#include <rtl.h>#include <time.h>#include <pthread.h>#define NTHREAD 5#define THREAD_STACK_SIZE 20000static pthread_t thread;static char preallocated [NTHREAD][THREAD_STACK_SIZE];static pthread_t threads [NTHREAD];void * start_routine(void *param){	int arg = (int) param;	int newthread = arg - 1;	int ret;	pthread_attr_t attr;	rtl_printf("Thread %d is running\n", arg);	if (!arg) {		return 0;	}	rtl_printf("Thread %d creating thread %d\n", arg, newthread);	pthread_attr_init (&attr);	pthread_attr_setstackaddr (&attr, preallocated [newthread]);	pthread_attr_setstacksize (&attr, THREAD_STACK_SIZE);	ret = pthread_create (&threads [newthread], &attr, start_routine, (void *) (newthread));	if (ret) {		rtl_printf("failed to create thread %d\n", newthread);	}	return 0;}int init_module(void) {	return pthread_create (&thread, NULL, start_routine, (void *) NTHREAD);}void cleanup_module(void) {	int i;	pthread_cancel (thread);	pthread_join (thread, NULL);	for (i = 0; i < NTHREAD; i ++) {		if (threads[i]) {			pthread_cancel (threads[i]);			pthread_join(threads[i], NULL);		}	}}