linux线程回收

int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
                   void *(*start_routine) (void *), void *arg);

void pthread_exit(void *retval);

1. 设置线程属性
如果线程创建时，attr属性设置为NULL，那么线程采用默认的属性joinable。需要将属性设置为detached

int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate);
int pthread_attr_getdetachstate(pthread_attr_t *attr, int *detachstate);

pthread_t thread_id;
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_create(&thread_id, &attr, func, NULL);
pthread_attr_destroy(&attr);

2. pthread_join
阻塞等待线程退出，并清理（类似于wait, waitpid)

int pthread_join(pthread_t thread, void **retval);

pthread_join(thread, (void**)&thread_ret); //父线程调用
printf("thread_ret = %d.\n", *thread_ret);

3. pthread_detach 非阻塞

int pthread_detach(pthread_t thread);

pthread_detach(pthread_self()); //子线程调用