/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   exec.c                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: hulamy <hulamy@student.42.fr>              +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/01/31 10:23:55 by hulamy            #+#    #+#             */
/*   Updated: 2022/01/31 18:07:43 by hulamy           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "philo.h"

static void	action_delay(t_philo *philo, int action_time)
{
	struct timeval	stime;
	int				death_time;

	gettimeofday(&stime, NULL);
	death_time = philo->params->t_die - diff_time(philo, &stime);
	if (death_time > action_time)
		usleep(action_time * 1000);
	else if (death_time > 0)
		usleep(philo->params->t_die * 1000);
}

static int	ret_err_unlock(t_mtx *fork1, t_mtx *fork2)
{
	if (fork2)
		pthread_mutex_unlock(fork2);
	if (fork1)
		pthread_mutex_unlock(fork1);
	return (1);
}

/*
Thread #3: lock order "0x54542E8 before 0x54541F8" violated

Observed (incorrect) order is: acquisition of lock at 0x54541F8
   at 0x4C3603C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
   by 0x4011BC: eat (exec.c:27)
   by 0x401119: philo_exec (exec.c:72)
   by 0x4C38C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
   by 0x4E4B6DA: start_thread (pthread_create.c:463)
   by 0x518471E: clone (clone.S:95)

 followed by a later acquisition of lock at 0x54542E8
   at 0x4C3603C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
   by 0x401226: eat (exec.c:32)
   by 0x401119: philo_exec (exec.c:72)
   by 0x4C38C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
   by 0x4E4B6DA: start_thread (pthread_create.c:463)
   by 0x518471E: clone (clone.S:95)
*/
static int	eat(t_philo *philo, t_mtx *fork1, t_mtx *fork2)
{
	pthread_mutex_lock(fork1);
	if (print_message(philo, WHITE, "has taken a fork"))
		return (ret_err_unlock(fork1, NULL));
	if (fork1 == fork2)
		return (ret_err_unlock(fork1, NULL));
	pthread_mutex_lock(fork2);
	if (print_message(philo, WHITE, "has taken a fork"))
		return (ret_err_unlock(fork1, fork2));
	update_time(philo);
	if (print_message(philo, B_YELLOW, "is eating"))
		return (ret_err_unlock(fork1, fork2));
	action_delay(philo, philo->params->t_eat);
	pthread_mutex_lock(&(philo->m_eat));
	philo->eat_count++;
	pthread_mutex_unlock(&(philo->m_eat));
	pthread_mutex_unlock(fork2);
	pthread_mutex_unlock(fork1);
	return (0);
}

/*
//	offset launch :
	if (philo->p_nbr % 2 == 0)
		usleep(10 * 1000);
//	righty / lefty :
	if (philo->p_nbr % 2 == 0)
	{
		fork1 = &(philo->next->m_fork);
		fork2 = &(philo->m_fork);
	}
*/
void	*philo_exec(void *arg)
{
	t_philo	*philo;
	t_mtx	*fork1;
	t_mtx	*fork2;

	philo = (t_philo *)arg;
	init_time(philo);
	fork1 = &(philo->m_fork);
	fork2 = &(philo->next->m_fork);
	if (philo->p_nbr % 2 == 0)
	{
		fork1 = &(philo->next->m_fork);
		fork2 = &(philo->m_fork);
	}
	while (1)
	{
		if (eat(philo, fork1, fork2) != 0)
			break ;
		if (print_message(philo, B_BLUE, "is sleeping"))
			break ;
		action_delay(philo, philo->params->t_slp);
		if (print_message(philo, B_GREEN, "is thinking"))
			break ;
		usleep(1 * 1000);
	}
	return (NULL);
}