retry_throttle.h

Go to the documentation of this file.

/*
 *
 * Copyright 2017 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_RETRY_THROTTLE_H
#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H
 
#include <grpc/support/port_platform.h>
 
#include <stdint.h>
 
#include <map>
#include <string>
 
#include "absl/base/thread_annotations.h"
 
#include <grpc/support/atm.h>
 
#include "src/core/lib/gprpp/ref_counted.h"
#include "src/core/lib/gprpp/ref_counted_ptr.h"
#include "src/core/lib/gprpp/sync.h"
 
namespace grpc_core {
namespace internal {
 
class ServerRetryThrottleData : public RefCounted<ServerRetryThrottleData> {
 public:
  ServerRetryThrottleData(intptr_t max_milli_tokens, intptr_t milli_token_ratio,
                          ServerRetryThrottleData* old_throttle_data);
  ~ServerRetryThrottleData() override;
 
  bool RecordFailure();
 
  void RecordSuccess();
 
  intptr_t max_milli_tokens() const { return max_milli_tokens_; }
  intptr_t milli_token_ratio() const { return milli_token_ratio_; }
 
 private:
  void GetReplacementThrottleDataIfNeeded(
      ServerRetryThrottleData** throttle_data);
 
  const intptr_t max_milli_tokens_;
  const intptr_t milli_token_ratio_;
  gpr_atm milli_tokens_;
  // A pointer to the replacement for this ServerRetryThrottleData entry.
  // If non-nullptr, then this entry is stale and must not be used.
  // We hold a reference to the replacement.
  gpr_atm replacement_ = 0;
};
 
class ServerRetryThrottleMap {
 public:
  static ServerRetryThrottleMap* Get();
 
  RefCountedPtr<ServerRetryThrottleData> GetDataForServer(
      const std::string& server_name, intptr_t max_milli_tokens,
      intptr_t milli_token_ratio);
 
 private:
  using StringToDataMap =
      std::map<std::string, RefCountedPtr<ServerRetryThrottleData>>;
 
  Mutex mu_;
  StringToDataMap map_ ABSL_GUARDED_BY(mu_);
};
 
}  // namespace internal
}  // namespace grpc_core
 
#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */