agrpc
Build an elegant GRPC async interface with C++20 coroutine and libunifex (target for C++23 executor).
Get started
mkdir build && cd build
conan install ..
cmake -DCMAKE_CXX_FLAGS:STRING=-fcoroutines ..
cmake --build .Work in progress
One glance:
| native async grpc | agrpc |
class CallData {
public:
void Proceed() {
if (status_ == CREATE) {
status_ = PROCESS;
service_->RequestSayHello(&ctx_, &request_,
&responder_,
cq_, cq_, this);
} else if (status_ == PROCESS) {
new CallData(service_, cq_);
std::string prefix("Hello ");
reply_.set_message(prefix + request_.name());
status_ = FINISH;
responder_.Finish(reply_, Status::OK, this);
} else {
GPR_ASSERT(status_ == FINISH);
delete this;
}
}
private:
// ...
enum CallStatus { CREATE, PROCESS, FINISH };
CallStatus status_{CREATE}; // The current serving state.
};
void HandleRpcs() {
new CallData(&service_, cq_.get());
void* tag; // uniquely identifies a request.
bool ok;
while (true) {
GPR_ASSERT(cq_->Next(&tag, &ok));
GPR_ASSERT(ok);
static_cast<CallData*>(tag)->Proceed();
}
} |
agrpc::GrpcContext grpc_context{builder.AddCompletionQueue()};
while (true) {
grpc::ServerContext server_context;
helloworld::HelloRequest request;
grpc::ServerAsyncResponseWriter<helloworld::HelloReply> writer{
&server_context};
bool request_ok = co_await agrpc::AsyncRequest(
grpc_context.get_scheduler(),
&helloworld::Greeter::AsyncService::RequestSayHello,
service, server_context, request, writer);
if (!request_ok)
co_return;
helloworld::HelloReply response;
response.set_message("Hello " + request.name());
co_await agrpc::AsyncFinish(grpc_context.get_scheduler(), writer,
response, grpc::Status::OK);
} |
Benchmark
1 CPU server
| name | req/s | avg. latency | 90 % in | 95 % in | 99 % in | avg. cpu | avg. memory |
|---|---|---|---|---|---|---|---|
| cpp_agrpc | 35385 | 26.74 ms | 39.48 ms | 49.60 ms | 64.11 ms | 92.43% | 28.78 MiB |
| cpp_grpc_st | 35364 | 26.03 ms | 48.25 ms | 58.39 ms | 72.63 ms | 80.95% | 21.57 MiB |
| cpp_grpc_mt | 35068 | 26.23 ms | 48.16 ms | 58.60 ms | 72.72 ms | 80.29% | 18.05 MiB |
| rust_tonic_st | 33407 | 25.96 ms | 54.54 ms | 60.15 ms | 68.41 ms | 66.22% | 15.34 MiB |
| dotnet_grpc | 32125 | 26.78 ms | 53.29 ms | 66.82 ms | 81.76 ms | 95.1% | 94.31 MiB |
| rust_tonic_mt | 31428 | 29.06 ms | 90.03 ms | 97.46 ms | 106.46 ms | 69.87% | 13.52 MiB |
| cpp_grpc_callback | 12283 | 80.54 ms | 103.30 ms | 107.25 ms | 178.37 ms | 100.27% | 406.88 MiB |
| go_grpc | 5600 | 176.37 ms | 306.34 ms | 397.40 ms | 598.96 ms | 100.41% | 44.02 MiB |
2 CPU server
| name | req/s | avg. latency | 90 % in | 95 % in | 99 % in | avg. cpu | avg. memory |
|---|---|---|---|---|---|---|---|
| rust_tonic_mt | 77236 | 11.97 ms | 30.99 ms | 44.78 ms | 68.00 ms | 191.33% | 17.42 MiB |
| cpp_agrpc | 72084 | 13.50 ms | 20.83 ms | 23.73 ms | 31.08 ms | 202.99% | 86.8 MiB |
| cpp_grpc_mt | 68099 | 14.18 ms | 34.95 ms | 39.29 ms | 45.88 ms | 203.08% | 61.64 MiB |
| dotnet_grpc | 63479 | 13.98 ms | 20.35 ms | 26.62 ms | 61.63 ms | 201.58% | 175.97 MiB |
| rust_tonic_st | 61962 | 15.83 ms | 19.73 ms | 21.05 ms | 24.13 ms | 102.46% | 16.32 MiB |
| cpp_grpc_st | 50593 | 19.47 ms | 23.59 ms | 25.26 ms | 29.66 ms | 102.15% | 19.53 MiB |
| cpp_grpc_callback | 29612 | 32.49 ms | 74.33 ms | 78.51 ms | 85.74 ms | 202.37% | 444.44 MiB |
| go_grpc | 12050 | 80.52 ms | 188.05 ms | 194.19 ms | 286.45 ms | 200.78% | 45.11 MiB |
Goal
Maybe something like C# interface.
public override async Task RouteChat(Grpc.Core.IAsyncStreamReader<RouteNote> requestStream,
Grpc.Core.IServerStreamWriter<RouteNote> responseStream,
Grpc.Core.ServerCallContext context)
{
while (await requestStream.MoveNext())
{
var note = requestStream.Current;
List<RouteNote> prevNotes = AddNoteForLocation(note.Location, note);
foreach (var prevNote in prevNotes)
{
await responseStream.WriteAsync(prevNote);
}
}
}