services/audioflinger/datapath/TrackMetrics.h - LeafOS-Project/android_frameworks_av - Gitiles

 /*
  * Copyright (C) 2020 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.
  */

 #pragma once

 #include <binder/IActivityManager.h>
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
 #include <media/MediaMetricsItem.h>

 #include <mutex>

 namespace android {

 /**
  * TrackMetrics handles the AudioFlinger track metrics.
  *
  * We aggregate metrics for a particular device for proper analysis.
  * This includes power, performance, and usage metrics.
  *
  * This class is thread-safe with a lock for safety.  There is no risk of deadlock
  * as this class only executes external one-way calls in Mediametrics and does not
  * call any other AudioFlinger class.
  *
  * Terminology:
  * An AudioInterval is a contiguous playback segment.
  * An AudioIntervalGroup is a group of continuous playback segments on the same device.
  *
  * We currently deliver metrics based on an AudioIntervalGroup.
  */
 class TrackMetrics final {


 public:
     TrackMetrics(std::string metricsId, bool isOut, int clientUid)
         : mMetricsId(std::move(metricsId))
         , mIsOut(isOut)
         , mUid(clientUid)
         {}  // we don't log a constructor item, we wait for more info in logConstructor().

     ~TrackMetrics() {
         logEndInterval();
         std::lock_guard l(mLock);
         deliverCumulativeMetrics(AMEDIAMETRICS_PROP_EVENT_VALUE_ENDAUDIOINTERVALGROUP);
         // we don't log a destructor item here.
     }

     // Called under the following circumstances
     // 1) when we are added to the Thread
     // 2) when we have a createPatch in the Thread.
     void logBeginInterval(const std::string& devices) {
         std::lock_guard l(mLock);
         if (mDevices != devices) {
             deliverCumulativeMetrics(AMEDIAMETRICS_PROP_EVENT_VALUE_ENDAUDIOINTERVALGROUP);
             mDevices = devices;
             resetIntervalGroupMetrics();
             deliverDeviceMetrics(
                     AMEDIAMETRICS_PROP_EVENT_VALUE_BEGINAUDIOINTERVALGROUP, devices.c_str());
         }
         ++mIntervalCount;
         const auto& mActivityManager = getActivityManager();
         if (mActivityManager) {
             if (mIsOut) {
                 mActivityManager->logFgsApiBegin(AUDIO_API,
                     mUid,
                     IPCThreadState::self() -> getCallingPid());
             } else {
                 mActivityManager->logFgsApiBegin(MICROPHONE_API,
                     mUid,
                     IPCThreadState::self() -> getCallingPid());
             }
         }
     }

     void logConstructor(pid_t creatorPid, uid_t creatorUid, int32_t internalTrackId,
             const std::string& traits = {},
             audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT) const {
         // Once this item is logged by the server, the client can add properties.
         // no lock required, all local or const variables.
         mediametrics::LogItem item(mMetricsId);
         item.setPid(creatorPid)
             .setUid(creatorUid)
             .set(AMEDIAMETRICS_PROP_ALLOWUID, (int32_t)creatorUid)
             .set(AMEDIAMETRICS_PROP_EVENT,
                     AMEDIAMETRICS_PROP_PREFIX_SERVER AMEDIAMETRICS_PROP_EVENT_VALUE_CTOR)
             .set(AMEDIAMETRICS_PROP_INTERNALTRACKID, internalTrackId)
             .set(AMEDIAMETRICS_PROP_TRAITS, traits);
         // log streamType from the service, since client doesn't know chosen streamType.
         if (streamType != AUDIO_STREAM_DEFAULT) {
             item.set(AMEDIAMETRICS_PROP_STREAMTYPE, toString(streamType).c_str());
         }
         item.record();
     }

