async module with c++ v8 for node js,error associated with the types in the structure

Question

I am writing asynchronous module, but I can not pass an array structure. Please help. That's the error appears. How to avoid it? error C2440: '=' : cannot convert from 'v8::Handle' to 'v8::Array *'

struct Async {
    Handle<v8::Array> result;
}
void wmiWorker(uv_work_t* req) {
    Async* request = (Async*)req->data;
    *(request->result) = getArray(1);
}
Handle<Array> getArray(int x) {

  HandleScope handle_scope;
  Handle<Array> array = Array::New(3);

  if (array.IsEmpty())
    return Handle<Array>();

  array->Set(0, Integer::New(x));
  return handle_scope.Close(array);
}

loganfsmyth · Accepted Answer · 2013-06-13 15:49:06Z

1

Your line

*(request->result) = getArray(1);

assigns a Handle<Array> to *(Handle<Array>) (which means Array*), which is not valid.

However even with that, there is an important factor that you are not taking into account. Your wmiWorker function is running in a separate thread. NodeJS and V8 only allow a single thread of execution for JS, and what you are attempting to do is create a JS array inside of a separate thread.

Instead you will need to create a vector or something, and generate the V8 array from that inside of the work callback's after_work callback.

edited Jun 13, 2013 at 15:49

answered Jun 7, 2013 at 15:19

loganfsmyth

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5 Comments

Yaroslav L. Over a year ago

I did as you said, but did not work. That is, result now Persistent, array is Local <Array>. error C2679: binary '=' : no operator found which takes a right-hand operand of type 'v8::Handle<T>' (or there is no acceptable conversion)

Yaroslav L. Over a year ago

Another feature. I do not understand why she proshodit. If you declare a function wmiWorker Local <Array> array = Array :: New (1), all compiled, the cout << "str"; in this function is not called. If you take away - all works. What's the problem?

loganfsmyth Over a year ago

@YaroslavL. Woops, fixed. For your second question, can you post an example in your question? I don't 100% follow what you are asking.

Yaroslav L. Over a year ago

Local <Array> ABC = Array::New(1); If ABC announced in wmiWorker (that is, if I announced it there), then the test case does not output anything (but compiles and does not throw an error), if you remove from there ABC, print all you need (aaaETO A BLA undefined ETO B BLA ['ccc']) pastie.org/8028942

loganfsmyth Over a year ago

@YaroslavL. I updated my answer with what I believe your issue to be.

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