Using libuv inside classes

I am trying to write a nodejs bindings for a C++ library and I seem to have hit a roadblock.

I am working on trying to make all the calls to the C++ library asynchronous and thats why I am using libuv. I am basically following this tutorial.

I want to be able to call class member functions from libuv's uv_queue_work. Have a look at this code --

class test {
  private:
    int data;
    void Work(uv_work_t *req);
    void After(uv_work_t *req);
  public:
    Handle<Value> Async(const Arguments& args) {
      HandleScope scope;
      Local<Function> callback = Local<Function>::Cast(args[0]);
      int status = uv_queue_work(uv_default_loop(), **something**, Work, After);
      assert(status == 0);
      return Undefined();
    }
};

Basically I expect the Work and After functions to work on the data element of the class. However this doesnt seem to work. I have tried typecasting the pointers to Work and After after from type void test::(*)(uv_work_t*) to void (*)(uv_work_t*). But that also doesnt seem to work.

Could you guys give me some tips on how to work around this??

So as you've realized, you cannot call the member functions directly.

The second argument "something" is of type uv_work_t, which has a member "void* data".

What you will need to do is create static methods inside your class for "Work" and "After", create a uv_work_t structure, and assign data to "this".

Once that is done inside your static "Work" and "After" methods you do a static cast on "req->data" (To your class type) and then call your member functions.

For example:

uv_work_t* baton = new uv_work_t();
baton->data = this;
int status = uv_queue_work(uv_default_loop(), baton, StaticWork, StaticAfter);

And then in the static methods

test* myobj = static_cast<test>(req->data);
myobj->Work();

And similar code for the StaticAfter function

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