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 GRPCPP_ALARM_H
#define GRPCPP_ALARM_H
 
#include <functional>
 
#include <grpc/event_engine/event_engine.h>
#include <grpc/grpc.h>
#include <grpcpp/completion_queue.h>
#include <grpcpp/impl/completion_queue_tag.h>
#include <grpcpp/impl/grpc_library.h>
#include <grpcpp/support/time.h>
 
namespace grpc {
 
class Alarm : private grpc::internal::GrpcLibrary {
 public:
  Alarm();
 
  ~Alarm() override;
 
  template <typename T>
  Alarm(grpc::CompletionQueue* cq, const T& deadline, void* tag) : Alarm() {
    SetInternal(cq, grpc::TimePoint<T>(deadline).raw_time(), tag);
  }
 
  //
  // USAGE NOTE: This is frequently used to inject arbitrary tags into \a cq by
  // setting an immediate deadline. Such usage allows synchronizing an external
  // event with an application's \a grpc::CompletionQueue::Next loop.
  template <typename T>
  void Set(grpc::CompletionQueue* cq, const T& deadline, void* tag) {
    SetInternal(cq, grpc::TimePoint<T>(deadline).raw_time(), tag);
  }
 
  Alarm(const Alarm&) = delete;
  Alarm& operator=(const Alarm&) = delete;
 
  Alarm(Alarm&& rhs) noexcept : alarm_(rhs.alarm_) { rhs.alarm_ = nullptr; }
  Alarm& operator=(Alarm&& rhs) noexcept {
    std::swap(alarm_, rhs.alarm_);
    return *this;
  }
 
  void Cancel();
 
  template <typename T>
  void Set(const T& deadline, std::function<void(bool)> f) {
    SetInternal(grpc::TimePoint<T>(deadline).raw_time(), std::move(f));
  }
 
 private:
  void SetInternal(grpc::CompletionQueue* cq, gpr_timespec deadline, void* tag);
  void SetInternal(gpr_timespec deadline, std::function<void(bool)> f);
 
  grpc::internal::CompletionQueueTag* alarm_;
};
 
}  // namespace grpc
 
#endif  // GRPCPP_ALARM_H