alarm.h

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/*
 *
 * 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.
 *
 */

#ifndef GRPCXX_ALARM_H
#define GRPCXX_ALARM_H

#include <grpc++/impl/codegen/completion_queue.h>
#include <grpc++/impl/codegen/completion_queue_tag.h>
#include <grpc++/impl/codegen/grpc_library.h>
#include <grpc++/impl/codegen/time.h>
#include <grpc++/impl/grpc_library.h>
#include <grpc/grpc.h>

struct grpc_alarm;

namespace grpc {

class CompletionQueue;

class Alarm : private GrpcLibraryCodegen {
 public:
  Alarm() : tag_(nullptr), alarm_(grpc_alarm_create(nullptr)) {}

  template <typename T>
  Alarm(CompletionQueue* cq, const T& deadline, void* tag)
      : tag_(tag), alarm_(grpc_alarm_create(nullptr)) {
    grpc_alarm_set(alarm_, cq->cq(), TimePoint<T>(deadline).raw_time(),
                   static_cast<void*>(&tag_), nullptr);
  }

  template <typename T>
  void Set(CompletionQueue* cq, const T& deadline, void* tag) {
    tag_.Set(tag);
    grpc_alarm_set(alarm_, cq->cq(), TimePoint<T>(deadline).raw_time(),
                   static_cast<void*>(&tag_), nullptr);
  }

  Alarm(const Alarm&) = delete;
  Alarm& operator=(const Alarm&) = delete;

  Alarm(Alarm&& rhs) : tag_(rhs.tag_), alarm_(rhs.alarm_) {
    rhs.alarm_ = nullptr;
  }
  Alarm& operator=(Alarm&& rhs) {
    tag_ = rhs.tag_;
    alarm_ = rhs.alarm_;
    rhs.alarm_ = nullptr;
    return *this;
  }

  ~Alarm() {
    if (alarm_ != nullptr) grpc_alarm_destroy(alarm_, nullptr);
  }

  void Cancel() {
    if (alarm_ != nullptr) grpc_alarm_cancel(alarm_, nullptr);
  }

 private:
  class AlarmEntry : public internal::CompletionQueueTag {
   public:
    AlarmEntry(void* tag) : tag_(tag) {}
    void Set(void* tag) { tag_ = tag; }
    bool FinalizeResult(void** tag, bool* status) override {
      *tag = tag_;
      return true;
    }

   private:
    void* tag_;
  };

  AlarmEntry tag_;
  grpc_alarm* alarm_;  // owned
};

}  // namespace grpc

#endif  // GRPCXX_ALARM_H