Using conditional variable and mutex

// Using conditional variable and mutex
void function_1() {
    int count = 10;
    while (count > 0) {
        std::unique_lock<mutex> locker(mu);
        q.push_front(count);
        locker.unlock();
        cond.notify_one();  // Notify one waiting thread, if there is one.
        std::this_thread::sleep_for(chrono::seconds(1));
        count--;
    }
}

void function_2() {
    int data = 0;
    while ( data != 1) {
        std::unique_lock<mutex> locker(mu);
        cond.wait(locker, [](){ return !q.empty();} );  // Unlock mu and wait to be notified
            // relock mu
        data = q.back();
        q.pop_back();
        locker.unlock();
        cout << "t2 got a value from t1: " << data << endl;
    }
}

int main() {
    std::thread t1(function_1);
    std::thread t2(function_2);
    t1.join();
    t2.join();
    return 0;
}