什么时候调用 std::thread 析构函数？

Question

我知道 std::thread 析构函数在主出口或线程对象超出范围时调用。

但是当它调用的函数执行完毕时它是否也被销毁了？
如果不是这样的帖子怎么办，我还能join()吗？

Answer 1

But is it also destroyed when a function that it is calling is done executing? If not what happens to such a thread, can I still join() it?

不，它没有被销毁，但被标记为 joinable()。所以是的，你仍然可以 join() 它。

否则从你的问题标题 ("When is std::thread destructor called?") 和你在 post

中所说的

I know that std::thread destructors are called on main exit, or when a thread object goes out of scope.

这与任何其他实例一样：当实例超出范围时调用析构函数，或者在动态分配实例的情况下调用 delete。

这是一个小示例代码

#include <thread>
#include <iostream>
#include <chrono>

using namespace std::chrono_literals;

void foo() {
    std::cout  << "Hello from thread!" << std::endl;
}

int main() { 
    std::thread t(foo);
    std::this_thread::sleep_for(1s);
    std::cout << "t.joinable() is " << t.joinable() << std::endl;
    t.join();
}

输出为

Hello from thread!
t.joinable() is 1

看到了live.

什么时候调用 std::thread 析构函数？

When is std::thread destructor called?

c++

stdthread