拦截C ++线程

Question

所以我希望能够在C ++中运行线程中处理信号。我写了以下代码

#include <iostream>
#include <thread>
#include <vector>
#include <mutex>
#include <chrono>
#include <csignal>
using namespace std;

mutex mtx;

void signal_handle(int signal) {
    mtx.lock();
        cout << "Signal intercepted by thread " << std::this_thread::get_id() 
            << endl;
    mtx.unlock();

    std::this_thread::sleep_for(std::chrono::seconds(1));
}

void thread_func() {
    std::signal(SIGUSR1, signal_handle);

    while(true) {
        std::this_thread::sleep_for(std::chrono::seconds(2));

        mtx.lock();
            cout << "Thread number looping " << std::this_thread::get_id() << endl;
        mtx.unlock();
    } 
}

void signalling_func() {
    while (true) {
        std::this_thread::sleep_for(std::chrono::seconds(3));
        std::raise(SIGUSR1);
    }
}

int main() {
    vector<thread> threads;
    for (int i = 0; i < 5; ++i) {
        threads.push_back(thread(thread_func));
    }

    thread(signalling_func).detach();

    for (auto& th : threads) {
        th.join();
    }

    return 0;
}

信号永远不会由我创建的任何线程处理。我假设它是由主线程处理的。有什么方法可以表明我自己的线程吗？