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

sem_t read_s, write_s;
int g_buffer[3] = {0,0,0};
int w_counter = 0;
int r_counter = 0;


//val : 1<=random <= 100
int randomize(){
  return rand()%100 + 1;
}

void * construire_m(void* arg){
  int cpt = 0, val = 0;
  for(cpt = 0; cpt<30; cpt++){

    //generation de la val random
    val = randomize();
    sem_wait(&write_s);
    //write
    g_buffer[w_counter] = val;
    printf("W: [%d] = %d\n", w_counter,g_buffer[w_counter] );
    sem_post(&read_s);
    w_counter = (w_counter +1) % 3;
  }
  pthread_exit(NULL);

}

void * consommer_m(void* arg){
  int cpt = 0;
  for(cpt = 0; cpt<30; cpt++){
    sem_wait(&read_s);
    //read
    printf("R: [%d] = %d\n", r_counter, g_buffer[r_counter]);
    sem_post(&write_s);
    r_counter = (r_counter +1) % 3;
  }
  pthread_exit(NULL);
}


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

  int iCtr = 0;
  pthread_t t_write, t_read;

  printf("[+] Initialisation \n");
  //initialisation des semaphores

    sem_init(&read_s , 0, 0);
    sem_init(&write_s, 0, 3);


  //initialisation du seed de rand
  srand(time(NULL));

  printf("[+] Trace : \n");
  //creation des thread
  if(pthread_create(&t_write, NULL,construire_m, NULL))
  {
    printf("Impossible de créer le thread d'ecriture\n");
    exit(1);
  }
  if(pthread_create(&t_read, NULL,consommer_m, NULL))
  {
    printf("Impossible de créer le thread de lecture\n");
    exit(1);
  }

  printf("[+] Threads created\n");

  pthread_join(t_read,NULL);
  pthread_join(t_write,NULL);



  //creation des thread
  return 0;
}