c++ - 如何多次锁定互斥锁？

Question

例如:

std::mutex g_mutex;


void Function2()
{
    std::lock_guard<std::mutex> lock(g_mutex);

    //do something not thread safe

    printf("in function2: thread: 0x%08X\n", std::this_thread::get_id().hash());
}

void Function1()
{
    std::lock_guard<std::mutex> lock(g_mutex);

    //do something not thread safe

    printf("in function1: thread: 0x%08X\n", std::this_thread::get_id().hash());

    Function2();
}


int main()
{

    std::thread t1([](){

        Function1();

    });
    t1.join();

    getchar();
    return 0;
}

我想通过锁定一个互斥锁使 Function1 和 Function2 线程安全，但它抛出运行时错误:

R6010 -abord() has been called

是否可以仅使用一个互斥锁来做到这一点？我不想创建另一个互斥体

Answer 1

我会使用该函数的解锁版本，并通过在结构/类中将其设为私有(private)来隐藏它:

struct Functions {
public:
    static void f2()
    {
        std::lock_guard<std::mutex> lock(g_mutext);
        f2_i();
    }

    static void f1()
    {
        std::lock_guard<std::mutex> lock(g_mutext);

        //do something not thread safe
        printf("in function1: thread: 0x%08X\n", std::this_thread::get_id().hash());

        f2_i();
    }

private:
    static void f2_i()
    {
        //do something not thread safe
        printf("in function2: thread: 0x%08X\n", std::this_thread::get_id().hash());
    }
};