pthread_join（）在IOS上失敗

Question

我正在開發IOS上的多線程項目。 在我的項目中，pthread加入失敗了。

pthread_join(thread_id, NULL) == 0 

注意：這僅僅是發生在IOS，它是隨機的。 失敗連接操作的原因可能是什麼。

Answer 1

手冊頁說：

[EDEADLK]   A deadlock was detected or the value of thread speci- 
        fies the calling thread. 

[EINVAL]   The implementation has detected that the value speci- 
        fied by thread does not refer to a joinable thread. 

[ESRCH]   No thread could be found corresponding to that speci- 
        fied by the given thread ID, thread. 

Answer 2

我有同樣的問題，並發現了一個簡單的解決方案：如果

錯誤 在pthread_join（）將失敗不要調用pthread_detach（）。根據文檔，pthread_detach將腳踏板移動到不能再連接的狀態，所以pthread_join在EINVAL中失敗。

的源代碼可能是這個樣子：

pthread_t  thread; 
pthread_attr_t threadAttr; 

bool run = true; 
void *runFunc(void *p) { 
    while (run) { ... } 
} 

- (void)testThread { 
    int status = pthread_attr_init(&threadAttr); 
    NSLog(@"pthread_attr_init status: %d", status); 
    status = pthread_attr_setdetachstate(&threadAttr, PTHREAD_CREATE_JOINABLE); 
    NSLog(@"pthread_attr_setdetachstate status: %d", status); 
    status = pthread_create(&thread, &threadAttr, &runFunc, (__bridge void *)self); 
    NSLog(@"pthread_create status: %d", status); 
    /* let the thread run ... */ 
    run = false; 
    status = pthread_join(thread, NULL); 
    NSLog(@"pthread_join status: %d == %d, ?", status, EINVAL); 
}