Is it possible to terminate the work of a standard thread started inside its creator thread?

The standard C++ library does not provide a direct way to forcibly terminate a thread from outside or from within another thread. A thread should finish its work on its own, for example, based on a condition or a flag.

If a thread is started within the thread that created it, the usual ways to terminate the thread are:

• Flags or condition variables: the thread periodically checks the termination flag and exits properly.
• std::thread::join(): the calling thread waits for the child thread to finish.

Example:

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

std::atomic<bool> stopFlag(false);

void worker() {
    while (!stopFlag.load()) {
        std::this_thread::sleep_for(std::chrono::milliseconds(100));
        std::cout << "Working...\n";
    }
    std::cout << "Thread is terminating.\n";
}

int main() {
    std::thread t(worker);
    std::this_thread::sleep_for(std::chrono::seconds(1));
    stopFlag.store(true); // signal the thread to finish
    t.join();
    return 0;
}

Thus, the thread controls its own termination, and the external thread simply signals it.