1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPCPP_CHANNEL_IMPL_H 20 #define GRPCPP_CHANNEL_IMPL_H 21 22 #include <memory> 23 24 #include <grpc/grpc.h> 25 #include <grpcpp/impl/call.h> 26 #include <grpcpp/impl/codegen/channel_interface.h> 27 #include <grpcpp/impl/codegen/client_interceptor.h> 28 #include <grpcpp/impl/codegen/completion_queue_impl.h> 29 #include <grpcpp/impl/codegen/config.h> 30 #include <grpcpp/impl/codegen/grpc_library.h> 31 #include <grpcpp/impl/codegen/sync.h> 32 33 struct grpc_channel; 34 35 namespace grpc { 36 namespace testing { 37 class ChannelTestPeer; 38 } // namespace testing 39 40 std::shared_ptr<::grpc_impl::Channel> CreateChannelInternal( 41 const std::string& host, grpc_channel* c_channel, 42 std::vector< 43 std::unique_ptr<experimental::ClientInterceptorFactoryInterface>> 44 interceptor_creators); 45 } // namespace grpc 46 namespace grpc_impl { 47 48 namespace experimental { 49 /// Resets the channel's connection backoff. 50 /// TODO(roth): Once we see whether this proves useful, either create a gRFC 51 /// and change this to be a method of the Channel class, or remove it. 52 void ChannelResetConnectionBackoff(Channel* channel); 53 } // namespace experimental 54 55 /// Channels represent a connection to an endpoint. Created by \a CreateChannel. 56 class Channel final : public ::grpc::ChannelInterface, 57 public ::grpc::internal::CallHook, 58 public std::enable_shared_from_this<Channel>, 59 private ::grpc::GrpcLibraryCodegen { 60 public: 61 ~Channel(); 62 63 /// Get the current channel state. If the channel is in IDLE and 64 /// \a try_to_connect is set to true, try to connect. 65 grpc_connectivity_state GetState(bool try_to_connect) override; 66 67 /// Returns the LB policy name, or the empty string if not yet available. 68 std::string GetLoadBalancingPolicyName() const; 69 70 /// Returns the service config in JSON form, or the empty string if 71 /// not available. 72 std::string GetServiceConfigJSON() const; 73 74 private: 75 template <class InputMessage, class OutputMessage> 76 friend class ::grpc::internal::BlockingUnaryCallImpl; 77 friend class ::grpc::testing::ChannelTestPeer; 78 friend void experimental::ChannelResetConnectionBackoff(Channel* channel); 79 friend std::shared_ptr<Channel> grpc::CreateChannelInternal( 80 const std::string& host, grpc_channel* c_channel, 81 std::vector<std::unique_ptr< 82 ::grpc::experimental::ClientInterceptorFactoryInterface>> 83 interceptor_creators); 84 friend class ::grpc::internal::InterceptedChannel; 85 Channel(const std::string& host, grpc_channel* c_channel, 86 std::vector<std::unique_ptr< 87 ::grpc::experimental::ClientInterceptorFactoryInterface>> 88 interceptor_creators); 89 90 ::grpc::internal::Call CreateCall(const ::grpc::internal::RpcMethod& method, 91 ::grpc_impl::ClientContext* context, 92 ::grpc_impl::CompletionQueue* cq) override; 93 void PerformOpsOnCall(::grpc::internal::CallOpSetInterface* ops, 94 ::grpc::internal::Call* call) override; 95 void* RegisterMethod(const char* method) override; 96 97 void NotifyOnStateChangeImpl(grpc_connectivity_state last_observed, 98 gpr_timespec deadline, 99 ::grpc_impl::CompletionQueue* cq, 100 void* tag) override; 101 bool WaitForStateChangeImpl(grpc_connectivity_state last_observed, 102 gpr_timespec deadline) override; 103 104 ::grpc_impl::CompletionQueue* CallbackCQ() override; 105 106 ::grpc::internal::Call CreateCallInternal( 107 const ::grpc::internal::RpcMethod& method, 108 ::grpc_impl::ClientContext* context, ::grpc_impl::CompletionQueue* cq, 109 size_t interceptor_pos) override; 110 111 const std::string host_; 112 grpc_channel* const c_channel_; // owned 113 114 // mu_ protects callback_cq_ (the per-channel callbackable completion queue) 115 grpc::internal::Mutex mu_; 116 117 // callback_cq_ references the callbackable completion queue associated 118 // with this channel (if any). It is set on the first call to CallbackCQ(). 119 // It is _not owned_ by the channel; ownership belongs with its internal 120 // shutdown callback tag (invoked when the CQ is fully shutdown). 121 ::grpc_impl::CompletionQueue* callback_cq_ = nullptr; 122 123 std::vector< 124 std::unique_ptr<::grpc::experimental::ClientInterceptorFactoryInterface>> 125 interceptor_creators_; 126 }; 127 128 } // namespace grpc_impl 129 130 #endif // GRPCPP_CHANNEL_IMPL_H 131