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 <array> 20 #include <functional> 21 #include <mutex> 22 #include <thread> 23 24 #include <android-base/thread_annotations.h> 25 26 #include <scheduler/TimeKeeper.h> 27 28 namespace android::scheduler { 29 30 class Timer : public TimeKeeper { 31 public: 32 Timer(); 33 ~Timer(); 34 35 nsecs_t now() const final; 36 37 // NB: alarmAt and alarmCancel are threadsafe; with the last-returning function being effectual 38 // Most users will want to serialize thes calls so as to be aware of the timer state. 39 void alarmAt(std::function<void()>, nsecs_t time) final; 40 void alarmCancel() final; 41 42 void dump(std::string&) const final; 43 44 protected: 45 // For unit testing 46 int mEpollFd = -1; 47 48 private: 49 enum class DebugState { 50 Reset, 51 Running, 52 Waiting, 53 Reading, 54 InCallback, 55 Terminated, 56 57 ftl_last = Terminated 58 }; 59 60 void reset() EXCLUDES(mMutex); 61 void cleanup() REQUIRES(mMutex); 62 void setDebugState(DebugState) EXCLUDES(mMutex); 63 64 int mTimerFd = -1; 65 66 std::array<int, 2> mPipes = {-1, -1}; 67 68 std::thread mDispatchThread; 69 void threadMain(); 70 bool dispatch(); 71 void endDispatch(); 72 73 mutable std::mutex mMutex; 74 std::function<void()> mCallback GUARDED_BY(mMutex); 75 bool mExpectingCallback GUARDED_BY(mMutex) = false; 76 DebugState mDebugState GUARDED_BY(mMutex); 77 }; 78 79 } // namespace android::scheduler 80