Re: [libmicrohttpd] Protocol upgrade

[Markus Doppelbauer]

Hello,

Writing directly to the socket does not bother me. My problem

is: In order to use websockets we need a second

"select/poll/epoll" event loop (which is not that easy if you

don't want to pull in 'libev').

Would it be possible to register the socket to the MHD event

loop? So that MHD could tell me if data arrives?

Thanks a lot!

Markus

Am Sonntag, den 13.11.2016, 21:39 +0100 schrieb Christian Grothoff:

> On 11/13/2016 08:47 PM, Markus Doppelbauer wrote:
> > Hello,
> >
> > Is the "protocol upgrade" API finalized? 
>
>
> Let's say I have no intention of changing it dramatically.
>
> > I can live with that, but this
> > way I need a second event loop. I would prefer an API where the MHD
> > event loop waits for websocket-data and - if new data arrives - calls
> > a handler. Something like:
> >
> > MHD_SocketHandle *
> > MHD_create_response_for_upgrade(
> >     MHD_UpgradeDataArrivedHandler read_handler,  // when data is
> > available
> >     MHD_UpgradeSocketClosedHandler close_handler ); // when socket is
> > closed
> > void
> > MHD_upgrade_write( MHD_SocketHandle *handle, void *data, size_t size );
> > void
> > MHD_upgrade_close( MHD_SocketHandle *handle );
>
>
> This doesn't work for various reasons. You can't just "write" like that
> due to flow control.  Similarly, MHD can't just read and call you like
> this, as your application might not be able to handle the data rate (and
> if your application blocks processing the data, that'd block MHD
> processing other activities in most threading modes).  So in the
> interest of keeping the API simple, giving you a socket is really the
> best option IMO.
>
> Happy hacking!
>
> Christian