1 // 2 // 3 // Copyright 2016 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 GRPC_SRC_CORE_LIB_SURFACE_LAME_CLIENT_H 20 #define GRPC_SRC_CORE_LIB_SURFACE_LAME_CLIENT_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include <memory> 25 26 #include "absl/base/thread_annotations.h" 27 #include "absl/status/status.h" 28 #include "absl/status/statusor.h" 29 30 #include <grpc/grpc.h> 31 32 #include "src/core/lib/channel/channel_args.h" 33 #include "src/core/lib/channel/channel_fwd.h" 34 #include "src/core/lib/channel/promise_based_filter.h" 35 #include "src/core/lib/gprpp/sync.h" 36 #include "src/core/lib/iomgr/error.h" 37 #include "src/core/lib/promise/arena_promise.h" 38 #include "src/core/lib/transport/connectivity_state.h" 39 #include "src/core/lib/transport/transport.h" 40 41 #define GRPC_ARG_LAME_FILTER_ERROR "grpc.lame_filter_error" 42 43 namespace grpc_core { 44 45 // This filter becomes the entire channel stack for a channel that fails to be 46 // created. Every call returns failure. 47 class LameClientFilter : public ChannelFilter { 48 public: 49 static const grpc_channel_filter kFilter; 50 51 static absl::StatusOr<LameClientFilter> Create( 52 const ChannelArgs& args, ChannelFilter::Args filter_args); 53 ArenaPromise<ServerMetadataHandle> MakeCallPromise( 54 CallArgs call_args, NextPromiseFactory next_promise_factory) override; 55 bool StartTransportOp(grpc_transport_op*) override; 56 bool GetChannelInfo(const grpc_channel_info*) override; 57 58 private: 59 explicit LameClientFilter(absl::Status error); 60 61 absl::Status error_; 62 struct State { 63 State(); 64 Mutex mu; 65 ConnectivityStateTracker state_tracker ABSL_GUARDED_BY(mu); 66 }; 67 std::unique_ptr<State> state_; 68 }; 69 70 extern const grpc_arg_pointer_vtable kLameFilterErrorArgVtable; 71 72 grpc_arg MakeLameClientErrorArg(grpc_error_handle* error); 73 74 } // namespace grpc_core 75 76 #endif // GRPC_SRC_CORE_LIB_SURFACE_LAME_CLIENT_H 77