我们接着上篇 Android Sprd省电管理（二）应用省电模式设置流程，讲下锁屏清理的原理
锁屏清理简介：
锁屏清理目的是减少待机应用从而来减少待机功耗。锁屏清理是在待机一段时间后才开始进行。
该时间值大于 1min。出于功耗考虑没有采用可唤醒的 alarm 来设置该 1min 定时器。而是采
用非可唤醒的 alarm。而非可唤醒 alarm 需要有可唤醒 alarm 才会触发，因此这会导致开始
清理的时间远大于 1min。但一般 10 分钟内都会有可唤醒 alarm，也就是 10 分钟内会进行清理
一些应用不会被清理，即使在已经被设置为清理的情况下。这些应用包括：
a) 输入法应用；
b) 默认的系统服务应用，如壁纸服务应用，默认短信服务应用等；
c) 当前灭屏前可见的应用；
d)正在播放音乐的应用；
e) 正在下载的应用；
f) 内置系统应用；
上述这些类型的应用不能清理，清理后会导致使用上的体验问题。
锁屏清理流程：
在PowerContorller.java中注册了一些设备状态变化的广播
private void registerForBroadcasts() {
IntentFilter intentFilter = new IntentFilter();
//亮屏广播
intentFilter.addAction(Intent.ACTION_SCREEN_ON);
//灭屏广播
intentFilter.addAction(Intent.ACTION_SCREEN_OFF);
intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
intentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
intentFilter.addAction(PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED);
intentFilter.addAction(ACTION_CHECK_APPSTATE);
intentFilter.addAction(Intent.ACTION_BOOT_COMPLETED);
intentFilter.addAction(PowerManager.ACTION_POWER_SAVE_WHITELIST_CHANGED);
intentFilter.addAction(INTENT_SCHEDULEMODE_ALARM);
mContext.registerReceiver(
new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_CHECK_APPSTATE.equals(action)) {
msgHandler.removeMessages(MSG_CHECK);
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_CHECK));
// for PowerGuru Interval upadate
if (mPowerGuruAligningStart) {
msgHandler.removeMessages(MSG_UPDATE_POWERGURU_INTERVAL);
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_UPDATE_POWERGURU_INTERVAL));
}
} else if(Intent.ACTION_BOOT_COMPLETED.equals(action)) {
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_BOOT_COMPLETED));
} else if(PowerManager.ACTION_POWER_SAVE_WHITELIST_CHANGED.equals(action)) {
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_WHITELIST_CHANGED));
} else if(INTENT_SCHEDULEMODE_ALARM.equals(action)) {
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_SCHEDULEMODE_ALARM));
} else {
//亮灭屏时，发送MSG_DEVICE_STATE_CHANGED
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_DEVICE_STATE_CHANGED, intent));
}
}
}, intentFilter); case MSG_DEVICE_STATE_CHANGED:
handleDeviceStateChanged((Intent)msg.obj);
break;PowerContorller.java-->handleDeviceStateChanged()
private void handleDeviceStateChanged(Intent intent) {
String action = intent.getAction();
boolean oldScreenOn = mScreenOn;
boolean oldMobileConnected = mMobileConnected;
boolean oldCharging = mCharging;
if (DEBUG) Slog.d(TAG, "- handleDeviceStateChanged() E -, action: " + action);
if (action.equals(Intent.ACTION_SCREEN_ON)) {
mScreenOn = true;
} else if (action.equals(Intent.ACTION_SCREEN_OFF)) {
mScreenOn = false;
} else if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
boolean bNoConnection = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
if (!bNoConnection) {
int networkType = intent.getIntExtra(ConnectivityManager.EXTRA_NETWORK_TYPE, ConnectivityManager.TYPE_NONE);
mMobileConnected = ConnectivityManager.isNetworkTypeMobile(networkType);
mWifiConnected = ConnectivityManager.isNetworkTypeWifi(networkType);
} else {
mMobileConnected = false;
mWifiConnected = false;
}
} else if (action.equals(Intent.ACTION_BATTERY_CHANGED)) {
int pluggedType = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0);
mCharging = (0 != intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0));
if (DEBUG) Slog.d(TAG, "pluggedType:" + pluggedType + " mCharging:" + mCharging);
updateBatteryLevelLow(false);
updatePowerSaveMode();
} else if (action.equals(PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED)) {
try {
notifyDozeStateChanged();
} catch (Exception e) {
// fall through
}
return;
}
if (DEBUG_MORE) Slog.d(TAG, "handleDeviceStateChanged: mCharging:" + mCharging
+ " mScreenOn:" + mScreenOn + " mMobileConnected:" + mMobileConnected);
boolean bScreenChanged = (oldScreenOn != mScreenOn);
boolean bConnectionChanged = (oldMobileConnected != mMobileConnected);
boolean bChargingChanged = (oldCharging != mCharging);
if (DEBUG) Slog.d(TAG, "handleDeviceStateChanged: bScreenChanged:" + bScreenChanged
+ " bConnectionChanged:" + bConnectionChanged + " bChargingChanged:" + bChargingChanged);
if (bScreenChanged || bConnectionChanged || bChargingChanged) {
checkPowerGuruInterval();
}
if (bScreenChanged || bChargingChanged) {
updateAppStateInfoForDeviceStateChanged();
}
if (bScreenChanged)
mRecogAlgorithm.reportDeviceState(RecogAlgorithm.DEVICE_STATE_TYPE_SCREEN, mScreenOn);
if (bChargingChanged) {
mRecogAlgorithm.reportDeviceState(RecogAlgorithm.DEVICE_STATE_TYPE_CHARGING, mCharging);
}
// if in standby state, trigger a delay MSG_CHECK operation
if (!mScreenOn && !mCharging) {
msgHandler.removeMessages(MSG_CHECK);
msgHandler.sendMessageDelayed(msgHandler.obtainMessage(MSG_CHECK), SCREENOFF_CHECK_INTERVAL);
}
}重点看MSG_CHECK
case MSG_CHECK:
checkAllAppStateInfo();
break;PowerContorller.java-->checkAllAppStateInfo()
private void checkAllAppStateInfo() {
if (DEBUG) Slog.d(TAG, "- checkAllAppStateInfo() E -");
if (DEBUG) Slog.d(TAG, "mCharging:" + mCharging + " mScreenOn:" + mScreenOn + " mMobileConnected:" + mMobileConnected);
//set next check
//msgHandler.removeMessages(MSG_CHECK);
//msgHandler.sendMessageDelayed(msgHandler.obtainMessage(MSG_CHECK), CHECK_INTERVAL);
scheduleAlarmLocked(CHECK_INTERVAL);
if (mCharging || mScreenOn)
return;
checkSystemUpTime();
boolean bChanged = false;
// Note:use the same now elapsed time for all the AppStateInfo
// otherwise, when checking app Parole, some app may have not
// opportunity to exit app standby.
