atomic.cpp #1

#include <atomic>
#include <stdio.h>
#include <thread>

std::atomic<int> foo { 0 };
std::atomic<int> bar { 0 };

void set_foo(int x)
{
    foo = x;
}

void copy_bar()
{
    while (foo == 0) {
        std::this_thread::yield();
    }
    bar = foo.load();
}

void print_bar()
{
    while (bar == 0) {
        std::this_thread::yield();
    }
    printf("%d\n", bar.load());
}

int main(int argc, const char **argv)
{
    std::thread f(print_bar);
    std::thread s(set_foo, 10);
    std::thread t(copy_bar);

    f.join();
    s.join();
    t.join();

    return 0;
}