22 - 3 - 4

线程、静态、信号量

  1. #include<iostream>
  2. #include<thread>
  3. #include<vector>
  4. using namespace std;
  6. // #define sigint_flag true
  7. static int sigint_flag = true;
  9. void thread_say()
  10. {
  11.     cout << "thread id: " << thread::get_id << endl;
  12. };
  14. void thread_pause(int i)
  15. {
  16.     while(sigint_flag){
  17.         // this_thread::sleep_for(chrono::seconds(i));
  18.         this_thread::sleep_for(chrono::seconds(i));
  19.         cout << "threads "<< i <<" id: " << this_thread::get_id()
  20.             << " thread pasue: "<< i 
  21.             << " seconds." << endl;
  22.     }
  23.     cout << "threads " << i << " end\n";
  24. };
  26. void signal_handler(int signum)
  27. {
  28.     cout << "Interrupt signal:" << signum << " received.\n";
  30.     //动态的。编译后可以更改
  31.     sigint_flag = false;
  33.    // 静态的（在编译前编译好了，此时更改无效）
  34.     // #ifdef sigint_flag
  35.     //     #undef sigint_flag
  36.     // #endif
  37.     // #define sigint_flag false
  38. }
  40. int main()
  41. {   
  42.     signal(SIGINT,signal_handler);
  44.     cout <<  "main线程的id: " << this_thread::get_id() << "\n";
  45.     thread t(thread_say);
  46.     cout << t.hardware_concurrency() << endl;//可以并发执行多少个(不准确)
  47.     cout << "native_handle " << t.native_handle() << endl;//可以并发执行多少个(不准确)
  48.     cout <<  "线程t的id: " << t.get_id() << endl;
  49.     //等待线程完成
  50.     //该函数会阻塞当前线程。阻塞调用者(caller)所在的线程直至被join的std::thread对象标识的线程执行结束。
  51.     t.join();
  52.     // thread threads[5];
  53.     vector<thread> threads;                      //线程组
  54.     for (int i = 0; i < 5; i++)
  55.     {
  56.         //threads[i] = thread(thread_pause, i+1);//线程函数，参数
  57.         threads.push_back(thread(thread_pause,i+1));
  58.     }
  60.     cout << "thread jion wait\n" << endl;
  61.     //线程组等待
  62.     for (auto &thread : threads){
  63.          cout << "thread: " <<thread.get_id() << " jion\n";
  64.          thread.join();
  65.      };
  67.     cout << "thread end\n";
  68. }

  • define 定义后，sigint后#undef重新#define无效

    • define在编译时已经完成，运行时重新define无法更新到code
  • thread t[]中
    • this_thread::get_id()取得的是主线程id
    • vector[thread] t[]中，push_back一个thread可以正常获取Id