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Diffstat (limited to 'src/core/ext/filters/client_channel/request_routing.h')
| -rw-r--r-- | src/core/ext/filters/client_channel/request_routing.h | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/core/ext/filters/client_channel/request_routing.h b/src/core/ext/filters/client_channel/request_routing.h new file mode 100644 index 0000000000..0c671229c8 --- /dev/null +++ b/src/core/ext/filters/client_channel/request_routing.h @@ -0,0 +1,177 @@ +/* + * + * Copyright 2018 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. + * + */ + +#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_REQUEST_ROUTING_H +#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_REQUEST_ROUTING_H + +#include <grpc/support/port_platform.h> + +#include "src/core/ext/filters/client_channel/client_channel_channelz.h" +#include "src/core/ext/filters/client_channel/client_channel_factory.h" +#include "src/core/ext/filters/client_channel/lb_policy.h" +#include "src/core/ext/filters/client_channel/resolver.h" +#include "src/core/lib/channel/channel_args.h" +#include "src/core/lib/channel/channel_stack.h" +#include "src/core/lib/debug/trace.h" +#include "src/core/lib/gprpp/inlined_vector.h" +#include "src/core/lib/gprpp/orphanable.h" +#include "src/core/lib/iomgr/call_combiner.h" +#include "src/core/lib/iomgr/closure.h" +#include "src/core/lib/iomgr/polling_entity.h" +#include "src/core/lib/iomgr/pollset_set.h" +#include "src/core/lib/transport/connectivity_state.h" +#include "src/core/lib/transport/metadata_batch.h" + +namespace grpc_core { + +class RequestRouter { + public: + class Request { + public: + // Synchronous callback that applies the service config to a call. + // Returns false if the call should be failed. + typedef bool (*ApplyServiceConfigCallback)(void* user_data); + + Request(grpc_call_stack* owning_call, grpc_call_combiner* call_combiner, + grpc_polling_entity* pollent, + grpc_metadata_batch* send_initial_metadata, + uint32_t* send_initial_metadata_flags, + ApplyServiceConfigCallback apply_service_config, + void* apply_service_config_user_data, grpc_closure* on_route_done); + + ~Request(); + + // TODO(roth): It seems a bit ugly to expose this member in a + // non-const way. Find a better API to avoid this. + LoadBalancingPolicy::PickState* pick() { return &pick_; } + + private: + friend class RequestRouter; + + class ResolverResultWaiter; + class AsyncPickCanceller; + + void ProcessServiceConfigAndStartLbPickLocked(); + void StartLbPickLocked(); + static void LbPickDoneLocked(void* arg, grpc_error* error); + + void MaybeAddCallToInterestedPartiesLocked(); + void MaybeRemoveCallFromInterestedPartiesLocked(); + + // Populated by caller. + grpc_call_stack* owning_call_; + grpc_call_combiner* call_combiner_; + grpc_polling_entity* pollent_; + ApplyServiceConfigCallback apply_service_config_; + void* apply_service_config_user_data_; + grpc_closure* on_route_done_; + LoadBalancingPolicy::PickState pick_; + + // Internal state. + RequestRouter* request_router_ = nullptr; + bool pollent_added_to_interested_parties_ = false; + grpc_closure on_pick_done_; + AsyncPickCanceller* pick_canceller_ = nullptr; + }; + + // Synchronous callback that takes the service config JSON string and + // LB policy name. + // Returns true if the service config has changed since the last result. + typedef bool (*ProcessResolverResultCallback)(void* user_data, + const grpc_channel_args& args, + const char** lb_policy_name, + grpc_json** lb_policy_config); + + RequestRouter(grpc_channel_stack* owning_stack, grpc_combiner* combiner, + grpc_client_channel_factory* client_channel_factory, + grpc_pollset_set* interested_parties, TraceFlag* tracer, + ProcessResolverResultCallback process_resolver_result, + void* process_resolver_result_user_data, const char* target_uri, + const grpc_channel_args* args, grpc_error** error); + + ~RequestRouter(); + + void set_channelz_node(channelz::ClientChannelNode* channelz_node) { + channelz_node_ = channelz_node; + } + + void RouteCallLocked(Request* request); + + // TODO(roth): Add methods to cancel picks. + + void ShutdownLocked(grpc_error* error); + + void ExitIdleLocked(); + void ResetConnectionBackoffLocked(); + + grpc_connectivity_state GetConnectivityState(); + void NotifyOnConnectivityStateChange(grpc_connectivity_state* state, + grpc_closure* closure); + + LoadBalancingPolicy* lb_policy() const { return lb_policy_.get(); } + + private: + using TraceStringVector = grpc_core::InlinedVector<char*, 3>; + + class ReresolutionRequestHandler; + class LbConnectivityWatcher; + + void StartResolvingLocked(); + void OnResolverShutdownLocked(grpc_error* error); + void CreateNewLbPolicyLocked(const char* lb_policy_name, grpc_json* lb_config, + grpc_connectivity_state* connectivity_state, + grpc_error** connectivity_error, + TraceStringVector* trace_strings); + void MaybeAddTraceMessagesForAddressChangesLocked( + TraceStringVector* trace_strings); + void ConcatenateAndAddChannelTraceLocked( + TraceStringVector* trace_strings) const; + static void OnResolverResultChangedLocked(void* arg, grpc_error* error); + + void SetConnectivityStateLocked(grpc_connectivity_state state, + grpc_error* error, const char* reason); + + // Passed in from caller at construction time. + grpc_channel_stack* owning_stack_; + grpc_combiner* combiner_; + grpc_client_channel_factory* client_channel_factory_; + grpc_pollset_set* interested_parties_; + TraceFlag* tracer_; + + channelz::ClientChannelNode* channelz_node_ = nullptr; + + // Resolver and associated state. + OrphanablePtr<Resolver> resolver_; + ProcessResolverResultCallback process_resolver_result_; + void* process_resolver_result_user_data_; + bool started_resolving_ = false; + grpc_channel_args* resolver_result_ = nullptr; + bool previous_resolution_contained_addresses_ = false; + grpc_closure_list waiting_for_resolver_result_closures_; + grpc_closure on_resolver_result_changed_; + + // LB policy and associated state. + OrphanablePtr<LoadBalancingPolicy> lb_policy_; + bool exit_idle_when_lb_policy_arrives_ = false; + + grpc_connectivity_state_tracker state_tracker_; +}; + +} // namespace grpc_core + +#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_REQUEST_ROUTING_H */ |