diff --git a/Makefile b/Makefile
index f4c94bb..60a39d5 100644
--- a/Makefile
+++ b/Makefile
@@ -7,6 +7,7 @@ OBJS = $(SRCS:.c=.o)
 
 CC = cc
 CFLAGS = -Wall -Wextra -Werror -pthread
+# CFLAGS = -Wall -Wextra -Werror -pthread -g -fsanitize=thread
 
 all: $(NAME)
 
@@ -24,8 +25,15 @@ $(NAME): $(OBJS)
 # number_of_compiles_required
 # dongle_cooldown
 # scheduler
+
 test: $(NAME)
-	./$(NAME) 10 2000 500 200 300 5 50 1
+	./$(NAME) 2 800 200 100 10 5 0 edf
+
+test-val: $(NAME)
+	valgrind --leak-check=full --show-leak-kinds=all ./$(NAME) 2 800 200 100 10 5 0 edf
+	
+test-hel: $(NAME)
+	valgrind --tool=helgrind ./$(NAME) 2 800 200 100 10 5 0 edf
 
 clean:
 	rm -f $(OBJS)
diff --git a/coders/codexion.h b/coders/codexion.h
index daf802e..8562803 100644
--- a/coders/codexion.h
+++ b/coders/codexion.h
@@ -24,17 +24,37 @@ typedef struct s_args
 	int				time_to_refactor;
 	int				number_of_compiles_required;
 	int				dongle_cooldown;
-	int				scheduler;
+	char			*scheduler;
 }					t_args;
 
-typedef struct s_data
+typedef struct s_dongle
+{
+	pthread_mutex_t	lock;
+	long			last_used;
+}					t_dongle;
+
+typedef struct s_coder
 {
-	struct timeval	start;
 	int				coder_id;
+	pthread_t		thread;
+	t_dongle		*right_dongle;
+	t_dongle		*left_dongle;
+	long			last_compile;
+	int				compiles_done;
+	void			*state;
+}					t_coder;
+
+typedef struct s_state
+{
 	t_args			args;
-	pthread_mutex_t	*left_dongle;
-	pthread_mutex_t	*right_dongle;
-}					t_data;
+	t_coder			*coders;
+	t_dongle		*dongles;
+	long			start;
+	int				is_over;
+	pthread_mutex_t	over_mutex;
+	pthread_mutex_t	print_mutex;
+	pthread_t		monitor;
+}					t_state;
 
 t_args				*parse_arguments(int count, char **args);
 
diff --git a/coders/main.c b/coders/main.c
index 2a0273f..a137f15 100644
--- a/coders/main.c
+++ b/coders/main.c
@@ -17,87 +17,140 @@
 #include <sys/time.h>
 #include <unistd.h>
 
-void	compile_op(t_data *data)
+long	now(void)
 {
-	struct timeval	now;
-	int				diff;
+	struct timeval	current;
 
-	gettimeofday(&now, NULL);
-	diff = (now.tv_sec - data->start.tv_sec) * 1000L + (now.tv_usec
-			- data->start.tv_usec) / 1000;
-	printf("%d %d is compiling\n", diff, data->coder_id);
-	usleep(data->args.time_to_compile * 1000L);
+	gettimeofday(&current, NULL);
+	return (current.tv_sec * 1000L + current.tv_usec / 1000);
 }
 
-void	debug_op(t_data *data)
+void	compile_op(t_coder *coder, t_state *state)
 {
-	struct timeval	now;
-	int				diff;
-
-	gettimeofday(&now, NULL);
-	diff = (now.tv_sec - data->start.tv_sec) * 1000L + (now.tv_usec
-			- data->start.tv_usec) / 1000;
-	printf("%d %d is debugging\n", diff, data->coder_id);
-	usleep(data->args.time_to_debug * 1000L);
+	// acquire right dongle
+	pthread_mutex_lock(&coder->left_dongle->lock);
+	coder->left_dongle->last_used = now();
+	pthread_mutex_lock(&state->print_mutex);
+	printf("%ld %d has taken a dongle\n", now() - state->start,
+		coder->coder_id);
+	pthread_mutex_unlock(&state->print_mutex);
+	// acquire right dongle
+	pthread_mutex_lock(&coder->right_dongle->lock);
+	coder->right_dongle->last_used = now();
+	pthread_mutex_lock(&state->print_mutex);
+	printf("%ld %d has taken a dongle\n", now() - state->start,
+		coder->coder_id);
+	pthread_mutex_unlock(&state->print_mutex);
+	coder->last_compile = now();
+	pthread_mutex_lock(&state->print_mutex);
+	printf("%ld %d is compiling\n", now() - state->start, coder->coder_id);
+	pthread_mutex_unlock(&state->print_mutex);
+	usleep(state->args.time_to_compile * 1000L);
+	pthread_mutex_unlock(&coder->left_dongle->lock);
+	pthread_mutex_unlock(&coder->right_dongle->lock);
+	coder->compiles_done += 1;
 }
 
-void	refactor_op(t_data *data)
+void	debug_op(t_coder *coder, t_state *state)
 {
-	struct timeval	now;
-	int				diff;
+	pthread_mutex_lock(&state->print_mutex);
+	printf("%ld %d is debugging\n", now() - state->start, coder->coder_id);
+	pthread_mutex_unlock(&state->print_mutex);
+	usleep(state->args.time_to_debug * 1000L);
+}
 