     // Called when we are removed from the Thread.
     void logEndInterval() {
         std::lock_guard l(mLock);
         if (mLastVolumeChangeTimeNs != 0) {
             logVolume_l(mVolume); // flush out the last volume.
             mLastVolumeChangeTimeNs = 0;
         }
         const auto& mActivityManager = getActivityManager();
         if (mActivityManager) {
             if (mIsOut) {
                 mActivityManager->logFgsApiEnd(AUDIO_API,
                     mUid,
                     IPCThreadState::self() -> getCallingPid());
             } else {
                 mActivityManager->logFgsApiEnd(MICROPHONE_API,
                     mUid,
                     IPCThreadState::self() -> getCallingPid());
             }
         }
     }

     void logInvalidate() const {
         // no lock required, all local or const variables.
         mediametrics::LogItem(mMetricsId)
             .set(AMEDIAMETRICS_PROP_EVENT,
                  AMEDIAMETRICS_PROP_EVENT_VALUE_INVALIDATE)
             .record();
     }

     void logLatencyAndStartup(double latencyMs, double startupMs) {
         mediametrics::LogItem(mMetricsId)
             .set(AMEDIAMETRICS_PROP_LATENCYMS, latencyMs)
             .set(AMEDIAMETRICS_PROP_STARTUPMS, startupMs)
             .record();
         std::lock_guard l(mLock);
         mDeviceLatencyMs.add(latencyMs);
         mDeviceStartupMs.add(startupMs);
     }

     void updateMinMaxVolume_l(int64_t durationNs, double deviceVolume)
             REQUIRES(mLock) {
         if (deviceVolume > mMaxVolume) {
             mMaxVolume = deviceVolume;
             mMaxVolumeDurationNs = durationNs;
         } else if (deviceVolume == mMaxVolume) {
             mMaxVolumeDurationNs += durationNs;
         }
         if (deviceVolume < mMinVolume) {
             mMinVolume = deviceVolume;
             mMinVolumeDurationNs = durationNs;
         } else if (deviceVolume == mMinVolume) {
             mMinVolumeDurationNs += durationNs;
         }
     }

     // may be called multiple times during an interval
     void logVolume(float volume) {
         std::lock_guard l(mLock);
         logVolume_l(volume);
     }

     // Use absolute numbers returned by AudioTrackShared.
     void logUnderruns(size_t count, size_t frames) {
         std::lock_guard l(mLock);
         mUnderrunCount = count;
         mUnderrunFrames = frames;
         // Consider delivering a message here (also be aware of excessive spam).
     }

 private:

     // no lock required - all arguments and constants.
     void deliverDeviceMetrics(const char *eventName, const char *devices) const {
         mediametrics::LogItem(mMetricsId)
             .set(AMEDIAMETRICS_PROP_EVENT, eventName)
             .set(mIsOut ? AMEDIAMETRICS_PROP_OUTPUTDEVICES
                    : AMEDIAMETRICS_PROP_INPUTDEVICES, devices)
            .record();
     }

     void logVolume_l(float volume) REQUIRES(mLock) {
         const int64_t timeNs = systemTime();
         const int64_t durationNs = mLastVolumeChangeTimeNs == 0
                 ? 0 : timeNs - mLastVolumeChangeTimeNs;
         if (durationNs > 0) {
             // See West's algorithm for weighted averages
             // https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
             mDeviceVolume += (mVolume - mDeviceVolume) * durationNs
                       / (durationNs + mDeviceTimeNs);
             mDeviceTimeNs += durationNs;
             mCumulativeTimeNs += durationNs;
         }
         updateMinMaxVolume_l(durationNs, mVolume); // always update.
         mVolume = volume;
         mLastVolumeChangeTimeNs = timeNs;
     }

     void deliverCumulativeMetrics(const char *eventName) const REQUIRES(mLock) {
         if (mIntervalCount > 0) {
             mediametrics::LogItem item(mMetricsId);
             item.set(AMEDIAMETRICS_PROP_CUMULATIVETIMENS, mCumulativeTimeNs)
                 .set(AMEDIAMETRICS_PROP_DEVICETIMENS, mDeviceTimeNs)
                 .set(AMEDIAMETRICS_PROP_EVENT, eventName)
                 .set(AMEDIAMETRICS_PROP_INTERVALCOUNT, (int32_t)mIntervalCount);
             if (mIsOut) {
                 item.set(AMEDIAMETRICS_PROP_DEVICEVOLUME, mDeviceVolume)
                     .set(AMEDIAMETRICS_PROP_DEVICEMAXVOLUMEDURATIONNS, mMaxVolumeDurationNs)
                     .set(AMEDIAMETRICS_PROP_DEVICEMAXVOLUME, mMaxVolume)
                     .set(AMEDIAMETRICS_PROP_DEVICEMINVOLUMEDURATIONNS, mMinVolumeDurationNs)
                     .set(AMEDIAMETRICS_PROP_DEVICEMINVOLUME, mMinVolume);
             }
             if (mDeviceLatencyMs.getN() > 0) {
                 item.set(AMEDIAMETRICS_PROP_DEVICELATENCYMS, mDeviceLatencyMs.getMean())
                     .set(AMEDIAMETRICS_PROP_DEVICESTARTUPMS, mDeviceStartupMs.getMean());
             }
             if (mUnderrunCount > 0) {
                 item.set(AMEDIAMETRICS_PROP_UNDERRUN,
                         (int32_t)(mUnderrunCount - mUnderrunCountSinceIntervalGroup))
                     .set(AMEDIAMETRICS_PROP_UNDERRUNFRAMES,
                         (int64_t)(mUnderrunFrames - mUnderrunFramesSinceIntervalGroup));
             }
             item.record();
         }
     }

     void resetIntervalGroupMetrics() REQUIRES(mLock) {
         // mDevices is not reset by resetIntervalGroupMetrics.

         mIntervalCount = 0;
         // mCumulativeTimeNs is not reset by resetIntervalGroupMetrics.
         mDeviceTimeNs = 0;

         mVolume = 0.f;
         mDeviceVolume = 0.f;
         mLastVolumeChangeTimeNs = 0;  // last time volume logged, cleared on endInterval
         mMinVolume = AMEDIAMETRICS_INITIAL_MIN_VOLUME;
         mMaxVolume = AMEDIAMETRICS_INITIAL_MAX_VOLUME;
         mMinVolumeDurationNs = 0;
         mMaxVolumeDurationNs = 0;

         mDeviceLatencyMs.reset();
         mDeviceStartupMs.reset();

         mUnderrunCountSinceIntervalGroup = mUnderrunCount;
         mUnderrunFramesSinceIntervalGroup = mUnderrunFrames;
         // do not reset mUnderrunCount - it keeps continuously running for tracks.
     }

     // Meyer's singleton is thread-safe.
     static const sp<IActivityManager>& getActivityManager() {
         static const auto activityManager = []() -> sp<IActivityManager> {
             const sp<IServiceManager> sm(defaultServiceManager());
             if (sm != nullptr) {
                  return interface_cast<IActivityManager>(sm->checkService(String16("activity")));
             }
             return nullptr;
         }();
         return activityManager;
     }

     const std::string mMetricsId;
     const bool        mIsOut;  // if true, than a playback track, otherwise used for record.

     static constexpr int AUDIO_API = 5;
     static constexpr int MICROPHONE_API = 6;
     const int         mUid;

     mutable           std::mutex mLock;

     // Devices in the interval group.
     std::string       mDevices GUARDED_BY(mLock);

     // Number of intervals and playing time
     int32_t           mIntervalCount GUARDED_BY(mLock) = 0;
     int64_t           mCumulativeTimeNs GUARDED_BY(mLock) = 0; // total time.
     int64_t           mDeviceTimeNs GUARDED_BY(mLock) = 0;     // time on device.

     // Average volume
     double            mVolume GUARDED_BY(mLock) = 0.f;       // last set volume.
     double            mDeviceVolume GUARDED_BY(mLock) = 0.f; // running average volume.
     int64_t           mLastVolumeChangeTimeNs GUARDED_BY(mLock) = 0;

     // Min/Max volume
     double            mMinVolume GUARDED_BY(mLock) = AMEDIAMETRICS_INITIAL_MIN_VOLUME;
     double            mMaxVolume GUARDED_BY(mLock) = AMEDIAMETRICS_INITIAL_MAX_VOLUME;
     int64_t           mMinVolumeDurationNs GUARDED_BY(mLock) = 0;
     int64_t           mMaxVolumeDurationNs GUARDED_BY(mLock) = 0;

     // latency and startup for each interval.
     audio_utils::Statistics<double> mDeviceLatencyMs GUARDED_BY(mLock);
     audio_utils::Statistics<double> mDeviceStartupMs GUARDED_BY(mLock);

     // underrun count and frames
     int64_t           mUnderrunCount GUARDED_BY(mLock) = 0;
     int64_t           mUnderrunFrames GUARDED_BY(mLock) = 0;
     int64_t           mUnderrunCountSinceIntervalGroup GUARDED_BY(mLock) = 0;
     int64_t           mUnderrunFramesSinceIntervalGroup GUARDED_BY(mLock) = 0;
 };

