advanced_usage.md

Advanced Usage

For basic usage, see tutorial in ../README.md.

Run multi stubs in one thread

Work in progress...

auto cq = std::make_shared<CQueueForNext>();
Svc1::Stub stub1(channel, cq);
Svc2::Stub stub2(channel, cq);
Run(cq);

Run a stub in multi threads

auto f1 = std::async(async, [stub]() { stub.Run(); }
auto f2 = std::async(async, [stub]() { stub.Run(); }

Mix sync and async stub calls

Stub uses an internal completion queue for async calls, and instantiate a completion queue for each sync operations, so Stub can mix sync and async calls.

  ...
  auto f = std::async(std::launch::async, [&stub]() { 
    stub.Run();
  });

  Point point = MakePoint(0,0);
  stub.AsyncGetFeature(point);
  
  Feature feature;
  Status status = stub.SyncGetFeature(point, &feature);
  ...

Set default error callback

Use ServiceStub::SetErrorCallback() to set a default error callback for this stub.

RouteGuide::Stub stub(channel);
stub.SetErrorCallback([](const Status& status) {
	cout << "RouteGuide: " << status.GetDetails() << endl;
});

Use ServiceStub::SetDefaultErrorCallback() to set a default error callback for all the new stubs.

ServiceStub::SetDefaultErrorCallback([](const Status& status) {
	cout << status.GetDetails() << endl;
});
Stub1 stub1(channel);
Stub2 stub2(channel);

Note: SetErrorCallback() and SetDefaultErrorCallback() are not thread-safe.

Timeout RPC calls

• Set timeout on channel

   ChannelSptr channel(new Channel("localhost:50051"));
   Stub stub(channel);
   channel->SetCallTimeoutMs(1000);  // 1 second
   stub->SyncSayHello();

• Set timeout on stub

   Stub stub(channel);
   stub.SetCallTimeoutMs(1000);

• Set timeout on call

  • To be implemented
  • Use ClientContext