Call ClientReader's Finish() function ahead of schedule will cause program block forever

[xiaona...@gmail.com]

Hi all,

I am using "A server-side streaming RPC where the client sends a request to the server and gets a stream to read a sequence of messages back. " mode:  

rpc transaction(request) returns (stream response) {}

My current Client cod's logic is: if find response message format error, doesn't receive the rest message, call the ClientReader's Finish() function:

while (reader->Read(&response)) {

      if (response is error) {

break;

 }

}

reader->Finish();

The Server's code is simple, just for-loop write all responses:  

for (...) {

writer->Write(response); 

} 

But I find if Client doesn't read all responses, the  "reader->Finish();" will block forever. So my current solution is even the response has error, Client still need to 

read all responses.  

So my question is what is the correct method to only process half of the stream response? Must read all responses? 

Thanks very much in advance!

Best Reagrds

Nan Xiao

[Carl Mastrangelo]

What language are you using?

[Nan Xiao]

Hi Carl,

C++, thanks!
Best Regards
Nan Xiao

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[Vijay Pai]

The confusion comes from the name, I think. "Finish" is alerting the system that your code is ready to get the status and isn't going to do anything more to the stream, but it isn't forcibly shutting down the stream. If you want to forcibly shut down the stream, just call a TryCancel on the ClientContext object. 

On Wednesday, September 27, 2017 at 11:13:18 PM UTC-7, xiaona...@gmail.com wrote: