#include <stdio.h> #include <stdlib.h> #include <pthread.h> void *t1(void *args) {  return (void *) 0; } void *t2(void *args) {  printf("thread 2 param[args] = %d\n", args);  pthread_exit((void *) 3); } void *t3(void *args) {  while(1) {   printf("thread 3 is working\n");   sleep(1);  } } int main(int argc, char *argv[]) {  pthread_t thread;  int err;  void *status;  printf("creating thread 1\n");  err = pthread_create(&thread, NULL, t1, NULL);  if(err) {   printf("Can not created thread 1\n");   exit(-1);  }  pthread_join(thread, &status);  printf("thread 1 exit return code %d\n\n", status);    printf("creating thread 2\n");  err = pthread_create(&thread, NULL, t2, (void *) 9);  if(err) {   printf("Can not created thread 2\n");   exit(-2);  }  pthread_join(thread, &status);  printf("thread 2 exit return code %d\n\n", status);     printf("creating thread 3\n");  err = pthread_create(&thread, NULL, t3, NULL);  if(err) {   printf("Can not created thread 3\n");   exit(-3);  }  sleep(10);  pthread_cancel(thread);  pthread_join(thread, &status);  printf("thread 3 exit return code %d\n", status);  return 1; }