1 /* 2 * Copyright (C) 2023 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef WATCHDOG_H 17 #define WATCHDOG_H 18 19 #include <atomic> 20 #include <condition_variable> 21 #include "media_dfx.h" 22 #include "media_log.h" 23 24 namespace OHOS { 25 namespace Media { 26 /** 27 * More than timeoutMs_ If Notify() is not used to trigger the dog feeding action within, the Alarm() action 28 * will be triggered. When notify() is restored, the AlarmRecovery() action will be triggered. 29 * See interface details for specific usage. 30 */ 31 class __attribute__((visibility("default"))) WatchDog { 32 public: 33 WatchDog() = default; WatchDog(uint32_t timeoutMs)34 explicit WatchDog(uint32_t timeoutMs) : timeoutMs_(timeoutMs) {}; 35 ~WatchDog(); 36 37 /** 38 * Create a listening thread. Repeated calls do not take effect. 39 */ 40 void EnableWatchDog(); 41 42 /** 43 * End and destroy the listening thread. 44 */ 45 void DisableWatchDog(); 46 47 /** 48 * The listening thread enters the paused state (semaphore waiting). 49 */ 50 void PauseWatchDog(); 51 52 /** 53 * The listening thread resumes running and starts a new round of timeout waiting. 54 */ 55 void ResumeWatchDog(); 56 57 /** 58 * Watchdog feeding action. 59 * It needs to be called regularly within the timeoutMs_ time, otherwise Alarm() will be triggered. 60 * When the watchdog recovers, AlarmRecovery() will be triggered. 61 */ 62 void Notify(); 63 64 /** 65 * This event will be triggered when the watchdog times out. A timeout will only be triggered once. 66 * Please inherit and override the interface. 67 */ 68 virtual void Alarm(); 69 70 /** 71 * This event will be triggered when the watchdog is restored. 72 */ 73 virtual void AlarmRecovery(); 74 75 /** 76 * The thread used to monitor the watchdog. 77 * The watchdog timeout will trigger the Alarm() action and enter the pause state, 78 * until Notify() triggers the AlarmRecovery() again, and then continue to run. 79 */ 80 void WatchDogThread(); 81 82 private: 83 std::atomic<bool> disabling = false; 84 bool enable_ = false; 85 bool pause_ = false; 86 bool paused_ = false; 87 bool alarmed_ = false; 88 uint32_t timeoutMs_ = 1000; // Default 1000ms. 89 uint32_t count_ = 0; 90 std::condition_variable cond_; 91 std::mutex mutex_; 92 std::unique_ptr<std::thread> thread_; 93 }; 94 } // namespace Media 95 } // namespace OHOS 96 97 #endif 98