1 // 2 // 3 // Copyright 2017 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_CLIENT_CHANNEL_RETRY_THROTTLE_H 20 #define GRPC_SRC_CORE_CLIENT_CHANNEL_RETRY_THROTTLE_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include <stdint.h> 25 26 #include <map> 27 #include <string> 28 29 #include "absl/base/thread_annotations.h" 30 31 #include <grpc/support/atm.h> 32 33 #include "src/core/lib/gprpp/ref_counted.h" 34 #include "src/core/lib/gprpp/ref_counted_ptr.h" 35 #include "src/core/lib/gprpp/sync.h" 36 37 namespace grpc_core { 38 namespace internal { 39 40 /// Tracks retry throttling data for an individual server name. 41 class ServerRetryThrottleData final 42 : public RefCounted<ServerRetryThrottleData> { 43 public: 44 ServerRetryThrottleData(uintptr_t max_milli_tokens, 45 uintptr_t milli_token_ratio, 46 ServerRetryThrottleData* old_throttle_data); 47 ~ServerRetryThrottleData() override; 48 49 /// Records a failure. Returns true if it's okay to send a retry. 50 bool RecordFailure(); 51 52 /// Records a success. 53 void RecordSuccess(); 54 max_milli_tokens()55 uintptr_t max_milli_tokens() const { return max_milli_tokens_; } milli_token_ratio()56 uintptr_t milli_token_ratio() const { return milli_token_ratio_; } 57 58 private: 59 void GetReplacementThrottleDataIfNeeded( 60 ServerRetryThrottleData** throttle_data); 61 62 const uintptr_t max_milli_tokens_; 63 const uintptr_t milli_token_ratio_; 64 gpr_atm milli_tokens_; 65 // A pointer to the replacement for this ServerRetryThrottleData entry. 66 // If non-nullptr, then this entry is stale and must not be used. 67 // We hold a reference to the replacement. 68 gpr_atm replacement_ = 0; 69 }; 70 71 /// Global map of server name to retry throttle data. 72 class ServerRetryThrottleMap final { 73 public: 74 static ServerRetryThrottleMap* Get(); 75 76 /// Returns the failure data for \a server_name, creating a new entry if 77 /// needed. 78 RefCountedPtr<ServerRetryThrottleData> GetDataForServer( 79 const std::string& server_name, uintptr_t max_milli_tokens, 80 uintptr_t milli_token_ratio); 81 82 private: 83 using StringToDataMap = 84 std::map<std::string, RefCountedPtr<ServerRetryThrottleData>>; 85 86 Mutex mu_; 87 StringToDataMap map_ ABSL_GUARDED_BY(mu_); 88 }; 89 90 } // namespace internal 91 } // namespace grpc_core 92 93 #endif // GRPC_SRC_CORE_CLIENT_CHANNEL_RETRY_THROTTLE_H 94