 0))
      pthread_cond_wait (&slots_cond, &slots_lock);
    slots--;
    pthread_mutex_unlock(&slots_lock);
    put_item(i*i);
    /* release right to an item */
    pthread_mutex_lock(&items_lock);
    items++;
    pthread_cond_signal(&items_cond);
    pthread_mutex_unlock(&items_lock);
  }
  pthread_exit(NULL);
}
void *consumer(void *arg2){
  int myitem;
  int i;
  for (i = 1; i <= SUMSIZE; i++) {
    pthread_mutex_lock(&items_lock);
    while(!(items > 0))
      pthread_cond_wait(&items_cond, &items_lock);
    items--;
    pthread_mutex_unlock(&items_lock);
    get_item(&myitem);
    sum += myitem;
    pthread_mutex_lock(&slots_lock);
    slots++;
    pthread_cond_signal(&slots_cond);
    pthread_mutex_unlock(&slots_lock);
  }
  pthread_exit(NULL);
}

int main(void){
  pthread_t prodtid, constid;
  int i, total;
  slots = get_buffersize();
  total = 0;
  for (i = 1; i <= SUMSIZE; i++)
    total += i*i;
  printf("The checksum is %d\n", total);
  if (pthread_create(&constid, NULL, consumer, NULL)){
    perror("Could not create consumer");
    exit(EXIT_FAILURE);
  }
  if (pthread_create(&prodtid, NULL, producer, NULL)){
    perror("Could not create producer");
    exit(EXIT_FAILURE);
  }
  pthread_join(prodtid, NULL);
  pthread_join(constid, NULL);
  printf("The threads produced the sum %d\n", sum);
  exit(EXIT_SUCCESS);
}