pingpong

#include <iostream>
#include <thread>
#include <mutex>
#include <condition_variable>

std::mutex m;
std::condition_variable ping_done;
std::condition_variable pong_done;

void bar(){
    std::unique_lock <std::mutex> lock(m);
    for(size_t i = 0; i < 500000; ++i) {
        ping_done.wait(lock);
        printf("pong\n");
        pong_done.notify_one();
    }
}

void foo(){
    std::unique_lock <std::mutex> lock(m);
    for(size_t i = 0; i < 500000; ++i) {
        printf("ping\n");
        ping_done.notify_one();
        pong_done.wait(lock);
    }
}



int main(int argc, char const *argv[]) {
    std::thread T1 (bar);
    T1.detach();
    std::thread T2 (foo);
    T2.join();
    return 0;
}