gtk编程遇到一个让我不知所措的错误

icoming

不过就算是让新创建的线程先运行然后再调用pthread_cancel，还是会有问题。以下是对上面的这段程序的修改

1. 
   
2. #include <iostream>
   
3. using namespace std;
   
4. #include <pthread.h>
   
5. 
   
6. pthread_cond_t cond=PTHREAD_COND_INITIALIZER;
   
7. pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER;
   
8. bool flag=true;
   
9. 
   
10. void *thread_run(void *)
    
11. {
    
12.     int state;
    
13.     pthread_mutex_lock(&mutex);
    
14.     pthread_cond_signal(&cond);
    
15.     cout<<"------------send a signal"<<endl;
    
16.     pthread_mutex_unlock(&mutex);
    
17.     cout<<"------------thread start"<<endl;
    
18.     while(true){
    
19.         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE , &state);
    
20.         cout<<"-----------thread loop"<<endl;
    
21.         for(int i=0 ; i < 10000 ; i++);
    
22.         cout<<"----------start to sleep"<<endl;
    
23.         pthread_setcancelstate(state , &state);//enable to cancel the thread
    
24.         sleep(1);
    
25.     }
    
26. }
    
27. 
    
28. int main()
    
29. {
    
30.     for(int i=0 ; i < 1000 ; i++){
    
31.         pthread_t id;
    
32.         cout<<"create a thread:"<<i<<endl;
    
33.         pthread_mutex_lock(&mutex);
    
34.         pthread_create(&id , NULL , thread_run , NULL);
    
35.         cout<<"start to wait"<<endl;
    
36.         pthread_cond_wait(&cond , &mutex);
    
37.         pthread_mutex_unlock(&mutex);
    
38.         //cout<<"wait for the new thread to run"<<end;
    
39.         //pthread_cond_wait(&cond , &mutex);
    
40.         cout<<"cancel a thread"<<endl;
    
41.         pthread_cancel(id);
    
42.         void *reval;
    
43.         cout<<"wait for a thread to die"<<endl;
    
44.         pthread_join(id , &reval);
    
45.         cout<<endl<<endl;
    
46.     }
    
47. }
    

复制代码

这段程序照样不能正常的cancel掉新创建的线程

icoming

但是，如果把thread_run函数改成如下，就不会有问题了。
我发现好像只有在调用像sleep()这样的函数(会让线程挂起的函数)的时候被cancel掉，才能整个程序才能正常运行。我不明白为什么会这样。
请大牛指教

1. 
   
2. void *thread_run(void *)
   
3. {
   
4.     int state;
   
5.     pthread_setcancelstate(PTHREAD_CANCEL_DISABLE , &state);
   
6.     pthread_mutex_lock(&mutex);
   
7.     pthread_cond_signal(&cond);
   
8.     cout<<"------------send a signal"<<endl;
   
9.     pthread_mutex_unlock(&mutex);
   
10.     cout<<"------------thread start"<<endl;
    
11.     while(true){
    
12.         cout<<"-----------thread loop"<<endl;
    
13.         for(int i=0 ; i < 10000 ; i++);
    
14.         cout<<"----------start to sleep"<<endl;
    
15.         pthread_setcancelstate(state , &state);//enable to cancel the thread
    
16.         sleep(1);
    
17.         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE , &state);//disable to cancel the thread
    
18.     }
    
19. }
    

复制代码