ceph/src/seastar/include/seastar/core/manual_clock.hh

   1 /*
   2  * This file is open source software, licensed to you under the terms
   3  * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   4  * distributed with this work for additional information regarding copyright
   5  * ownership.  You may not use this file except in compliance with the License.
   6  *
   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,
  12  * software distributed under the License is distributed on an
  13  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14  * KIND, either express or implied.  See the License for the
  15  * specific language governing permissions and limitations
  16  * under the License.
  17  */
  18 /*
  19  * Copyright (C) 2016 ScyllaDB
  20  */
  21
  22 #pragma once
  23
  24 #include <chrono>
  25
  26 namespace seastar {
  27
  28 class manual_clock {
  29 public:
  30     using rep = int64_t;
  31     using period = std::chrono::nanoseconds::period;
  32     using duration = std::chrono::duration<rep, period>;
  33     using time_point = std::chrono::time_point<manual_clock, duration>;
  34 private:
  35     static std::atomic<rep> _now;
  36     static void expire_timers();
  37 public:
  38     manual_clock();
  39     static time_point now() {
  40         return time_point(duration(_now.load(std::memory_order_relaxed)));
  41     }
  42     static void advance(duration d);
  43 };
  44
  45 }
  46