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 #include <grpcpp/channel.h>
20
21 #include <cstring>
22 #include <memory>
23
24 #include <grpc/grpc.h>
25 #include <grpc/slice.h>
26 #include <grpc/support/alloc.h>
27 #include <grpc/support/log.h>
28 #include <grpc/support/sync.h>
29 #include <grpc/support/time.h>
30 #include <grpcpp/client_context.h>
31 #include <grpcpp/completion_queue.h>
32 #include <grpcpp/impl/call.h>
33 #include <grpcpp/impl/codegen/call_op_set.h>
34 #include <grpcpp/impl/codegen/completion_queue_tag.h>
35 #include <grpcpp/impl/grpc_library.h>
36 #include <grpcpp/impl/rpc_method.h>
37 #include <grpcpp/security/credentials.h>
38 #include <grpcpp/support/channel_arguments.h>
39 #include <grpcpp/support/config.h>
40 #include <grpcpp/support/status.h>
41 #include "src/core/lib/gpr/string.h"
42 #include "src/core/lib/surface/completion_queue.h"
43
ChannelResetConnectionBackoff(Channel * channel)44 void ::grpc::experimental::ChannelResetConnectionBackoff(Channel* channel) {
45 grpc_impl::experimental::ChannelResetConnectionBackoff(channel);
46 }
47
48 namespace grpc_impl {
49
50 static ::grpc::internal::GrpcLibraryInitializer g_gli_initializer;
Channel(const grpc::string & host,grpc_channel * channel,std::vector<std::unique_ptr<::grpc::experimental::ClientInterceptorFactoryInterface>> interceptor_creators)51 Channel::Channel(const grpc::string& host, grpc_channel* channel,
52 std::vector<std::unique_ptr<
53 ::grpc::experimental::ClientInterceptorFactoryInterface>>
54 interceptor_creators)
55 : host_(host), c_channel_(channel) {
56 interceptor_creators_ = std::move(interceptor_creators);
57 g_gli_initializer.summon();
58 }
59
~Channel()60 Channel::~Channel() {
61 grpc_channel_destroy(c_channel_);
62 if (callback_cq_ != nullptr) {
63 callback_cq_->Shutdown();
64 }
65 }
66
67 namespace {
68
SliceFromArray(const char * arr,size_t len)69 inline grpc_slice SliceFromArray(const char* arr, size_t len) {
70 return ::grpc::g_core_codegen_interface->grpc_slice_from_copied_buffer(arr,
71 len);
72 }
73
GetChannelInfoField(grpc_channel * channel,grpc_channel_info * channel_info,char *** channel_info_field)74 grpc::string GetChannelInfoField(grpc_channel* channel,
75 grpc_channel_info* channel_info,
76 char*** channel_info_field) {
77 char* value = nullptr;
78 memset(channel_info, 0, sizeof(*channel_info));
79 *channel_info_field = &value;
80 grpc_channel_get_info(channel, channel_info);
81 if (value == nullptr) return "";
82 grpc::string result = value;
83 gpr_free(value);
84 return result;
85 }
86
87 } // namespace
88
GetLoadBalancingPolicyName() const89 grpc::string Channel::GetLoadBalancingPolicyName() const {
90 grpc_channel_info channel_info;
91 return GetChannelInfoField(c_channel_, &channel_info,
92 &channel_info.lb_policy_name);
93 }
94
GetServiceConfigJSON() const95 grpc::string Channel::GetServiceConfigJSON() const {
96 grpc_channel_info channel_info;
97 return GetChannelInfoField(c_channel_, &channel_info,
98 &channel_info.service_config_json);
99 }
100
101 namespace experimental {
102
ChannelResetConnectionBackoff(Channel * channel)103 void ChannelResetConnectionBackoff(Channel* channel) {
104 grpc_channel_reset_connect_backoff(channel->c_channel_);
105 }
106
107 } // namespace experimental
108
CreateCallInternal(const::grpc::internal::RpcMethod & method,::grpc::ClientContext * context,::grpc::CompletionQueue * cq,size_t interceptor_pos)109 ::grpc::internal::Call Channel::CreateCallInternal(
110 const ::grpc::internal::RpcMethod& method, ::grpc::ClientContext* context,
111 ::grpc::CompletionQueue* cq, size_t interceptor_pos) {
112 const bool kRegistered = method.channel_tag() && context->authority().empty();
113 grpc_call* c_call = nullptr;
114 if (kRegistered) {
115 c_call = grpc_channel_create_registered_call(
116 c_channel_, context->propagate_from_call_,
117 context->propagation_options_.c_bitmask(), cq->cq(),
118 method.channel_tag(), context->raw_deadline(), nullptr);
119 } else {
120 const ::grpc::string* host_str = nullptr;
121 if (!context->authority_.empty()) {
122 host_str = &context->authority_;
123 } else if (!host_.empty()) {
124 host_str = &host_;
125 }
126 grpc_slice method_slice =
127 SliceFromArray(method.name(), strlen(method.name()));
128 grpc_slice host_slice;
129 if (host_str != nullptr) {
130 host_slice = ::grpc::SliceFromCopiedString(*host_str);
131 }
132 c_call = grpc_channel_create_call(
133 c_channel_, context->propagate_from_call_,
134 context->propagation_options_.c_bitmask(), cq->cq(), method_slice,
135 host_str == nullptr ? nullptr : &host_slice, context->raw_deadline(),
136 nullptr);
137 grpc_slice_unref(method_slice);
138 if (host_str != nullptr) {
139 grpc_slice_unref(host_slice);
140 }
141 }
142 grpc_census_call_set_context(c_call, context->census_context());
143
144 // ClientRpcInfo should be set before call because set_call also checks
145 // whether the call has been cancelled, and if the call was cancelled, we
146 // should notify the interceptors too.