 } // namespace android
	/*
	* Copyright (C) 2020 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.
	*/

	#pragma once

	#include <binder/IActivityManager.h>
	#include <binder/IPCThreadState.h>
	#include <binder/IServiceManager.h>
	#include <media/MediaMetricsItem.h>

	#include <mutex>

	namespace android {

	/**
	* TrackMetrics handles the AudioFlinger track metrics.
	*
	* We aggregate metrics for a particular device for proper analysis.
	* This includes power, performance, and usage metrics.
	*
	* This class is thread-safe with a lock for safety. There is no risk of deadlock
	* as this class only executes external one-way calls in Mediametrics and does not
	* call any other AudioFlinger class.
	*
	* Terminology:
	* An AudioInterval is a contiguous playback segment.
	* An AudioIntervalGroup is a group of continuous playback segments on the same device.
	*
	* We currently deliver metrics based on an AudioIntervalGroup.
	*/
	class TrackMetrics final {


	public:
	TrackMetrics(std::string metricsId, bool isOut, int clientUid)
	: mMetricsId(std::move(metricsId))
	, mIsOut(isOut)
	, mUid(clientUid)
	{} // we don't log a constructor item, we wait for more info in logConstructor().

	~TrackMetrics() {
	logEndInterval();
	std::lock_guard l(mLock);
	deliverCumulativeMetrics(AMEDIAMETRICS_PROP_EVENT_VALUE_ENDAUDIOINTERVALGROUP);
	// we don't log a destructor item here.
	}

	// Called under the following circumstances
	// 1) when we are added to the Thread
	// 2) when we have a createPatch in the Thread.
	void logBeginInterval(const std::string& devices) {
	std::lock_guard l(mLock);
	if (mDevices != devices) {
	deliverCumulativeMetrics(AMEDIAMETRICS_PROP_EVENT_VALUE_ENDAUDIOINTERVALGROUP);
	mDevices = devices;
	resetIntervalGroupMetrics();
	deliverDeviceMetrics(
	AMEDIAMETRICS_PROP_EVENT_VALUE_BEGINAUDIOINTERVALGROUP, devices.c_str());
	}
	++mIntervalCount;
	const auto& mActivityManager = getActivityManager();
	if (mActivityManager) {
	if (mIsOut) {
	mActivityManager->logFgsApiBegin(AUDIO_API,
	mUid,
	IPCThreadState::self() -> getCallingPid());
	} else {
	mActivityManager->logFgsApiBegin(MICROPHONE_API,
	mUid,
	IPCThreadState::self() -> getCallingPid());
	}
	}
	}

	void logConstructor(pid_t creatorPid, uid_t creatorUid, int32_t internalTrackId,
	const std::string& traits = {},
	audio_stream_type_t streamType = AUDIO_STREAM_DEFAULT) const {
	// Once this item is logged by the server, the client can add properties.
	// no lock required, all local or const variables.
	mediametrics::LogItem item(mMetricsId);
	item.setPid(creatorPid)
	.setUid(creatorUid)
	.set(AMEDIAMETRICS_PROP_ALLOWUID, (int32_t)creatorUid)
	.set(AMEDIAMETRICS_PROP_EVENT,
	AMEDIAMETRICS_PROP_PREFIX_SERVER AMEDIAMETRICS_PROP_EVENT_VALUE_CTOR)
	.set(AMEDIAMETRICS_PROP_INTERNALTRACKID, internalTrackId)
	.set(AMEDIAMETRICS_PROP_TRAITS, traits);
	// log streamType from the service, since client doesn't know chosen streamType.
	if (streamType != AUDIO_STREAM_DEFAULT) {
	item.set(AMEDIAMETRICS_PROP_STREAMTYPE, toString(streamType).c_str());
	}
	item.record();
	}

