0.案例代码

先看下面一个例子：

#include <iostream>
#include <thread>

void ThreadMain()
{
	std::cout << "begin sub thread:" << std::this_thread::get_id()<<std::endl;
	for (int i = 0; i < 10; i++)
	{
		std::cout << "thread in "<< i << std::endl;
		std::this_thread::sleep_for(std::chrono::seconds(1));
	}
	std::cout << "end sub thread:" << std::this_thread::get_id() << std::endl;
}

int main()
{
	std::cout << "the main ID:" << std::this_thread::get_id() << std::endl;
	std::thread th(ThreadMain);//线程创建启动
	std::cout << "begin sub thread" << std::endl;
	th.join();//阻塞等待子线程退出
	std::cout << "end sub thread" << std::endl;
	return 0;
}

1.案例代码分析

从执行结果来看，线程在std::thread th(ThreadMain)的时候就已经启动了，join只不过相当于堵塞等待的作用，