long now = SystemClock.elapsedRealtime();
updatePowerSaveMode();
try {
final List<UserInfo> users = mUserManager.getUsers();
for (int ui = users.size() - 1; ui >= 0; ui--) {
UserInfo user = users.get(ui);
if (DEBUG) Slog.d(TAG, "- checkAllAppStateInfo() for user: " + user.id);
final ArrayMap<String, AppState> appStateInfoList = mAppStateInfoCollector.getAppStateInfoList(user.id);
for (int i=0;i<appStateInfoList.size();i++) {
AppState appState = appStateInfoList.valueAt(i);
//let app to be parole
mAppIdleHelper.checkAppParole(appState, now);
// check app state info
if (checkAppStateInfo(appState, now)) {
//可以被清理
bChanged = true;
}
}
}
} catch (Exception e) {
}
// note AppidleHelper all check done
mAppIdleHelper.noteCheckAllAppStateInfoDone();
// note mWakelockConstraintHelper all check done
mWakelockConstraintHelper.noteCheckAllAppStateInfoDone();
//send notification to powerguru & appstandby
// changed for bug#891620
//if (bChanged) msgHandler.sendMessage(msgHandler.obtainMessage(MSG_NOTIFY_CHANGED));
if (bChanged) notifyChanged();
if (needCheckNetworkConnection(now)) {
if (DEBUG) Slog.d(TAG, "- checkNetworkConnection() in checkAllAppStateInfo -");
checkNetworkConnection(true);
}
// check doze state
checkDozeState();
}
PowerContorller.java-->checkAppStateInfo()
private boolean checkAppStateInfo(AppState appState, final long nowELAPSED) {
boolean bChanged = false;
// check app state info
for (int i = 0; i < mHelpers.size(); i++) {
PowerSaveHelper helper = mHelpers.get(i);
if (helper.checkAppStateInfo(appState, nowELAPSED)) {
bChanged = true;
}
}
return bChanged;
}BackgroundCleanHelper.java -->checkAppStateInfo()
/*
* check this app should be constrained or not
* return true if this app should be constrained
* others return false
*/
boolean checkAppStateInfo(AppState appState, final long nowELAPSED) {
ArrayMap<String, Integer> mForceStopAppList = getForceStopAppList(appState.mUserId);
boolean bChanged = false;
if (canBeConstrained(appState)) {
bChanged = true;
//可以被清理的进程放入到mForceStopAppList
if (!mForceStopAppList.containsKey(appState.mPackageName)) {
mForceStopAppList.put(appState.mPackageName, appState.mUserId);
if (DEBUG) Slog.d(TAG, "checkAppStateInfo(), add " + appState.mPackageName + " to forcestop list");
}
} else {
// if already put it in mForceStopAppList, just remove
mForceStopAppList.remove(appState.mPackageName);
}
return bChanged;
}
现在就到核心方法了canBeConstrained(),我们来重点看下
boolean canBeConstrained(AppState appState) {
// if this function is disabled, just return false
if (!mEnabled) return false;
// set bgclean timer
long delayMs = SystemClock.elapsedRealtime() - mStandbyStartTime - DOCLEAN_TIMEOUT;
if (delayMs < 0) {
if (!mAlarmSet) {
if (DEBUG) Slog.d(TAG, "canBeConstrained(), set alarm");
// not use wake up alarm, otherwise a cts case of sensor will fail.
mAlarmManager.set(AlarmManager.ELAPSED_REALTIME,
mStandbyStartTime + DOCLEAN_TIMEOUT, TAG, mAlarmListener, mHandler);
mAlarmSet = true;
}
return false;
}
// not a system app
if (isSystemApp(appState)) { // system app
return false;
}
// app not exist
if ((appState.mProcState == ActivityManager.PROCESS_STATE_CACHED_EMPTY && Event.NONE == appState.mState)
|| appState.mProcState == ActivityManager.PROCESS_STATE_NONEXISTENT) {
return false;
}
// avoid kill input method
if (appState.mIsEnabledInputMethod)
return false;
if (isImportantPrefferedApp(appState.mPackageName))
return false;
boolean isVisible = false;
int index = mVisibleAppList.indexOf(appState.mPackageName);
if (index >= 0) {
isVisible = true;
}
// not a visible app
if (isVisible) {
return false;
}
// playing music App can not be constrained
if (isPlayingMusic(appState)) {
if (DEBUG) Slog.d(TAG, "canBeConstrained: " + appState.mPackageName + " Music is playing");
return false;
}
// doing download App can not be constrained
if (isDoingDownload(appState)) {
if (DEBUG) Slog.d(TAG, "canBeConstrained: " + appState.mPackageName
+ " Doing Download");
return false;
}
/** @hide Process is in the background, but it can't restore its state so we want
* to try to avoid killing it. */
if (appState.mProcState == ActivityManager.PROCESS_STATE_HEAVY_WEIGHT) {
return false;
}
// not app in whitelist
if (inCommonWhiteAppList(appState.mPackageName)) {
return false;
}
if (mLockScreen_WhiteList.contains(appState.mPackageName)) {
if (DEBUG) Slog.d(TAG, "bgclean CanBeConstrained: " + appState.mPackageName + " in my lockscreen whitelist");
return false;
} else if (mLockScreen_BlackList.contains(appState.mPackageName)) {
if (DEBUG) Slog.d(TAG, "bgclean CanBeConstrained: " + appState.mPackageName + " in my lockscreen blacklist");
return true;
}
// this app is avoid killing
if (appState.mAvoidKilling) return false;
// message App can not be constrained
// for bug#787547 don't kill preset message app
if (isMessageApp(appState)
||mAbsDeviceIdleController.isInPresetWhiteAppList(appState.mPackageName)
) {
if (DEBUG) Slog.d(TAG, "canBeConstrained: " + appState.mPackageName + " Message App");
return false;
}
// in low power mode, we will clean more bg app
if (PowerManagerEx.MODE_LOWPOWER == mPowerSaveMode) {
if (DEBUG) Slog.d(TAG, "canBeConstrained, low power mode clean, appname: " + appState.mPackageName + ", time diff: " + (SystemClock.elapsedRealtime() - mStandbyStartTime)
+ ", procState: " + appState.mProcState);
if (LOWPOWER_DOCLEAN_THRESHOLD <= SystemClock.elapsedRealtime() - mStandbyStartTime) {
if (appState.mProcState > ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND) {
if (DEBUG) Slog.d(TAG, "canBeConstrained: low power mode clean, " + appState.mPackageName);
return true;
}
}
}
// doing download App can not be constrained
if (isDoingDownload(appState)) {
if (DEBUG) Slog.d(TAG, "canBeConstrained: " + appState.mPackageName
+ " Doing Download (mUsedTimeSliceCount:" + appState.mUsedTimeSliceCount + ")");
// download is checked using a time slice (default 30s)
// if the count of time slice using to complete detecting download
// is >= 1, then we can be sure that user use this app doing download before standby
// in this case, we will avoid kill this app
if (appState.mUsedTimeSliceCount >=1 ) {
appState.mAvoidKilling = true;
}
return false;
}
long nowELAPSED = SystemClock.elapsedRealtime();
long now = System.currentTimeMillis(); // wall time
long fromBootup = now - nowELAPSED; // wall time
long idleDuration = 0;
long idleDurationBeforeStandby = 0;
boolean hasLaunched = false;
boolean hasNotification = false;
boolean mayPlayingMusic = false;
boolean launcherApp = isLauncherApp(appState.mPackageName);
// FixMe: if we has more exact method to jude app playing music, then we don't need to do this
mayPlayingMusic = mayBePlayingMusic(appState);
if (DEBUG) Slog.d(TAG, "pkg: " + appState.mPackageName
+ " flags:" + Integer.toHexString(appState.mFlags)
+ " ProcState:" + Util.ProcState2Str(appState.mProcState));
if (appState.mLastLaunchTime > 0) hasLaunched = true;
idleDuration = (appState.mLastTimeUsed > 0 ? (nowELAPSED -appState.mLastTimeUsed) : -1);
