From 9a59f5464174909c9bc509f82ad7ce96bb1c0604 Mon Sep 17 00:00:00 2001
From: Hugo LAMY <hulamy@e2r11p6.clusters.42paris.fr>
Date: Thu, 20 Jan 2022 15:45:49 +0100
Subject: [PATCH] save from school

---
 README.md              | 20 +++++++++++++-------
 headers/philo_struct.h |  2 +-
 srcs/exec.c            | 36 ++++++++++++++++++------------------
 srcs/init.c            |  3 ++-
 4 files changed, 34 insertions(+), 27 deletions(-)

diff --git a/README.md b/README.md
index 6dcef95..609b773 100644
--- a/README.md
+++ b/README.md
@@ -4,34 +4,40 @@ options :
 - t_die -> time_to_die
 - t_eat -> time_to_eat
 - t_slp -> time_to_sleep
-- n_eat-> [number_of_times_each_philosopher_must_eat]
+- n_eat -> [number_of_times_each_philosopher_must_eat]
 ```
 
-thread :
+**thread :**
+
 - parts of a process that performs code simultaneously
 - thread are light-weight-process (LWP) that happens inside a process (observe with command `ps -eLf`)
 - a process can be single-threaded or multi-threaded
 - different process have a different PID and different LWP, different thread in the same process have the same PID and different LWP
 - thread vs process :
-  process :
+
+  *process :*
+
   - process is isolated, it doesn't share memory with any other process
   - process is less efficient in communication, it takes more times to create or terminate or switch
   - process speed is not impacted by speed of other process (untill it reach the limit of cpu)
-  thread :
+
+  *thread :*
+
   - thread are not isolated, they share memory with the other threads
   - thread is more efficient in communication, it takes less times to create or terminate or switch
   - thread can become slow if the process does many concurrent tasks
+
 - ressources :
   - https://www.baeldung.com/linux/process-vs-thread
 
-mutex :
+**mutex :**
+
 - mutual exclusion
 - to prevent a part of the code to be performed simultaneously by threads
 - the section of code wraped by a mutex can be access by only one thread at a time
 - the section starts by unlocking a mutex, and end by locking it
 
-
-external function :
+**external function :**
 
 - `memset`      : fill memory with a constant byte
 - `printf`      : format and print data
diff --git a/headers/philo_struct.h b/headers/philo_struct.h
index 6d9440b..7084cf8 100644
--- a/headers/philo_struct.h
+++ b/headers/philo_struct.h
@@ -16,7 +16,7 @@ typedef struct s_philo
 {
 	t_params		*params;
 	int				philo_nbr;
-	int				fork;
+	t_mtx			m_fork;
 	t_mtx			*m_print;
 	struct s_philo	*prev;
 	struct s_philo	*next;
diff --git a/srcs/exec.c b/srcs/exec.c
index 583844a..9541523 100644
--- a/srcs/exec.c
+++ b/srcs/exec.c
@@ -1,32 +1,32 @@
 #include "philo.h"
 
-int	take_forks(t_philo *philo)
+void	print_message(t_philo *philo, char *msg)
 {
-//	pthread_mutex_lock(&mutex);
-	while (philo->fork == 0 || philo->next->fork == 0)
-		continue ;
-	if (philo->fork == 1 && philo->next->fork == 1)
-	{
-		philo->fork = 0;
-		philo->next->fork = 0;
-		ft_printf("%i has taken a fork\n", philo->philo_nbr);
-		return (1);
-	}
-//	pthread_mutex_unlock(&mutex);
-	return (0);
+	pthread_mutex_lock(philo->m_print);
+	ft_printf("%i %s\n", philo->philo_nbr, msg);
+	pthread_mutex_unlock(philo->m_print);
+}
+
+void	take_forks(t_philo *philo)
+{
+	pthread_mutex_lock(&(philo->m_fork));
+		pthread_mutex_lock(&(philo->next->m_fork));
+
+	print_message(philo, "has taken a fork");
+	usleep(philo->params->t_eat);
+
+		pthread_mutex_unlock(&(philo->next->m_fork));
+	pthread_mutex_unlock(&(philo->m_fork));
 }
 
 void	*philo_exec(void *arg)
 {
 	t_philo	*philo;
-	int		nbr;
 
 	philo = (t_philo*)arg;
-	nbr = philo->philo_nbr;
+	print_message(philo, "is thinking");
+	take_forks(philo);
 
-pthread_mutex_lock(philo->m_print);
-ft_printf("%i is thinking\n", philo->philo_nbr);
-pthread_mutex_unlock(philo->m_print);
 
 // eat
 	// "has taken a fork"
diff --git a/srcs/init.c b/srcs/init.c
index da20d78..c3a0b27 100644
--- a/srcs/init.c
+++ b/srcs/init.c
@@ -9,7 +9,8 @@ t_philo	*lst_add_philo(t_philo *philo, t_params *params, t_mtx *m_print, int i)
 		return (NULL);
 	new->params = params;
 	new->philo_nbr = i + 1;
-	new->fork = 1;
+	if (pthread_mutex_init(&(new->m_fork), NULL) != 0)
+		return (NULL);
 	new->m_print = m_print;
 	if (philo)
 		philo->next = new;