rs thread semaphores

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <semaphore.h>

// Costanti di comodo
#define FALSE 0
#define TRUE 1


pthread_mutex_t count_mutex = PTHREAD_MUTEX_INITIALIZER;
sem_t count_sem;
int count, n;

void init_vars (){
	// La coda è inizialmente vuota
	// Inizializzo i semafori
	count = 0;
	n = 3;
	sem_init (&count_sem, 0, 0);
}

void* thread_function_count (void* arg){
	printf("Prima istruzione th: %s", my_id);
	pthread_mutex_lock (&count_mutex);
	count +=1;
	sem_post(&count_sem);
	pthread_mutex_unlock (&count_mutex);
	while(count != n){
		sem_wait(&count_sem);
	}

	printf("Seconda istruzione th: %s", my_id);
	return NULL;

}


int main(int argc, char* argv[]){

	pthread_t T1_thread_id;
	char* T1_name = "t#1";

	pthread_t T2_thread_id;
	char* T2_name = "t#2";

	pthread_t T3_thread_id;
	char* T3_name = "t#3";

	init_vars();

	// Faccio partire i thread
	pthread_create(&T1_thread_id,NULL,&thread_function_count,(void*)T1_name);
	pthread_create(&T2_thread_id,NULL,&thread_function_count,(void*)T2_name);
	pthread_create(&T3_thread_id,NULL,&thread_function_count,(void*)T3_name);

	pthread_join(T1_thread_id,NULL);
	pthread_join(T2_thread_id,NULL);
	pthread_join(T3_thread_id,NULL);

}