/* * Copyright (C) 2012 The Android Open Source Project * * 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. */ // The watchdog thread runs periodically. It has two functions: // (a) verify that adequate CPU time is available, and log // as soon as possible when there appears to be a CPU shortage // (b) monitor the other threads [not yet implemented] #ifndef AUDIO_WATCHDOG_H #define AUDIO_WATCHDOG_H #include <time.h> #include <utils/Thread.h> namespace android { // Keeps a cache of AudioWatchdog statistics that can be logged by dumpsys. // The usual caveats about atomicity of information apply. struct AudioWatchdogDump { AudioWatchdogDump() : mUnderruns(0), mLogs(0), mMostRecent(0) { } /*virtual*/ ~AudioWatchdogDump() { } uint32_t mUnderruns; // total number of underruns uint32_t mLogs; // total number of log messages time_t mMostRecent; // time of most recent log void dump(int fd); // should only be called on a stable copy, not the original }; class AudioWatchdog : public Thread { public: explicit AudioWatchdog(unsigned periodMs = 50) : Thread(false /*canCallJava*/), mPaused(false), mPeriodNs(periodMs * 1000000), mMaxCycleNs(mPeriodNs * 2), // mOldTs // mLogTs initialized below mOldTsValid(false), mUnderruns(0), mLogs(0), mDump(&mDummyDump) { #define MIN_TIME_BETWEEN_LOGS_SEC 60 // force an immediate log on first underrun mLogTs.tv_sec = MIN_TIME_BETWEEN_LOGS_SEC; mLogTs.tv_nsec = 0; } virtual ~AudioWatchdog() { } // Do not call Thread::requestExitAndWait() without first calling requestExit(). // Thread::requestExitAndWait() is not virtual, and the implementation doesn't do enough. virtual void requestExit(); // FIXME merge API and implementation with AudioTrackThread void pause(); // suspend thread from execution at next loop boundary void resume(); // allow thread to execute, if not requested to exit // Where to store the dump, or NULL to not update void setDump(AudioWatchdogDump* dump); private: virtual bool threadLoop(); Mutex mMyLock; // Thread::mLock is private Condition mMyCond; // Thread::mThreadExitedCondition is private bool mPaused; // whether thread is currently paused uint32_t mPeriodNs; // nominal period uint32_t mMaxCycleNs; // maximum allowed time of one cycle before declaring underrun struct timespec mOldTs; // monotonic time when threadLoop last ran struct timespec mLogTs; // time since last log bool mOldTsValid; // whether mOldTs is valid uint32_t mUnderruns; // total number of underruns uint32_t mLogs; // total number of logs AudioWatchdogDump* mDump; // where to store the dump, always non-NULL AudioWatchdogDump mDummyDump; // default area for dump in case setDump() is not called }; } // namespace android #endif // AUDIO_WATCHDOG_H