将类的成员函数传递给pthread_cleanup_push（）时，没有匹配的函数调用

Question

When I try to pass my function cleanup_thread() to pthread_cleanup_push() :

pthread_cleanup_push(cleanup_thread, arg);

I get the following compiler error:

 error: no matching function for call to ‘__pthread_cleanup_class::__pthread_cleanup_class(<unresolved overloaded function type>, void*&)’

I guess its because void cleanup_thread(void *arg) is a member function of my class and therefor has the this pointer as first argument. So the signature of the function cleanup_thread() does not match. How can I tell pthread_cleanup_push() to use my member function cleanup_thread() ?

Answer 1

The easiest solution is probably to make the function a static member function, and pass the instance pointer as the argument.

Something like this:

struct data_struct
{
    some_class* instance;
    pthread_t   thread_id;
};

class some_class
{
public:
    ...

    static void cleanup_thread(void* arg)
    {
        data_struct* ptr = reinterpret_cast<data_struct*>(arg);
        ptr->instance->private_cleanup_thread();
        delete ptr;
    }

private:
    void private_cleanup_thread()
    {
        ...
    }
};

...

some_class* some_class_ptr = new some_class;

...

data_struct* data_ptr = new data_struct;
data_ptr->instance = some_class_ptr;
data_ptr->thread_id = some_thread_id;

pthread_cleanup_push(&some_class::cleanup_thread, data_ptr);