src/cpp/stream/stream_context.h

/*
 *
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#ifndef __GRPCPP_INTERNAL_STREAM_STREAM_CONTEXT_H__
#define __GRPCPP_INTERNAL_STREAM_STREAM_CONTEXT_H__

#include <condition_variable>
#include <mutex>
#include <thread>

#include <grpc++/status.h>
#include <grpc++/stream_context_interface.h>

namespace google {
namespace protobuf {
class Message;
}
}

struct grpc_event;

namespace grpc {
class ClientContext;
class RpcMethod;

class StreamContext : public StreamContextInterface {
 public:
  StreamContext(const RpcMethod& method, ClientContext* context,
                const google::protobuf::Message* request, google::protobuf::Message* result);
  ~StreamContext();
  // Start the stream, if there is a final write following immediately, set
  // buffered so that the messages can be sent in batch.
  void Start(bool buffered) override;
  bool Read(google::protobuf::Message* msg) override;
  bool Write(const google::protobuf::Message* msg, bool is_last) override;
  const Status& Wait() override;
  void FinishStream(const Status& status, bool send) override;

  const google::protobuf::Message* request() override { return request_; }
  google::protobuf::Message* response() override { return result_; }

 private:
  void PollingLoop();
  bool BlockingStart();
  bool is_client_;
  const RpcMethod* method_;         // not owned
  ClientContext* context_;          // now owned
  const google::protobuf::Message* request_;  // not owned
  google::protobuf::Message* result_;         // not owned

  std::thread cq_poller_;
  std::mutex mu_;
  std::condition_variable invoke_cv_;
  std::condition_variable read_cv_;
  std::condition_variable write_cv_;
  std::condition_variable finish_cv_;
  grpc_event* invoke_ev_;
  // TODO(yangg) make these two into queues to support concurrent reads and
  // writes
  grpc_event* read_ev_;
  grpc_event* write_ev_;
  bool reading_;
  bool writing_;
  bool got_read_;
  bool got_write_;
  bool peer_halfclosed_;
  bool self_halfclosed_;
  bool stream_finished_;
  bool waiting_;
  Status final_status_;
};

}  // namespace grpc

#endif  // __GRPCPP_INTERNAL_STREAM_STREAM_CONTEXT_H__