Hi Richard,
In the RPC server sample code, there is a line like this:
kj::NEVER_DONE.wait(waitScope);
This waits forever, running the event loop.
If you don't want the loop to run forever, the trick is to wait on a
promise that resolves at some point. For instance, you could create one:
auto [promise, fulfiller] = kj::newPromiseAndCrossThreadFulfiller();
promise.wait(waitScope);
Now, some other thread can call `fulfiller->fulfill()` to cause the
`promise.wait()` to return.
It would also be possible to make the KJ event loop run in the same thread
as ASIO, but this would indeed be a lot of work -- you would essentially
have to implement the KJ I/O interfaces in terms of ASIO, instead of using
UnixEventPort.
-Kenton
On Sun, Oct 29, 2023 at 3:29 PM Richard Hacker <[email protected]> wrote:
> Hello
>
> while EzRpcServer is a very easy two liner to use on its own (see
> ez-rpc.h), it is daunting to use RPC outside this context.
>
> My application is a data collection agent. While it is gathering data
> from its sources as a TCP client, at the same time it also serves this
> data to other clients connecting to it using capnp RPC. It uses ASIO as
> an event loop, but the problem would not change when using kj's event
> loop. To detach the data collector from the RPC server, I want to launch
> the RPC server in a thread of its own.
>
> The problem I am facing is how to shut down the RPC server thread from
> listening and its (long running) clients explicitly so that the main
> thread can join() the RPC thread. While EzRpcServer implementation is
> very short, I have no clue as to where I should start.
>
> Since the RPC server is running in a thread of its own, it can run its
> own EventPort, although merging it into ASIO's event loop would be the
> silver bullet, but I guess quite an integrate task.
>
> In the long run, I would also like to use RPC Client from a Qt
> application, this time it should be running instde Qt's event loop, but
> that is another story.
>
> Any hints would be very welcome
>
> Mit freundlichem Gruß
>
> Richard Hacker
>
> --
> ------------------------------------------------------------------------
>
> Richard Hacker M.Sc.
> [email protected]
> Tel.: +49 201 / 36014-16
>
> Ingenieurgemeinschaft IgH
> Gesellschaft für Ingenieurleistungen mbH
> Nordsternstraße 66
> D-45329 Essen
>
> Amtsgericht Essen HRB 11500
> USt-Id.-Nr.: DE 174 626 722
> Geschäftsführung:
> - Dr.-Ing. Siegfried Rotthäuser
> - Dr. Sven Beermann, Prokurist
> Tel.: +49 201 / 360-14-0
> http://www.igh.de
>
> ------------------------------------------------------------------------
>
> --
> You received this message because you are subscribed to the Google Groups
> "Cap'n Proto" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/capnproto/c67b1261-d39c-4138-8feb-55f045236986%40igh.de
> .
>
--
You received this message because you are subscribed to the Google Groups
"Cap'n Proto" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/capnproto/CAJouXQndG%3DHQJLGgBA58fexnbA1BWCGsVyaQg0kKbBcE-OAWyQ%40mail.gmail.com.
