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

void incrementa_vetor();
void decrementa_vetor();

int buffer1[5];
int ent1 = 0;
int sai1 = 0;

int dado = 100;

pthread_mutex_t incrementar = PTHREAD_MUTEX_INITIALIZER;


main(){

        pthread_t t1, t2, t3, t4;


        pthread_create(&t1, NULL, (void *) incrementa_vetor, NULL);
        pthread_create(&t2, NULL, (void *) incrementa_vetor, NULL);
        pthread_create(&t3, NULL, (void *) decrementa_vetor, NULL);
        pthread_create(&t4, NULL, (void *) decrementa_vetor, NULL);

        pthread_join(t1, NULL);
        pthread_join(t2, NULL);
        pthread_join(t3, NULL);
        pthread_join(t4, NULL);

}

void incrementa_vetor(){

        while(1){
                sleep(1);
                pthread_mutex_lock(&incrementar);

                buffer1[ent1] = dado++;
                printf("No incrementa_vetor - buffer1: %d\n", buffer1[ent1]);
                getchar();
                ent1 = (ent1 + 1) % 5;
                
                pthread_mutex_unlock(&incrementar);
        }

}


void decrementa_vetor(){

        int local;

        while(1){

                pthread_mutex_lock(&incrementar);

                local = buffer1[sai1];
                printf("No decrementa_vetor - buffer1: %d\n", buffer1[sai1]);
                getchar();
                sai1 = (sai1 + 1) % 5;
                
                pthread_mutex_unlock(&incrementar);
                sleep(1);
        }
}