gRPC-haskell/examples/hellos/hellos-cpp/hellos_client.cc
Joel Stanley 096d399b30 MONAPP-1035: Fix errant hang on metadata exchange in Haskell client-side bidirectional streaming (#70)
* (wip) Change ClientRWHandler to use an IO action for metadata acqui

* Demonstrate placement of WaitForInitialMetadata() in hellos_client

* Make hellos cpp server always send metadata first, for now

* Show getMD placement in haskell hellos-client

* Add prelim bidi metadata exchange behavior tweaks to line up with C++ API conventions
2016-08-15 12:55:40 -05:00

147 lines
4.3 KiB
C++

#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <grpc++/grpc++.h>
#include "hellos.grpc.pb.h"
using grpc::Channel;
using grpc::ClientContext;
using grpc::ClientReader;
using grpc::ClientWriter;
using grpc::ClientReaderWriter;
using grpc::Status;
using hellos::SSRqt;
using hellos::SSRpy;
using hellos::CSRqt;
using hellos::CSRpy;
using hellos::BiRqtRpy;
using hellos::Hellos;
static void Die(const std::string& msg) {
std::cerr << "Fatal error: " << msg << std::endl;
exit(1);
}
static void CheckRPCStatus(const std::string& ctx, Status status) {
if (status.ok()) {
std::cout << ctx << ": RPC successful." << std::endl;
} else {
std::cout << ctx << ": Got failed status code: " << status.error_code() << std::endl;
std::cout << ctx << ": Got failed status msg: " << status.error_message() << std::endl;
Die(ctx + ": RPC failed");
}
}
class HellosClient {
public:
HellosClient(std::shared_ptr<Channel> channel)
: stub_(Hellos::NewStub(channel)) {}
void DoHelloSS(const std::string& name, unsigned n) {
SSRqt rqt;
rqt.set_name(name);
rqt.set_num_replies(n);
SSRpy rpy;
ClientContext ctx;
std::unique_ptr<ClientReader<SSRpy> > reader(stub_->HelloSS(&ctx, rqt));
unsigned rpyCnt = 0;
while (reader->Read(&rpy)) {
++rpyCnt;
std::string ex("Hello there, " + name + "!");
if (rpy.greeting() != ex) {
Die("DoHelloSS/rpy: expected payload '" + ex +
"', got '" + rpy.greeting() + "'");
}
}
Status status = reader->Finish();
CheckRPCStatus("DoHelloSS", status);
if (rpyCnt != n)
Die("DoHelloSS/cnt: expected " + std::to_string(n) +
"replies, got " + std::to_string(rpyCnt));
}
void DoHelloCS(const std::string& pay, unsigned n) {
CSRqt rqt;
rqt.set_message(pay);
CSRpy rpy;
ClientContext ctx;
std::unique_ptr<ClientWriter<CSRqt> > writer(stub_->HelloCS(&ctx, &rpy));
for (unsigned i = 0; i < n; ++i) {
if (!writer->Write(rqt)) {
// Broken stream
break;
}
}
writer->WritesDone();
Status status = writer->Finish();
CheckRPCStatus("DoHelloCS", status);
if (rpy.num_requests() != n)
Die("DoHelloCS/cnt: expected request count " + std::to_string(n) +
", got " + std::to_string(rpy.num_requests()));
}
void DoHelloBi(const std::string& pay, unsigned n) {
BiRqtRpy rqt;
rqt.set_message(pay);
ClientContext ctx;
std::shared_ptr<ClientReaderWriter<BiRqtRpy, BiRqtRpy> > strm(stub_->HelloBi(&ctx));
// strm->WaitForInitialMetadata();
// Spawn a writer thread which sends rqt to the server n times.
std::thread writer([strm,rqt,n]() {
for(unsigned i = 0; i < n; ++i) {
strm->Write(rqt);
}
strm->WritesDone();
});
// Concurrently, read back echo'd replies from the server until there are no
// more to consume; ensure we get the expected number of responses after
// there's nothing left to read.
BiRqtRpy rpy;
unsigned rpyCnt = 0;
while(strm->Read(&rpy)) {
if (rpy.message() != pay)
Die("DoHelloBi/rpy: expected payload '" + pay +
"', got '" + rpy.message() + "'");
++rpyCnt;
}
writer.join();
Status status = strm->Finish();
CheckRPCStatus("DoHelloBi", status);
if (rpyCnt != n)
Die("DoHelloBi/cnt: expected reply count " + std::to_string(n) +
", got " + std::to_string(rpyCnt));
}
private:
std::unique_ptr<Hellos::Stub> stub_;
};
int main(int argc, char** argv) {
// Instantiate the client. It requires a channel, out of which the actual RPCs
// are created. This channel models a connection to an endpoint (in this case,
// localhost at port 50051). We indicate that the channel isn't authenticated
// (use of InsecureChannelCredentials()).
HellosClient hellos(grpc::CreateChannel(
"localhost:50051", grpc::InsecureChannelCredentials()));
const unsigned n = 100000;
std::cout << "-------------- HelloSS --------------" << std::endl;
hellos.DoHelloSS("server streaming mode", n);
std::cout << "-------------- HelloCS --------------" << std::endl;
hellos.DoHelloCS("client streaming payload", n);
std::cout << "-------------- HelloBi --------------" << std::endl;
hellos.DoHelloBi("bidi payload", n);
return 0;
}