	// Called when we are removed from the Thread.
	void logEndInterval() {
	std::lock_guard l(mLock);
	if (mLastVolumeChangeTimeNs != 0) {
	logVolume_l(mVolume); // flush out the last volume.
	mLastVolumeChangeTimeNs = 0;
	}
	const auto& mActivityManager = getActivityManager();
	if (mActivityManager) {
	if (mIsOut) {
	mActivityManager->logFgsApiEnd(AUDIO_API,
	mUid,
	IPCThreadState::self() -> getCallingPid());
	} else {
	mActivityManager->logFgsApiEnd(MICROPHONE_API,
	mUid,
	IPCThreadState::self() -> getCallingPid());
	}
	}
	}

	void logInvalidate() const {
	// no lock required, all local or const variables.
	mediametrics::LogItem(mMetricsId)
	.set(AMEDIAMETRICS_PROP_EVENT,
	AMEDIAMETRICS_PROP_EVENT_VALUE_INVALIDATE)
	.record();
	}

	void logLatencyAndStartup(double latencyMs, double startupMs) {
	mediametrics::LogItem(mMetricsId)
	.set(AMEDIAMETRICS_PROP_LATENCYMS, latencyMs)
	.set(AMEDIAMETRICS_PROP_STARTUPMS, startupMs)
	.record();
	std::lock_guard l(mLock);
	mDeviceLatencyMs.add(latencyMs);
	mDeviceStartupMs.add(startupMs);
	}

	void updateMinMaxVolume_l(int64_t durationNs, double deviceVolume)
	REQUIRES(mLock) {
	if (deviceVolume > mMaxVolume) {
	mMaxVolume = deviceVolume;
	mMaxVolumeDurationNs = durationNs;
	} else if (deviceVolume == mMaxVolume) {
	mMaxVolumeDurationNs += durationNs;
	}
	if (deviceVolume < mMinVolume) {
	mMinVolume = deviceVolume;
	mMinVolumeDurationNs = durationNs;
	} else if (deviceVolume == mMinVolume) {
	mMinVolumeDurationNs += durationNs;
	}
	}

	// may be called multiple times during an interval
	void logVolume(float volume) {
	std::lock_guard l(mLock);
	logVolume_l(volume);
	}

	// Use absolute numbers returned by AudioTrackShared.
	void logUnderruns(size_t count, size_t frames) {
	std::lock_guard l(mLock);
	mUnderrunCount = count;
	mUnderrunFrames = frames;
	// Consider delivering a message here (also be aware of excessive spam).
	}

	private:

	// no lock required - all arguments and constants.
	void deliverDeviceMetrics(const char eventName, const char devices) const {
	mediametrics::LogItem(mMetricsId)
	.set(AMEDIAMETRICS_PROP_EVENT, eventName)
	.set(mIsOut ? AMEDIAMETRICS_PROP_OUTPUTDEVICES
	: AMEDIAMETRICS_PROP_INPUTDEVICES, devices)
	.record();
	}

	void logVolume_l(float volume) REQUIRES(mLock) {
	const int64_t timeNs = systemTime();
	const int64_t durationNs = mLastVolumeChangeTimeNs == 0
	? 0 : timeNs - mLastVolumeChangeTimeNs;
	if (durationNs > 0) {
	// See West's algorithm for weighted averages
	// https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
	mDeviceVolume += (mVolume - mDeviceVolume) * durationNs
	/ (durationNs + mDeviceTimeNs);
	mDeviceTimeNs += durationNs;
	mCumulativeTimeNs += durationNs;
	}
	updateMinMaxVolume_l(durationNs, mVolume); // always update.
	mVolume = volume;
	mLastVolumeChangeTimeNs = timeNs;
	}

	void deliverCumulativeMetrics(const char *eventName) const REQUIRES(mLock) {
	if (mIntervalCount > 0) {
	mediametrics::LogItem item(mMetricsId);
	item.set(AMEDIAMETRICS_PROP_CUMULATIVETIMENS, mCumulativeTimeNs)
	.set(AMEDIAMETRICS_PROP_DEVICETIMENS, mDeviceTimeNs)
	.set(AMEDIAMETRICS_PROP_EVENT, eventName)
	.set(AMEDIAMETRICS_PROP_INTERVALCOUNT, (int32_t)mIntervalCount);
	if (mIsOut) {
	item.set(AMEDIAMETRICS_PROP_DEVICEVOLUME, mDeviceVolume)
	.set(AMEDIAMETRICS_PROP_DEVICEMAXVOLUMEDURATIONNS, mMaxVolumeDurationNs)
	.set(AMEDIAMETRICS_PROP_DEVICEMAXVOLUME, mMaxVolume)
	.set(AMEDIAMETRICS_PROP_DEVICEMINVOLUMEDURATIONNS, mMinVolumeDurationNs)
	.set(AMEDIAMETRICS_PROP_DEVICEMINVOLUME, mMinVolume);
	}
	if (mDeviceLatencyMs.getN() > 0) {
	item.set(AMEDIAMETRICS_PROP_DEVICELATENCYMS, mDeviceLatencyMs.getMean())
	.set(AMEDIAMETRICS_PROP_DEVICESTARTUPMS, mDeviceStartupMs.getMean());
	}
	if (mUnderrunCount > 0) {
	item.set(AMEDIAMETRICS_PROP_UNDERRUN,
	(int32_t)(mUnderrunCount - mUnderrunCountSinceIntervalGroup))
	.set(AMEDIAMETRICS_PROP_UNDERRUNFRAMES,
	(int64_t)(mUnderrunFrames - mUnderrunFramesSinceIntervalGroup));
	}
	item.record();
	}
	}

