| /* |
| * 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 |