Dining philosophers problem

philosophers.c

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

pthread_mutex_t *forks;
pthread_t * philosophers;
pthread_mutex_t output_lock;
int nb_philosopher = 5;

int take(int philosopher, int fork) {
	pthread_mutex_lock(&output_lock);
	int ret = pthread_mutex_trylock(&forks[fork]);
	if(ret == 0)
		printf("Philosopher %i takes fork %i\n", philosopher, fork);
	else 
		printf("Philosopher %i can not take fork %i\n", philosopher, fork);
	pthread_mutex_unlock(&output_lock);
	pthread_yield();
	return ret;
}

void release(int philosopher, int fork) {
	pthread_mutex_lock(&output_lock);
	pthread_mutex_unlock(&forks[fork]);
	printf("Philosopher %i releases fork %i\n", philosopher, fork);
	pthread_mutex_unlock(&output_lock);
	pthread_yield();
}

void eat(int philosopher) {
	pthread_mutex_lock(&output_lock);
	printf("Philosopher %i eats\n", philosopher);
	pthread_mutex_unlock(&output_lock);
}

void philosopher(int id) {
	for(;;)
	if (take(id, id) == 0) {
		if(take(id, (id + 1)%nb_philosopher) == 0) {
			eat(id);
			release(id, (id + 1) % nb_philosopher);
			release(id, id);
			return;
		}
		release(id, id);
	}
}

int main(int argc, char* argv[]) {
	nb_philosopher = atoi(argv[1]);
	forks = malloc(nb_philosopher * sizeof(pthread_mutex_t));
	philosophers = malloc(nb_philosopher * sizeof(pthread_t));

	for (int i = 0; i < nb_philosopher; i++) {
		pthread_create(&philosophers[i], NULL, &philosopher, i);
	}
	for (int i = 0; i < nb_philosopher; i++) {
		pthread_join(philosophers[i], NULL);
	}
}