syf

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <semaphore.h>

pthread_mutex_t prod_mutex, cons_mutex;
pthread_cond_t ready_to_produce =PTHREAD_COND_INITIALIZER;

pthread_cond_t ready_to_consume =PTHREAD_COND_INITIALIZER;
#define MAX 5

int buf[MAX];
int pid;

void* prod(void *p){
   int index = 0;
   int i;
   pthread_mutex_lock(&prod_mutex);
   for (i=0;i<100;i++){
      buf[index] = i;
      if (index == 0 && i >= 5)
      {
      pthread_cond_wait(&ready_to_produce, &prod_mutex);
      }
      index = (index + 1) % MAX;

      pthread_mutex_unlock(&prod_mutex);
      if (index == 0)
      {
      pthread_mutex_lock(&cons_mutex);
      pthread_cond_signal(&ready_to_consume);
      pthread_mutex_unlock(&cons_mutex);
      }

   }
}
void* kons(void *p){
   int index = 0;
   int i;

   for (i=0;i<100;i++){
            if (index == 0 && i >= 5)
      {
      pthread_cond_wait(&ready_to_consume, &cons_mutex);
      }
      printf("Process %d : %d\n", pid,  buf[index]);
      index = (index + 1) % MAX;
      pthread_mutex_unlock(&cons_mutex);
      if ( index == 0)
      {
      pthread_mutex_lock(&prod_mutex);
      pthread_cond_signal(&ready_to_produce);
      pthread_mutex_unlock(&prod_mutex);

      }

   }
}

int main(){

   pthread_mutex_init(&prod_mutex, NULL);
   pthread_mutex_init(&cons_mutex, NULL);


   pthread_t pth1, pth2, pth3, pth4;
   pthread_create(&pth1, NULL, prod, NULL);
   pthread_create(&pth2, NULL, prod, NULL);
   pthread_create(&pth3, NULL, kons, NULL);
   pthread_create(&pth4, NULL, kons, NULL);
   pthread_join(pth1, NULL);
   pthread_join(pth2, NULL);
   pthread_join(pth3, NULL);
   pthread_join(pth4, NULL);


   pthread_mutex_destroy(&prod_mutex);
   pthread_mutex_destroy(&cons_mutex);
   pthread_cond_destroy(&ready_to_consume);
   pthread_cond_destroy(&ready_to_produce);

}