@Nathan, you probably know this stuff better than me now days, but
couldn't @m1k3l just use uv_queue_work() to enqueue the call to a
third-party library?
(mainly due to the fact that uv_queue_work appears to be similar to
eio_custom.)
– Micheil
On 16/03/2012, at 9:56 PM, m1k3l wrote:
> Thanks! I got it to work. Here is what I did, let me know if this correct.
>
> struct Baton {
> Persistent<Function> callback;
> int error;
> std::string error_message;
> uv_async_t async;
>
> // Custom data
> Persistent<Object> data;
> };
>
> JS_METHOD(Event::setCallback) {
> Baton *baton=new Baton();
> baton->callback=Persistent<Function>::New(Local<Function>::Cast(args[0]));
>
> uv_async_init(uv_default_loop(), &baton->async, After_cb); // tell UV to
> call After_cb() async
>
> baton->async.data=baton;
>
> call_driver(..., driver_cb, baton);
> }
>
>
> void driver_cb (int status, void *user_data)
> {
> ...
> uv_async_send(((Baton*) user_data)->async); // wakes up UV to call After_cb()
> }
>
> void After_cb(uv_async_t *handle, int status) {
> Baton *baton = static_cast<Baton*>(handle->data);
> uv_close((uv_handle_t*) &baton->async,NULL); // necessary otherwise UV will
> block
> ...
> baton->callback->Call(v8::Context::GetCurrent()->Global(), 1, argv); // call
> the JS callback method as usual
> ...
> baton->callback.Dispose(); // delete the baton
> baton->data.Dispose();
> delete baton;
> }
>
>
>
> On Friday, March 16, 2012 10:48:42 AM UTC-7, Nathan Rajlich wrote:
> I'm pretty sure this is what uv_async_t, uv_async_send and friends are for,
> but somebody correct be if I am wrong.
>
> On Fri, Mar 16, 2012 at 10:22 AM, m1k3l <[email protected]> wrote:
> Hi,
>
> I have a native method running in its own thread and calling a callback to
> post its status. The callback has some user data that I'd like to post to JS.
> Since the callback is running in a different thread than v8, I can't use any
> v8 method to call a JS callback function. So I wonder if there is a way to
> use some persistent objects to do that?
>
> One solution I found is to use queue the native method using libuv. This way,
> I can use a busy wait in uv's Work callback method until my native method's
> callback is called. Then uv's Work callback proceed and I can use uv's After
> callback to call the JS callback method, as usual.
>
> While this seems to work, it still looks like very hack-ish. Is there a
> better solution/pattern?
>
> Thanks
>
>
> On Friday, March 16, 2012 10:48:42 AM UTC-7, Nathan Rajlich wrote:
> I'm pretty sure this is what uv_async_t, uv_async_send and friends are for,
> but somebody correct be if I am wrong.
>
> On Fri, Mar 16, 2012 at 10:22 AM, m1k3l <[email protected]> wrote:
> Hi,
>
> I have a native method running in its own thread and calling a callback to
> post its status. The callback has some user data that I'd like to post to JS.
> Since the callback is running in a different thread than v8, I can't use any
> v8 method to call a JS callback function. So I wonder if there is a way to
> use some persistent objects to do that?
>
> One solution I found is to use queue the native method using libuv. This way,
> I can use a busy wait in uv's Work callback method until my native method's
> callback is called. Then uv's Work callback proceed and I can use uv's After
> callback to call the JS callback method, as usual.
>
> While this seems to work, it still looks like very hack-ish. Is there a
> better solution/pattern?
>
> Thanks
>
