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
33struct grpc_channel;
34
35namespace grpc {
36namespace testing {
37class ChannelTestPeer;
38} // namespace testing
39
40std::shared_ptr<::grpc_impl::Channel> CreateChannelInternal(
41 const grpc::string& host, grpc_channel* c_channel,
42 std::vector<
43 std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
44 interceptor_creators);
45} // namespace grpc
46namespace grpc_impl {
47
48namespace 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.
52void ChannelResetConnectionBackoff(Channel* channel);
53} // namespace experimental
54
55/// Channels represent a connection to an endpoint. Created by \a CreateChannel.
56class 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 grpc::string GetLoadBalancingPolicyName() const;
69
70 /// Returns the service config in JSON form, or the empty string if
71 /// not available.
72 grpc::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 grpc::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 grpc::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 grpc::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

source code of include/grpcpp/channel_impl.h