idleDurationBeforeStandby = (mStandbyStartTime > appState.mLastTimeUsed ? (mStandbyStartTime -appState.mLastTimeUsed) : 0);
hasNotification = hasActiveNotification(appState);
if (DEBUG) Slog.d(TAG, "STATE: pkg:" + appState.mPackageName
+ " idle for:" + idleDuration
+ " idleDurationBeforeStandby:" + idleDurationBeforeStandby
+ " hasLaunched:" + hasLaunched
+ " isVisable:" + isVisible
+ " hasNotification:" + hasNotification
+ " mayPlayingMusic:" + mayPlayingMusic
+ " launcherApp:" + launcherApp);
// if app is launched by user
// and may be playing music, then don't kill this app
if (hasLaunched && mayPlayingMusic) {
return false;
}
/*
* 7. ((app not lauched by user && app has not notification) ||
* (app not launched by user && app has notification && idle time > 1 h after standby) )
*/
if ((!hasLaunched && !hasNotification)
|| (!hasLaunched && hasNotification && idleDuration > (idleDurationBeforeStandby + FORCE_STOP_IDLE_THRESHOLD1) )
) {
return true;
}
/*
* 8. ((app launched by user && app has not notification && idle time > 2h) ||
* (app launched by user && app has notification && && idle time > 4h after standby))
*/
if (hasLaunched) {
int currentActiveLaunchedCount = mAppStateInfoCollector.getCountOfActiveLaunchedApps(mCurrentUserId);
if (DEBUG) Slog.d(TAG, "currentActiveLaunchedCount:" + currentActiveLaunchedCount);
if (!launcherApp && currentActiveLaunchedCount > MAX_LAUNCHED_APP_KEEP) {
if ((!hasNotification && idleDuration > ( FORCE_STOP_IDLE_THRESHOLD2))
|| (hasNotification && !appState.mHasNoClearNotification
&& idleDuration > ( idleDurationBeforeStandby + FORCE_STOP_IDLE_THRESHOLD3))
) {
return true;
}
}
}
return false;
}
isSystemApp(),判断是否是系统应用
private boolean isSystemApp(AppState appState) {
if (appState != null) {
return ((appState.mFlags & (ApplicationInfo.FLAG_UPDATED_SYSTEM_APP | ApplicationInfo.FLAG_SYSTEM)) != 0
|| appState.mFlags == 0);
} else {
return true; // default
}
}appState.mIsEnabledInputMethod 判断是否是输入法
我们看下这个值是怎么设置的
AppState retVal = new AppState(packageName, userId, uid, stateEvent, procState, flags);
// check if is input method
retVal.mIsEnabledInputMethod = isEnabledIMEApp(packageName);
// if this app is a input Method
private boolean isEnabledIMEApp(String pkgName){
if (pkgName == null) return false;
IInputMethodManager service = IInputMethodManager.Stub.asInterface(
ServiceManager.getService(Context.INPUT_METHOD_SERVICE));
List<InputMethodInfo> inputMethods;
try {
inputMethods = service.getEnabledInputMethodList();
} catch (RemoteException e) {
return false;
}
if (inputMethods == null || inputMethods.size() == 0) return false;
for (InputMethodInfo info : inputMethods){
if (info == null || info.getPackageName() == null) continue;
if (info.getPackageName().equals(pkgName)) return true;
}
return false;
}isVisible判断是否有启动的应用
boolean isVisible = false;
int index = mVisibleAppList.indexOf(appState.mPackageName);
if (index >= 0) {
isVisible = true;
}
// not a visible app
if (isVisible) {
return false;
}从代码可以看出isVisible是通过mVisibleAppList判断的
private void updateVisibleActivities() {
try {
// Clear first
mVisibleAppList.clear();
List<IBinder> activityTokens = null;
// Let's get top activities from all visible stacks
activityTokens = LocalServices.getService(ActivityManagerInternal.class).getTopVisibleActivities();
final int count = activityTokens.size();
for (int i = 0; i < count; i++) {
IBinder topActivity = activityTokens.get(i);
try {
String packageName = mActivityManager.getPackageForToken(topActivity);