	void resetIntervalGroupMetrics() REQUIRES(mLock) {
	// mDevices is not reset by resetIntervalGroupMetrics.

	mIntervalCount = 0;
	// mCumulativeTimeNs is not reset by resetIntervalGroupMetrics.
	mDeviceTimeNs = 0;

	mVolume = 0.f;
	mDeviceVolume = 0.f;
	mLastVolumeChangeTimeNs = 0; // last time volume logged, cleared on endInterval
	mMinVolume = AMEDIAMETRICS_INITIAL_MIN_VOLUME;
	mMaxVolume = AMEDIAMETRICS_INITIAL_MAX_VOLUME;
	mMinVolumeDurationNs = 0;
	mMaxVolumeDurationNs = 0;

	mDeviceLatencyMs.reset();
	mDeviceStartupMs.reset();

	mUnderrunCountSinceIntervalGroup = mUnderrunCount;
	mUnderrunFramesSinceIntervalGroup = mUnderrunFrames;
	// do not reset mUnderrunCount - it keeps continuously running for tracks.
	}

	// Meyer's singleton is thread-safe.
	static const sp<IActivityManager>& getActivityManager() {
	static const auto activityManager = []() -> sp<IActivityManager> {
	const sp<IServiceManager> sm(defaultServiceManager());
	if (sm != nullptr) {
	return interface_cast<IActivityManager>(sm->checkService(String16("activity")));
	}
	return nullptr;
	}();
	return activityManager;
	}

	const std::string mMetricsId;
	const bool mIsOut; // if true, than a playback track, otherwise used for record.

	static constexpr int AUDIO_API = 5;
	static constexpr int MICROPHONE_API = 6;
	const int mUid;

	mutable std::mutex mLock;

	// Devices in the interval group.
	std::string mDevices GUARDED_BY(mLock);

	// Number of intervals and playing time
	int32_t mIntervalCount GUARDED_BY(mLock) = 0;
	int64_t mCumulativeTimeNs GUARDED_BY(mLock) = 0; // total time.
	int64_t mDeviceTimeNs GUARDED_BY(mLock) = 0; // time on device.

	// Average volume
	double mVolume GUARDED_BY(mLock) = 0.f; // last set volume.
	double mDeviceVolume GUARDED_BY(mLock) = 0.f; // running average volume.
	int64_t mLastVolumeChangeTimeNs GUARDED_BY(mLock) = 0;

	// Min/Max volume
	double mMinVolume GUARDED_BY(mLock) = AMEDIAMETRICS_INITIAL_MIN_VOLUME;
	double mMaxVolume GUARDED_BY(mLock) = AMEDIAMETRICS_INITIAL_MAX_VOLUME;
	int64_t mMinVolumeDurationNs GUARDED_BY(mLock) = 0;
	int64_t mMaxVolumeDurationNs GUARDED_BY(mLock) = 0;

	// latency and startup for each interval.
	audio_utils::Statistics<double> mDeviceLatencyMs GUARDED_BY(mLock);
	audio_utils::Statistics<double> mDeviceStartupMs GUARDED_BY(mLock);

	// underrun count and frames
	int64_t mUnderrunCount GUARDED_BY(mLock) = 0;
	int64_t mUnderrunFrames GUARDED_BY(mLock) = 0;
	int64_t mUnderrunCountSinceIntervalGroup GUARDED_BY(mLock) = 0;
	int64_t mUnderrunFramesSinceIntervalGroup GUARDED_BY(mLock) = 0;
	};

	} // namespace android