1 /* 2 * Copyright 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #pragma once 18 19 #include <functional> 20 #include <memory> 21 #include <mutex> 22 23 #include "os/thread.h" 24 #include "os/utils.h" 25 26 namespace bluetooth { 27 namespace os { 28 29 // A single-shot alarm for reactor-based thread, implemented by Linux timerfd. 30 // When it's constructed, it will register a reactable on the specified thread; when it's destroyed, it will unregister 31 // itself from the thread. 32 class Alarm { 33 public: 34 // Create and register a single-shot alarm on given thread 35 explicit Alarm(Thread* thread); 36 37 // Unregister this alarm from the thread and release resource 38 ~Alarm(); 39 40 DISALLOW_COPY_AND_ASSIGN(Alarm); 41 42 // Schedule the alarm with given delay 43 void Schedule(Closure task, std::chrono::milliseconds delay); 44 45 // Cancel the alarm. No-op if it's not armed. 46 void Cancel(); 47 48 private: 49 Closure task_; 50 Thread* thread_; 51 int fd_ = 0; 52 Reactor::Reactable* token_; 53 mutable std::mutex mutex_; 54 void on_fire(); 55 }; 56 57 } // namespace os 58 59 } // namespace bluetooth 60