#include	"unpthread.h"void *myfunc(void *ptr){	int		val;	printf("thread ID of myfunc: %d\n", pthread_self());	val = *((int *) ptr);	printf("val = %d\n", val);	sleep(10);	val = *((int *) ptr);	printf("val = %d\n", val);}intmain(int argc, char **argv){	pthread_t	tid;	int			n, val;	printf("thread ID of main: %d\n", pthread_self());	/* Let's verify that the value pointed to the thread's argument is	   modifiable */	val = 123;	if ( (n = pthread_create(&tid, NULL, myfunc, &val)) != 0)		errno = n, err_sys("pthread_create error");	sleep(5);	val = 789;	sleep(20);	exit(0);}