write_x_and_read_y.c 的 C++ 版本

write_x_and_read_y.cpp

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

using namespace std::literals;

std::atomic_int flag{ 0x00 };
std::atomic_int x{ 0 }, y{ 0 };

void f1()
{
    while (true) {
        while (!(flag & 0b10));
        
        x.store(11, std::memory_order_relaxed);
        // std::atomic_thread_fence(std::memory_order_seq_cst);
        int v = y.load(std::memory_order_relaxed);
        printf("%i ", v);

        flag.fetch_and(0b01);
    }
}

void f2()
{
    while (true) {
        while (!(flag & 0b01));
        
        y.store(22, std::memory_order_relaxed);
        // std::atomic_thread_fence(std::memory_order_seq_cst);
        int v = x.load(std::memory_order_relaxed);
        printf("%i ", v);
        
        flag.fetch_and(0b10);
    }
}

int main()
{
    std::thread t1(f1), t2(f2);

    while (true) {
        x = 0, y = 0;
        flag = 0b11;

        // std::this_thread::sleep_for(1ms);

        while (flag);

        printf("\n");
        fflush(stdout);
    }

    t1.join();
    t2.join();
}

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