[grpc-c++] gRPC polling for incoming packets from multiple sockets

[Maysam Mehraban]

Hello,

I am looking into possibility of listening on different sockets at once. To handle multiple socket connection at the same fd_set can be used in Linux. I have seen that gRPC also support this functionality with having epoll based pollset.

https://github.com/grpc/grpc/blob/18df25228cfa1f97fc5cca9176fbaef64c0e4221/doc/epoll-polling-engine.md

I intend to call different services in async mode and providing a service at the same time. Therefore, I was thinking about having a poll-set consist of client sockets waiting for async responses and server sockets. It seems to be possible in gRPC. I haven't been able to find anything in gRPC API that exposes construction of a poll-set.

Hence, my question is how to use this capability of gRPC?

Does gRPC manages this automatically? In that case how can I wait for incoming messages?

Many Thanks in advance.

Best// Maysam

[ista.s...@gmail.com]

Hey!

I am also looking into the same kind of handling mechanism to leverage gRPC promises one step forward 

but unfortunately there is no such example or explanations in the web that I found (:-

It's really appreciated if anyone from Core team can reply something here or update the doc with examples that really shows it.

Looking forward -- waiting for a reply ! Thanks.

Regards

ista

Email :- ista.s...@gmail.com

[Muxi Yan]

Hi! If you are using gRPC C++, you can create server and client calls on the same completion queue so that when you wait for event on that completion queue you wait for those from both sides.

[Ista Ranjan Samanta]

Hi,

Thanks a lot for providing the accomplish able approach towards it. Yes, I am also using C++ gRPC. 

I was carefully following this concrete example -- https://github.com/grpc/grpc/tree/master/examples/cpp/helloworld On the server you get a completion queue in this line -- auto cq = builder.AddCompletionQueue();   // Line no 59 in greeter_async_server.cc file

On the client side,you provide a completion queue -- CompletionQueue cq;    //Line no 58 in greeter_async_client.cc file

So, do you mean to use the same cq ? Just to be super clear to understand your comment. Thanks.

Regards

ista

[Yang Gao]

Yes. A ServerCompletionQueue is a CompletionQueue and you can use it for client events as well.