我是线程新手。在这里,如果我评论 pthread_join(thread1, NULL) 那么在输出中有时我会得到
Thread2
Thread1
Thread1
我无法理解为什么 Thread1 跟踪会出现两次以及 pthread_join 的确切功能是什么。
另外,请参考一些针对初学者的线程概念教程。
void *print_message_function( void *ptr );
main()
{
pthread_t thread1, thread2;
char *message1 = "Thread 1";
char *message2 = "Thread 2";
int iret1, iret2;
iret1 = pthread_create( &thread1, NULL, print_message_function, (void*) message1);
iret2 = pthread_create( &thread2, NULL, print_message_function, (void*) message2);
pthread_join( thread1, NULL);
pthread_join( thread2, NULL);
printf("Thread 1 returns: %d\n",iret1);
printf("Thread 2 returns: %d\n",iret2);
exit(0);
}
void *print_message_function( void *ptr )
{
char *message;
message = (char *) ptr;
printf("%s \n", message);
}