147 auto* info =
148 context->set_client_rpc_info(method.name(), method.method_type(), this,
149 interceptor_creators_, interceptor_pos);
150 context->set_call(c_call, shared_from_this());
151
152 return ::grpc::internal::Call(c_call, this, cq, info);
153 }
154
CreateCall(const::grpc::internal::RpcMethod & method,::grpc::ClientContext * context,CompletionQueue * cq)155 ::grpc::internal::Call Channel::CreateCall(
156 const ::grpc::internal::RpcMethod& method, ::grpc::ClientContext* context,
157 CompletionQueue* cq) {
158 return CreateCallInternal(method, context, cq, 0);
159 }
160
PerformOpsOnCall(::grpc::internal::CallOpSetInterface * ops,::grpc::internal::Call * call)161 void Channel::PerformOpsOnCall(::grpc::internal::CallOpSetInterface* ops,
162 ::grpc::internal::Call* call) {
163 ops->FillOps(
164 call); // Make a copy of call. It's fine since Call just has pointers
165 }
166
RegisterMethod(const char * method)167 void* Channel::RegisterMethod(const char* method) {
168 return grpc_channel_register_call(
169 c_channel_, method, host_.empty() ? nullptr : host_.c_str(), nullptr);
170 }
171
GetState(bool try_to_connect)172 grpc_connectivity_state Channel::GetState(bool try_to_connect) {
173 return grpc_channel_check_connectivity_state(c_channel_, try_to_connect);
174 }
175
176 namespace {
177
178 class TagSaver final : public ::grpc::internal::CompletionQueueTag {
179 public:
TagSaver(void * tag)180 explicit TagSaver(void* tag) : tag_(tag) {}
~TagSaver()181 ~TagSaver() override {}
FinalizeResult(void ** tag,bool *)182 bool FinalizeResult(void** tag, bool* /*status*/) override {
183 *tag = tag_;
184 delete this;
185 return true;
186 }
187
188 private:
189 void* tag_;
190 };
191
192 } // namespace
193
NotifyOnStateChangeImpl(grpc_connectivity_state last_observed,gpr_timespec deadline,::grpc::CompletionQueue * cq,void * tag)194 void Channel::NotifyOnStateChangeImpl(grpc_connectivity_state last_observed,
195 gpr_timespec deadline,
196 ::grpc::CompletionQueue* cq, void* tag) {
197 TagSaver* tag_saver = new TagSaver(tag);
198 grpc_channel_watch_connectivity_state(c_channel_, last_observed, deadline,
199 cq->cq(), tag_saver);
200 }
201
WaitForStateChangeImpl(grpc_connectivity_state last_observed,gpr_timespec deadline)202 bool Channel::WaitForStateChangeImpl(grpc_connectivity_state last_observed,
203 gpr_timespec deadline) {
204 ::grpc::CompletionQueue cq;
205 bool ok = false;
206 void* tag = nullptr;
207 NotifyOnStateChangeImpl(last_observed, deadline, &cq, nullptr);
208 cq.Next(&tag, &ok);
209 GPR_ASSERT(tag == nullptr);
210 return ok;
211 }
212
213 namespace {
214 class ShutdownCallback : public grpc_experimental_completion_queue_functor {
215 public:
ShutdownCallback()216 ShutdownCallback() {
217 functor_run = &ShutdownCallback::Run;
218 // Set inlineable to true since this callback is trivial and thus does not
219 // need to be run from the executor (triggering a thread hop). This should
220 // only be used by internal callbacks like this and not by user application
221 // code.
222 inlineable = true;
223 }
224 // TakeCQ takes ownership of the cq into the shutdown callback
225 // so that the shutdown callback will be responsible for destroying it
TakeCQ(::grpc::CompletionQueue * cq)226 void TakeCQ(::grpc::CompletionQueue* cq) { cq_ = cq; }
227
228 // The Run function will get invoked by the completion queue library
229 // when the shutdown is actually complete
Run(grpc_experimental_completion_queue_functor * cb,int)230 static void Run(grpc_experimental_completion_queue_functor* cb, int) {
231 auto* callback = static_cast<ShutdownCallback*>(cb);
232 delete callback->cq_;
233 delete callback;
234 }
235
236 private:
237 ::grpc::CompletionQueue* cq_ = nullptr;
238 };
239 } // namespace
240
CallbackCQ()241 ::grpc::CompletionQueue* Channel::CallbackCQ() {
242 // TODO(vjpai): Consider using a single global CQ for the default CQ
243 // if there is no explicit per-channel CQ registered
244 grpc::internal::MutexLock l(&mu_);
245 if (callback_cq_ == nullptr) {
246 auto* shutdown_callback = new ShutdownCallback;
247 callback_cq_ = new ::grpc::CompletionQueue(grpc_completion_queue_attributes{
248 GRPC_CQ_CURRENT_VERSION, GRPC_CQ_CALLBACK, GRPC_CQ_DEFAULT_POLLING,
249 shutdown_callback});
250
251 // Transfer ownership of the new cq to its own shutdown callback
252 shutdown_callback->TakeCQ(callback_cq_);
253 }
254 return callback_cq_;
255 }
256
257 } // namespace grpc_impl
258