#include <rtl.h>#include <time.h>#include <pthread.h>#define NTASKS 3static pthread_t threads[NTASKS];static pthread_mutex_t mutex /* = PTHREAD_MUTEX_INITIALIZER */;static void * start_routine(void *arg){	int ret;	hrtime_t t;	hrtime_t t2;	int sleep = 500000000;	int nthread = (int) arg;	struct sched_param p;	p . sched_priority = 1;	pthread_setschedparam (pthread_self(), SCHED_FIFO, &p);	rtl_printf("thread %d starts on CPU%d\n", nthread, rtl_getcpuid());	ret = pthread_mutex_trylock(&mutex);	rtl_printf ("thread %d: pthread_mutex_trylock returned %d\n", nthread, ret);	if (ret != 0) {		rtl_printf("thread %d: about to pthread_mutex_lock\n", nthread);		t = gethrtime();		ret = pthread_mutex_lock (&mutex);		t2 = gethrtime();		rtl_printf("thread %d: pthread_mutex_lock returned %d (%d ns elapsed)\n", nthread, ret, (unsigned) (t2 - t));	}	rtl_printf("thread %d is about to sleep for %d ns\n", nthread, sleep);	nanosleep (hrt2ts(sleep), NULL);	ret = pthread_mutex_unlock (&mutex);	rtl_printf("thread %d: pthread_mutex_unlock returned %d\n", nthread, ret);	return (void *) 35 + nthread;}int init_module(void){	int ret;	int i;	pthread_attr_t attr;	pthread_mutex_init (&mutex, 0);	rtl_printf("RTLinux mutex test starts on CPU%d\n", rtl_getcpuid());	pthread_attr_init (&attr);	for (i = 0; i < NTASKS; i++) {		/* try to run one thread on another CPU */		if (i == 1 && rtl_cpu_exists(!rtl_getcpuid())) {			pthread_attr_setcpu_np(&attr, !rtl_getcpuid());		}		ret = pthread_create (&threads[i], &attr, start_routine, (void *) i);		if (ret) {			rtl_printf("failed to create a thread\n");			return ret;		}	}	return 0;}void cleanup_module(void){	void *retval;	int i;	for (i = 0; i < 3; i++) {		pthread_join (threads[i], &retval);		rtl_printf("pthread_join on thread %d returned %d\n", i, (int) retval);	}	pthread_mutex_destroy (&mutex);}