-	gettimeofday(&now, NULL);
-	diff = (now.tv_sec - data->start.tv_sec) * 1000L + (now.tv_usec
-			- data->start.tv_usec) / 1000;
-	printf("%d %d is refactoring\n", diff, data->coder_id);
-	usleep(data->args.time_to_refactor * 1000L);
+void	refactor_op(t_coder *coder, t_state *state)
+{
+	pthread_mutex_lock(&state->print_mutex);
+	printf("%ld %d is refactoring\n", now() - state->start, coder->coder_id);
+	pthread_mutex_unlock(&state->print_mutex);
+	usleep(state->args.time_to_refactor * 1000L);
 }
 
 void	*run(void *param)
 {
+	t_coder	*coder;
+	t_state	*state;
 	int		i;
-	t_data	*data;
 
-	data = param;
+	coder = param;
+	state = (t_state *)(coder->state);
 	i = 0;
-	while (i < 5)
+	while (i < state->args.number_of_compiles_required)
 	{
-		compile_op(data);
-		debug_op(data);
-		refactor_op(data);
+		compile_op(coder, state);
+		debug_op(coder, state);
+		refactor_op(coder, state);
 		i++;
 	}
 	return (NULL);
 }
 
+void	*monitor(void *param)
+{
+	(void)param;
+	return (NULL);
+}
+
+int	cleanup(t_args *args, t_coder *coders, t_dongle *dongles)
+{
+	if (args)
+		free(args);
+	if (coders)
+		free(coders);
+	if (dongles)
+		free(dongles);
+	return (0);
+}
+
 int	main(int argc, char **argv)
 {
-	t_args			*args;
-	pthread_t		*coders;
-	pthread_mutex_t	*dongles;
-	int				i;
-	struct timeval	start;
-	t_data			*data;
+	int			i;
+	t_args		*args;
+	t_coder		*coders;
+	t_dongle	*dongles;
+	t_state		state;
 
 	args = parse_arguments(argc - 1, &argv[1]);
-	coders = malloc(sizeof(pthread_t) * args->number_of_coders);
-	dongles = malloc(sizeof(pthread_mutex_t) * args->number_of_coders);
-	data = malloc(sizeof(t_data) * args->number_of_coders);
+	if (!args)
+		return (cleanup(args, NULL, NULL));
+	coders = malloc(sizeof(t_coder) * args->number_of_coders);
+	dongles = malloc(sizeof(t_dongle) * args->number_of_coders);
+	if (!coders || !dongles)
+		return (cleanup(args, coders, dongles));
+	state.start = now();
+	state.args = *args;
+	state.is_over = 0;
+	state.coders = coders;
+	state.dongles = dongles;
+	pthread_mutex_init(&state.print_mutex, NULL);
+	pthread_mutex_init(&state.over_mutex, NULL);
 	i = 0;
-	gettimeofday(&start, NULL);
 	while (i < args->number_of_coders)
 	{
-		data[i].args = *args;
-		data[i].coder_id = i + 1;
-		data[i].start = start;
-		pthread_create(&coders[i], NULL, run, (void *)&data[i]);
-		pthread_mutex_init(&dongles[i], NULL);
+		pthread_mutex_init(&dongles[i].lock, NULL);
+		dongles[i].last_used = state.start - args->dongle_cooldown;
 		i++;
 	}
 	i = 0;
 	while (i < args->number_of_coders)
 	{
-		pthread_join(coders[i], NULL);
+		coders[i].coder_id = i + 1;
+		coders[i].compiles_done = 0;
+		coders[i].last_compile = state.start;
+		coders[i].left_dongle = &dongles[i];
+		coders[i].right_dongle = &dongles[(i + 1) % args->number_of_coders];
+		coders[i].state = &state;
+		pthread_create(&coders[i].thread, NULL, run, &coders[i]);
 		i++;
 	}
+	pthread_create(&state.monitor, NULL, monitor, &state);
+	i = 0;
+	while (i < args->number_of_coders)
+	{
+		pthread_join(coders[i].thread, NULL);
+		i++;
+	}
+	pthread_join(state.monitor, NULL);
+	cleanup(args, coders, dongles);
 }
diff --git a/coders/utils.c b/coders/utils.c
index 4c4743d..291b463 100644
--- a/coders/utils.c
+++ b/coders/utils.c
@@ -12,6 +12,7 @@
 
 #include "codexion.h"
 #include <stddef.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -28,22 +29,27 @@ int	isnumeric(char *str)
 
 t_args	*parse_arguments(int count, char **args)
 {
-	int		args_int[8];
+	int		args_int[7];
 	t_args	*data;
 	int		i;
 
-	if (count != 8)
+	if (count != 8 || !(!strcmp(args[7], "fifo") || (!strcmp(args[7], "edf"))))
 		return (NULL);
 	data = malloc(sizeof(t_args));
 	if (!data)
 		return (NULL);
-	i = -1;
-	while (++i < 8)
+	i = 0;
+	while (i < 7)
 	{
 		if (!isnumeric(args[i]))
 			return (NULL);
 		args_int[i] = atoi(args[i]);
+		i++;
 	}
+	if (!strcmp(args[7], "fifo"))
+		data->scheduler = "fifo";
+	else if (!strcmp(args[7], "edf"))
+		data->scheduler = "edf";
 	data->number_of_coders = args_int[0];
 	data->time_to_burnout = args_int[1];
 	data->time_to_compile = args_int[2];
@@ -51,6 +57,5 @@ t_args	*parse_arguments(int count, char **args)
 	data->time_to_refactor = args_int[4];
 	data->number_of_compiles_required = args_int[5];
 	data->dongle_cooldown = args_int[6];
-	data->scheduler = args_int[7];
 	return (data);
 }