std :: this_thread

this_thread 包装了一组可以访问当前线程信息的函数

functions

1、get_id()      获取当前线程的id。

// thread::get_id / this_thread::get_id#include <iostream>       // std::cout#include <thread>         // std::thread, std::thread::id, std::this_thread::get_id#include <chrono>         // std::chrono::seconds std::thread::id main_thread_id = std::this_thread::get_id();void is_main_thread() {  if ( main_thread_id == std::this_thread::get_id() )    std::cout << "This is the main thread.\n";  else    std::cout << "This is not the main thread.\n";}int main() {  is_main_thread();  std::thread th (is_main_thread);  th.join();}

输出结果

This is the main thread.This is not the main thread.

2、yield()

调用线程放弃执行，回到准备状态，重新分配cpu资源。所以调用该方法后，可能执行其他线程，也可能还是执行该线程

// this_thread::yield example#include <iostream>       // std::cout#include <thread>         // std::thread, std::this_thread::yield#include <atomic>         // std::atomicstd::atomic<bool> ready (false);void count1m(int id) {  while (!ready) {             // wait until main() sets ready...    std::this_thread::yield();  }  for (volatile int i=0; i<1000000; ++i) {}  std::cout << id;}int main (){  std::thread threads[10];  std::cout << "race of 10 threads that count to 1 million:\n";  for (int i=0; i<10; ++i) threads[i]=std::thread(count1m,i);  ready = true;               // go!  for (auto& th : threads) th.join();  std::cout << '\n';  return 0;}

输出结果

race of 10 threads that count to 1 million...6189370542

3、template <class Clock, class Duration>
       void sleep_until (const chrono::time_point<Clock,Duration>& abs_time);
阻塞调用线程，一直到指定事件

// this_thread::sleep_for example#include <iostream>       // std::cout#include <iomanip>        // std::put_time#include <thread>         // std::this_thread::sleep_until#include <chrono>         // std::chrono::system_clock#include <ctime>          // std::time_t, std::tm, std::localtime, std::mktimeint main() {  using std::chrono::system_clock;  std::time_t tt = system_clock::to_time_t (system_clock::now());  struct std::tm * ptm = std::localtime(&tt);  std::cout << "Current time: " << std::put_time(ptm,"%X") << '\n';  std::cout << "Waiting for the next minute to begin...\n";  ++ptm->tm_min; ptm->tm_sec=0;  std::this_thread::sleep_until (system_clock::from_time_t (mktime(ptm)));  std::cout << std::put_time(ptm,"%X") << " reached!\n";  return 0;}

输出结果

Current time: 11:52:36Waiting for the next minute to begin...11:53:00 reached!

4、template <class Rep, class Period>
       void sleep_for (const chrono::duration<Rep,Period>& rel_time);
阻塞调用线程，一直到指定时间段后。

// this_thread::sleep_for example#include <iostream>       // std::cout#include <thread>         // std::this_thread::sleep_for#include <chrono>         // std::chrono::seconds int main() {  std::cout << "countdown:\n";  for (int i=10; i>0; --i) {    std::cout << i << '\n';    std::this_thread::sleep_for (std::chrono::seconds(1));  }  std::cout << "Lift off!\n";  return 0;}

输出结果

countdown:10987654321Lift off!