/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   deadlock_demo.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: ruiferna <ruiferna@student.42porto.com>    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2025/10/08 18:39:44 by ruiferna          #+#    #+#             */
/*   Updated: 2025/10/08 19:26:47 by ruiferna         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdlib.h>

typedef struct s_info
{
	pthread_mutex_t mutex_a;
	pthread_mutex_t mutex_b;
}	t_info;

void *deadlock_1(void *arg)
{
	t_info *shared;
	shared = (t_info *) arg;
	printf("Thread 1: Locking mutex_a first\n");
	pthread_mutex_lock(&shared->mutex_a);
	printf("Thread 1: Got mutex_a, sleeping before trying mutex_b\n");
	usleep(100000);
	printf("Thread 1: Now trying to lock mutex_b (potential deadlock)\n");
	pthread_mutex_lock(&shared->mutex_b);
	printf("Thread 1: Got both mutexes, releasing them\n");
	pthread_mutex_unlock(&shared->mutex_a);
	pthread_mutex_unlock(&shared->mutex_b);
	return (NULL);
}
void *deadlock_2(void *arg)
{
	t_info *shared;
	shared = (t_info *) arg;
	printf("Thread 2: Locking mutex_b first\n");
	pthread_mutex_lock(&shared->mutex_b);
	printf("Thread 2: Got mutex_b, sleeping before trying mutex_a\n");
	usleep(100000);
	printf("Thread 2: Now trying to lock mutex_a (potential deadlock)\n");
	pthread_mutex_lock(&shared->mutex_a);
	printf("Thread 2: Got both mutexes, releasing them\n");
	pthread_mutex_unlock(&shared->mutex_b);
	pthread_mutex_unlock(&shared->mutex_a);
	return (NULL);
}

void *nolock_1(void *arg)
{
	t_info *shared;
	shared = (t_info *) arg;
	printf("Thread 1: Attempting to lock mutex_a first\n");
	pthread_mutex_lock(&shared->mutex_a);
	printf("Thread 1: Locked mutex_a successfully\n");
	usleep(100000);
	printf("Thread 1: Attempting to lock mutex_b second\n");
	pthread_mutex_lock(&shared->mutex_b);
	printf("Thread 1: Locked mutex_b successfully - both mutexes acquired\n");
	pthread_mutex_unlock(&shared->mutex_b);
	printf("Thread 1: Released mutex_b\n");
	pthread_mutex_unlock(&shared->mutex_a);
	printf("Thread 1: Released mutex_a - task completed\n");
	return (NULL);
}
void *nolock_2(void *arg)
{
	t_info *shared;
	shared = (t_info *) arg;
	printf("Thread 2: Attempting to lock mutex_a first (same order as thread 1)\n");
	pthread_mutex_lock(&shared->mutex_a);
	printf("Thread 2: Locked mutex_a successfully\n");
	usleep(100000);
	printf("Thread 2: Attempting to lock mutex_b second\n");
	pthread_mutex_lock(&shared->mutex_b);
	printf("Thread 2: Locked mutex_b successfully - both mutexes acquired\n");
	pthread_mutex_unlock(&shared->mutex_b);
	printf("Thread 2: Released mutex_b\n");
	pthread_mutex_unlock(&shared->mutex_a);
	printf("Thread 2: Released mutex_a - task completed\n");
	return (NULL);
}

int main(int ac, char **av)
{
	pthread_t thread1;
	pthread_t thread2;
	t_info shared;
	
	if (ac != 2)
		return (0);
	
	pthread_mutex_init(&shared.mutex_a, NULL);
	pthread_mutex_init(&shared.mutex_b, NULL);
	
	int mode = atoi(av[1]);
	if (mode != 0 && mode != 1)
	{
		printf("Insert either a 0 (deadlock) or a 1 (no lock)!\n");
		pthread_mutex_destroy(&shared.mutex_a);
		pthread_mutex_destroy(&shared.mutex_b);
		return (0);
	}
	switch (mode)
	{
		case 0:
			pthread_create(&thread1, NULL, deadlock_1, &shared);
			pthread_create(&thread2, NULL, deadlock_2, &shared);
			break;
		case 1:
			pthread_create(&thread1, NULL, nolock_1, &shared);
			pthread_create(&thread2, NULL, nolock_2, &shared);
			break;
	}
	pthread_join(thread1, NULL);
	pthread_join(thread2, NULL);

	pthread_mutex_destroy(&shared.mutex_a);
	pthread_mutex_destroy(&shared.mutex_b);
	return (0);
}