Philosophers/philo/philo_threads.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   philo_threads.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: narnaud <narnaud@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2021/11/26 07:43:48 by narnaud           #+#    #+#             */
/*   Updated: 2022/05/16 22:28:37 by narnaud          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "philosophers.h"

static int safe_print(char *str, t_room *room, int id)
{
	int	ret;
	if (!room->running)
		return (0);
	pthread_mutex_lock(room->lock);
	printf(str, room_clock(), id);
	ret = room->running;
	pthread_mutex_unlock(room->lock);
	return (ret);
}

int	safe_wait(t_room *room, int start, int duration)
{
	int	ret;

	ret = room->running;
	while  (ret && (room_clock() < (start + duration)))
	{
		pthread_mutex_lock(room->lock);
		ret = room->running;
		pthread_mutex_unlock(room->lock);
		usleep(50);
	}
	return (ret);
}


int	waiter(t_room	*room)
{
	int		 *param;
	int		i;
	int		starvest;
	t_philo	*philo;
	int		ret;

	ret = 1;
	pthread_mutex_lock(room->lock);
	i = 0;
	param = room->param;
	starvest = param[MEALS_AMOUNT];	
	while (ret && i < param[PHILO_AMOUNT])
	{
		philo = room->philos[i];
		pthread_mutex_lock(philo->lock);
		if (philo->eat_time + param[DIE_TIME] < room_clock())
		{
			printf("%d %d died\n", room_clock(), i);
			ret = 0;
		}
		if (philo->eat_amount < starvest)
			starvest = philo->eat_amount;
		pthread_mutex_unlock(philo->lock);
		i++;
	}
	pthread_mutex_unlock(room->lock);
	if (starvest == param[MEALS_AMOUNT])
		ret = 0;
	return (ret);
}

void	*philos_life(void *r)
{
	t_room		*room;
	int			*param;
	t_philo		*philo;
	int			id;
	int			id_p;
	
	room = (t_room *)r;
	param = room->param;
	pthread_mutex_lock(room->lock);
	id = room->i;
	printf("Philo %d: \n", id);
	philo = room->philos[id];
	philo->eat_time = room_clock();
	id_p = (id + 1) % param[PHILO_AMOUNT];
	pthread_mutex_unlock(room->lock);
	while (1)
	{
		pthread_mutex_lock(philo->fork);
		if (!safe_print("%d %d has taken a fork\n", room, id))
		{
		pthread_mutex_unlock(philo->fork);
			break ;
		}
		pthread_mutex_lock(room->philos[id_p]->fork);
		safe_print("%d %d has taken a fork\n", room, id);
		if(!safe_print("%d %d is eating\n", room, id))
		{
		pthread_mutex_unlock(philo->fork);
		pthread_mutex_unlock(room->philos[id_p]->fork);
			break;
		}
		pthread_mutex_lock(philo->lock);
		philo->eat_time = room_clock();
		pthread_mutex_unlock(philo->lock);
		if (!safe_wait(room, room_clock(), param[EAT_DURATION]))
		{
		pthread_mutex_unlock(philo->fork);
		pthread_mutex_unlock(room->philos[id_p]->fork);
			break;
		}
		pthread_mutex_unlock(philo->fork);
		pthread_mutex_unlock(room->philos[id_p]->fork);
		if(!safe_print("%d %d is sleeping\n", room, id))
			break ;
		pthread_mutex_lock(philo->lock);
		philo->eat_amount++;
		pthread_mutex_unlock(philo->lock);
		if (!safe_wait(room, room_clock(), param[SLEEP_DURATION]))
			break ;
		if (!safe_print("%d %d is thinking\n", room, id))
			break ;
	}
	return (NULL);
}

int	room_clock()
{
	struct timeval	time;
	int		ret;
	static long int	start_time = 0;

	gettimeofday(&time, NULL);
	if (!start_time)
		start_time = time.tv_sec * 1000 + time.tv_usec / 1000; 
	ret = (int)(time.tv_sec * 1000 + time.tv_usec / 1000 - start_time);
	return (ret);
}