if (packageName != null) {
mVisibleAppList.add(packageName);
Slog.d(TAG, "VisibleActivities:" + packageName);
}
} catch (RemoteException e) {
}
}
} catch (Exception e) {
e.printStackTrace();
}
Slog.d(TAG, "updateVisibleActivities done");
}isPlayingMusic 判断应用是否正在播放音乐
这个流程看了下有点儿负责，等有时间单独写个总结分析
isDoingDownload 判断应用是否正在下载
private boolean isAppDoingDownloadInternal(AppState state) {
int procState = state.mProcState;
//if (procState > ActivityManager.PROCESS_STATE_FOREGROUND_SERVICE)
// return false;
boolean doingDownload = false;
if (state.mRxBytesWhenStartEvaluated > 0) {
long now = SystemClock.elapsedRealtime();
long currentRxBytes = TrafficStats.getUidRxBytes(state.mUid);
long secondsSpended = (now - state.mTimeStampForRxBytes)/1000;
if (DEBUG) Slog.d(TAG, "uid:" + state.mUid + " packageName:" + state.mPackageName
+ " currentRxBytes:" + currentRxBytes + " startRxBytes:" + state.mRxBytesWhenStartEvaluated
+ " timespended: " + secondsSpended + " avgRate:" + (currentRxBytes - state.mRxBytesWhenStartEvaluated)/(secondsSpended+1));
if (currentRxBytes - state.mRxBytesWhenStartEvaluated
> (MIN_DATA_RATE * secondsSpended) || (secondsSpended < DOWNLOAD_CHECKING_MIN_TIME_SPAN))
doingDownload = true;
if (doingDownload && secondsSpended > DOWNLOAD_CHECKING_MIN_TIME_SPAN) {
long systemUpDuration = secondsSpended*1000;
if (mLastSystemUpTimeStamp > 0)
systemUpDuration = (now - mLastSystemUpTimeStamp);
if (DEBUG) Slog.d(TAG, "systemUpDuration:" + systemUpDuration + " secondsSpended:" + secondsSpended);
if (systemUpDuration < (secondsSpended - 2 *SYSTEM_UP_CHECK_INTERVAL)) {
if (DEBUG) Slog.d(TAG, "systemUpDuration:" + systemUpDuration + "but secondsSpended:" + secondsSpended
+ " clear download flag!!");
doingDownload = false;
}
}
//Download state changed!!
if (state.mDoingDownload != doingDownload) {
mDownloadChangeCount++;
msgHandler.sendMessage(msgHandler.obtainMessage(MSG_DOWNLOAD_STATE_CHANGED, (doingDownload?1:0), 0, state));
}
if (doingDownload) {
if (secondsSpended >= DOWNLOAD_CHECKING_MIN_TIME_SPAN) {
state.mRxBytesWhenStartEvaluated = currentRxBytes;
state.mTimeStampForRxBytes = SystemClock.elapsedRealtime();
state.mUsedTimeSliceCount++;
}
return true;
}
}
return false;
}
canBeConstrained()分析完后，再回头看看checkAllAppStateInfo()-->notifyChanged()
private void notifyChanged() {
if (DEBUG) Slog.d(TAG, "- notifyChanged() E -");
for (int i = 0; i < mHelpers.size(); i++) {
PowerSaveHelper helper = mHelpers.get(i);
helper.applyConstrain();
}
}BackgroundCleanHelper.java-->notifyChanged()
void applyConstrain() {
for (int index=mForceStopAppListForUsers.size()-1; index>=0; index--) {
ArrayMap<String, Integer> mForceStopAppList = mForceStopAppListForUsers.valueAt(index);
try {
for (int i=0;i<mForceStopAppList.size();i++) {
String pkgName = mForceStopAppList.keyAt(i);
int userId = mForceStopAppList.valueAt(i);
try {
//调用forceStopPackage清理进程
mActivityManager.forceStopPackage(pkgName, userId);
AppState appState = mAppStateInfoCollector.getAppState(pkgName, userId);
if (appState != null) {
// do some cleaning for appState
appState.clearLaunchInfo();
} else {
Slog.w(TAG, "null appState for " + pkgName + " userId:" + userId);
}
Slog.d(TAG, "force stop:" + pkgName + " userId:" + userId);
ArrayMap<String, Integer> mStoppedAppList = getStoppedAppList(userId);
// add to stopped app list
mStoppedAppList.put(pkgName, userId);
} catch (RemoteException e) {
}
}
} catch (Exception e) {
e.printStackTrace();
}
mForceStopAppList.clear();