| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #include <grpc++/channel.h> |
| |
| #include <memory> |
| |
| #include <grpc++/client_context.h> |
| #include <grpc++/completion_queue.h> |
| #include <grpc++/impl/call.h> |
| #include <grpc++/impl/codegen/completion_queue_tag.h> |
| #include <grpc++/impl/grpc_library.h> |
| #include <grpc++/impl/rpc_method.h> |
| #include <grpc++/security/credentials.h> |
| #include <grpc++/support/channel_arguments.h> |
| #include <grpc++/support/config.h> |
| #include <grpc++/support/status.h> |
| #include <grpc++/support/time.h> |
| #include <grpc/grpc.h> |
| #include <grpc/slice.h> |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/sync.h> |
| #include <grpc/support/thd.h> |
| #include <grpc/support/time.h> |
| #include "src/core/lib/profiling/timers.h" |
| |
| namespace grpc { |
| |
| namespace { |
| int kConnectivityCheckIntervalMsec = 500; |
| void WatchStateChange(void* arg); |
| |
| class TagSaver final : public CompletionQueueTag { |
| public: |
| explicit TagSaver(void* tag) : tag_(tag) {} |
| ~TagSaver() override {} |
| bool FinalizeResult(void** tag, bool* status) override { |
| *tag = tag_; |
| delete this; |
| return true; |
| } |
| |
| private: |
| void* tag_; |
| }; |
| |
| } // namespace |
| |
| // Constantly watches channel connectivity status to reconnect a transiently |
| // disconnected channel. This is a temporary work-around before we have retry |
| // support. |
| class ChannelConnectivityWatcher { |
| public: |
| ChannelConnectivityWatcher() { |
| gpr_thd_options options = gpr_thd_options_default(); |
| gpr_thd_options_set_joinable(&options); |
| gpr_thd_new(&thd_id_, &WatchStateChange, this, &options); |
| } |
| |
| ~ChannelConnectivityWatcher() { |
| cq_.Shutdown(); |
| if (thd_id_ != 0) { |
| gpr_thd_join(thd_id_); |
| } |
| } |
| |
| void WatchStateChangeImpl() { |
| bool ok = false; |
| void* tag = NULL; |
| CompletionQueue::NextStatus status = CompletionQueue::GOT_EVENT; |
| while (status != CompletionQueue::SHUTDOWN) { |
| status = cq_.AsyncNext(&tag, &ok, gpr_inf_past(GPR_CLOCK_REALTIME)); |
| // Make sure we've seen 2 TIMEOUTs before going to sleep |
| if (status == CompletionQueue::TIMEOUT) { |
| status = cq_.AsyncNext(&tag, &ok, gpr_inf_past(GPR_CLOCK_REALTIME)); |
| } |
| if (status == CompletionQueue::TIMEOUT) { |
| gpr_sleep_until( |
| gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), |
| gpr_time_from_millis(kConnectivityCheckIntervalMsec, |
| GPR_TIMESPAN))); |
| } else if (status == CompletionQueue::GOT_EVENT) { |
| ChannelState* channel_state = static_cast<ChannelState*>(tag); |
| channel_state->state = grpc_channel_check_connectivity_state( |
| channel_state->channel, false); |
| if (channel_state->state == GRPC_CHANNEL_SHUTDOWN) { |
| void* shutdown_tag = NULL; |
| channel_state->shutdown_cq.Next(&shutdown_tag, &ok); |
| delete channel_state; |
| } else { |
| TagSaver* tag_saver = new TagSaver(channel_state); |
| grpc_channel_watch_connectivity_state( |
| channel_state->channel, channel_state->state, |
| gpr_inf_future(GPR_CLOCK_REALTIME), cq_.cq(), tag_saver); |
| } |
| } |
| } |
| } |
| |
| void StartWatching(grpc_channel* channel) { |
| const char* disabled_str = |
| std::getenv("GRPC_DISABLE_CHANNEL_CONNECTIVITY_WATCHER"); |
| if (disabled_str == nullptr || strcmp(disabled_str, "1")) { |
| ChannelState* channel_state = new ChannelState(channel); |
| // The first grpc_channel_watch_connectivity_state() is not used to |
| // monitor the channel state change, but to hold a reference of the |
| // c channel. So that WatchStateChangeImpl() can observe state == |
| // GRPC_CHANNEL_SHUTDOWN without holding any lock on the channel object. |
| grpc_channel_watch_connectivity_state( |
| channel_state->channel, channel_state->state, |
| gpr_inf_future(GPR_CLOCK_REALTIME), channel_state->shutdown_cq.cq(), |
| new TagSaver(nullptr)); |
| grpc_channel_watch_connectivity_state( |
| channel_state->channel, channel_state->state, |
| gpr_inf_future(GPR_CLOCK_REALTIME), cq_.cq(), |
| new TagSaver(channel_state)); |
| } |
| } |
| |
| private: |
| struct ChannelState { |
| explicit ChannelState(grpc_channel* channel) |
| : channel(channel), state(GRPC_CHANNEL_IDLE){}; |
| grpc_channel* channel; |
| grpc_connectivity_state state; |
| CompletionQueue shutdown_cq; |
