brb

#include <stdio.h>
#include <stdlib.h>
#include <omp.h>
#include <unistd.h>
#include <time.h>

#define CHAIRS 3
int waiting_customers = 0;
omp_lock_t barber_lock, customer_lock;

void sleeping_barber_sequential() {
    for (int i = 0; i < 10; i++) {
        printf("Customer %d is waiting.\n", i);
        sleep(1);

        printf("Barber is cutting hair.\n");
        sleep(2);
    }
}

void sleeping_barber_parallel() {
    #pragma omp parallel sections
    {
        #pragma omp section
        {
            while (1) {
                omp_set_lock(&barber_lock);
                if (waiting_customers > 0) {
                    waiting_customers--;
                    printf("Barber is cutting hair.\n");
                    sleep(2);
                } else {
                    printf("Barber is sleeping.\n");
                }
                omp_unset_lock(&barber_lock);
                sleep(1);
            }
        }

        #pragma omp section
        {
            for (int i = 0; i < 10; i++) {
                omp_set_lock(&customer_lock);
                if (waiting_customers < CHAIRS) {
                    waiting_customers++;
                    printf("Customer %d is waiting.\n", i);
                } else {
                    printf("Customer %d left because of no chair.\n", i);
                }
                omp_unset_lock(&customer_lock);
                sleep(1);
            }
        }
    }
}

int main() {
    for (int i = 0; i < N; i++) omp_init_lock(&forks[i]);
    omp_init_lock(&barber_lock);

    clock_t start, end;
    printf("\nsleeping barber problem:\n");
    start = clock();
    sleeping_barber_sequential();
    end = clock();
    printf("Sequential Time: %lf seconds\n", (double)(end - start) / CLOCKS_PER_SEC);
}