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


typedef struct {

	int a;
	char * msg;

} thread_parameter_t;

typedef struct {

	int b;
	char * buffer;

} thread_result_t;



void * thread_entry_point(void * arg) {

	printf("[thread] ok!\n");

	thread_parameter_t * param = arg;

	printf("[thread] param->a = %d\n", param->a);
	printf("[thread] param->msg = %s\n", param->msg);



	printf("[thread] bye\n");

	return "prova di risultato da thread\n";
	//return NULL;
}

pthread_t t3;

void * thread_entry_point_3(void * arg) {
	printf("[thread3] inizio\n");

	sleep(2);

	printf("[thread3] fine\n");

	return NULL;
}

void * thread_entry_point_2(void * arg) {

	printf("[thread2] ok!\n");

	thread_parameter_t * param = arg;

	printf("[thread2] param->a = %d\n", param->a);
	printf("[thread2] param->msg = %s\n", param->msg);

	printf("[thread2] bye\n");

	// t2 fa questo:
	// crea un thread t3
	// mail join su t3 verrà fatto dal main thread
	// quindi main thread deve avere accesso al thread id di t3

	int res;
	res = pthread_create(&t3,
						 NULL,
						 thread_entry_point_3,
						 NULL
						 );

	if (res != 0) {
		perror("pthread_create");
		exit(1);
	}

	thread_result_t * result = malloc(sizeof(thread_result_t));
	if (result == NULL) {
		perror("malloc");
		exit(1);
	}


	result->b = 4321;
	result->buffer = "ok!";

	pthread_exit(result);
	// equivalente a :
	// return result;

	//return "prova di risultato da thread\n";
	//return NULL;
}



int main() {

	pthread_t t1;
	pthread_t t2;

	int res;

	thread_parameter_t param;

	param.a = 1234;
	param.msg = "ciao!";


	res = pthread_create(&t1,
						 NULL,
						 thread_entry_point,
						 &param
						 );

	if (res != 0) {
		perror("pthread_create");
		exit(1);
	}

	res = pthread_create(&t2,
						 NULL,
						 thread_entry_point_2,
						 &param
						 );
	if (res != 0) {
		perror("pthread_create");
		exit(1);
	}

	printf("[main] thread ID del main thread = %ld\n", pthread_self());
	printf("[main] Thread ID del thread t1 = %ld\n", t1);
	printf("[main] Thread ID del thread t2 = %ld\n", t2);

	//sleep(1);
	void * thread_result;

	printf("[main] prima di pthread_join su t1\n");
	res = pthread_join(t1, &thread_result);
	if (res != 0) {
		perror("pthread_join");
		exit(1);
	}

	thread_result_t * thread_result_2;

	printf("[main] prima di pthread_join su t2\n");
	res = pthread_join(t2, &thread_result_2);
	if (res != 0) {
		perror("pthread_join");
		exit(1);
	}

	printf("[main] prima di pthread_join su t3\n");
	res = pthread_join(t3, NULL);
	if (res != 0) {
		perror("pthread_join");
		exit(1);
	}


	printf("risultato del thread t1: %s\n", (char *) thread_result);

	printf("risultato del thread t2: %d\n", thread_result_2->b);
	printf("risultato del thread t2: %s\n", thread_result_2->buffer);

	printf("[main] bye\n");

	return 0;
}