| }; |
| gpr_thd_id thd_id_; |
| CompletionQueue cq_; |
| CompletionQueue shutdown_cq_; |
| }; |
| |
| namespace { |
| void WatchStateChange(void* arg) { |
| ChannelConnectivityWatcher* watcher = |
| static_cast<ChannelConnectivityWatcher*>(arg); |
| watcher->WatchStateChangeImpl(); |
| } |
| |
| ChannelConnectivityWatcher channel_connectivity_watcher; |
| } // namespace |
| |
| static internal::GrpcLibraryInitializer g_gli_initializer; |
| Channel::Channel(const grpc::string& host, grpc_channel* channel) |
| : host_(host), c_channel_(channel) { |
| g_gli_initializer.summon(); |
| if (grpc_channel_support_connectivity_watcher(channel)) { |
| channel_connectivity_watcher.StartWatching(channel); |
| } |
| } |
| |
| Channel::~Channel() { |
| grpc_channel_destroy(c_channel_); |
| } |
| |
| namespace { |
| |
| grpc::string GetChannelInfoField(grpc_channel* channel, |
| grpc_channel_info* channel_info, |
| char*** channel_info_field) { |
| char* value = NULL; |
| memset(channel_info, 0, sizeof(*channel_info)); |
| *channel_info_field = &value; |
| grpc_channel_get_info(channel, channel_info); |
| if (value == NULL) return ""; |
| grpc::string result = value; |
| gpr_free(value); |
| return result; |
| } |
| |
| } // namespace |
| |
| grpc::string Channel::GetLoadBalancingPolicyName() const { |
| grpc_channel_info channel_info; |
| return GetChannelInfoField(c_channel_, &channel_info, |
| &channel_info.lb_policy_name); |
| } |
| |
| grpc::string Channel::GetServiceConfigJSON() const { |
| grpc_channel_info channel_info; |
| return GetChannelInfoField(c_channel_, &channel_info, |
| &channel_info.service_config_json); |
| } |
| |
| Call Channel::CreateCall(const RpcMethod& method, ClientContext* context, |
| CompletionQueue* cq) { |
| const bool kRegistered = method.channel_tag() && context->authority().empty(); |
| grpc_call* c_call = NULL; |
| if (kRegistered) { |
| c_call = grpc_channel_create_registered_call( |
| c_channel_, context->propagate_from_call_, |
| context->propagation_options_.c_bitmask(), cq->cq(), |
| method.channel_tag(), context->raw_deadline(), nullptr); |
| } else { |
| const char* host_str = NULL; |
| if (!context->authority().empty()) { |
| host_str = context->authority_.c_str(); |
| } else if (!host_.empty()) { |
| host_str = host_.c_str(); |
| } |
| grpc_slice method_slice = SliceFromCopiedString(method.name()); |
| grpc_slice host_slice; |
| if (host_str != nullptr) { |
| host_slice = SliceFromCopiedString(host_str); |
| } |
| c_call = grpc_channel_create_call( |
| c_channel_, context->propagate_from_call_, |
| context->propagation_options_.c_bitmask(), cq->cq(), method_slice, |
| host_str == nullptr ? nullptr : &host_slice, context->raw_deadline(), |
| nullptr); |
| grpc_slice_unref(method_slice); |
| if (host_str != nullptr) { |
| grpc_slice_unref(host_slice); |
| } |
| } |
| grpc_census_call_set_context(c_call, context->census_context()); |
| context->set_call(c_call, shared_from_this()); |
| return Call(c_call, this, cq); |
| } |
| |
| void Channel::PerformOpsOnCall(CallOpSetInterface* ops, Call* call) { |
| static const size_t MAX_OPS = 8; |
| size_t nops = 0; |
| grpc_op cops[MAX_OPS]; |
| ops->FillOps(call->call(), cops, &nops); |
| GPR_ASSERT(GRPC_CALL_OK == |
| grpc_call_start_batch(call->call(), cops, nops, ops, nullptr)); |
| } |
| |
| void* Channel::RegisterMethod(const char* method) { |
| return grpc_channel_register_call( |
| c_channel_, method, host_.empty() ? NULL : host_.c_str(), nullptr); |
| } |
| |
| grpc_connectivity_state Channel::GetState(bool try_to_connect) { |
| return grpc_channel_check_connectivity_state(c_channel_, try_to_connect); |
| } |
| |
| void Channel::NotifyOnStateChangeImpl(grpc_connectivity_state last_observed, |
| gpr_timespec deadline, |
| CompletionQueue* cq, void* tag) { |
| TagSaver* tag_saver = new TagSaver(tag); |
| grpc_channel_watch_connectivity_state(c_channel_, last_observed, deadline, |
| cq->cq(), tag_saver); |
| } |
| |
| bool Channel::WaitForStateChangeImpl(grpc_connectivity_state last_observed, |
| gpr_timespec deadline) { |
| CompletionQueue cq; |
| bool ok = false; |
| void* tag = NULL; |
| NotifyOnStateChangeImpl(last_observed, deadline, &cq, NULL); |
| cq.Next(&tag, &ok); |
| GPR_ASSERT(tag == NULL); |
| return ok; |
| } |
| |
| } // namespace grpc |