/* * Copyright (C) 2006-2007 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. */ package com.android.server.am; import android.bluetooth.BluetoothActivityEnergyInfo; import android.bluetooth.BluetoothAdapter; import android.content.Context; import android.content.pm.ApplicationInfo; import android.content.pm.PackageManager; import android.net.wifi.IWifiManager; import android.net.wifi.WifiActivityEnergyInfo; import android.os.BatteryStats; import android.os.Binder; import android.os.Handler; import android.os.IBinder; import android.os.Looper; import android.os.Message; import android.os.Parcel; import android.os.ParcelFileDescriptor; import android.os.ParcelFormatException; import android.os.PowerManagerInternal; import android.os.Process; import android.os.RemoteException; import android.os.ServiceManager; import android.os.SystemClock; import android.os.UserHandle; import android.os.WorkSource; import android.telephony.DataConnectionRealTimeInfo; import android.telephony.SignalStrength; import android.telephony.TelephonyManager; import android.util.IntArray; import android.util.Slog; import android.util.TimeUtils; import com.android.internal.annotations.GuardedBy; import com.android.internal.app.IBatteryStats; import com.android.internal.os.BatteryStatsHelper; import com.android.internal.os.BatteryStatsImpl; import com.android.internal.os.PowerProfile; import com.android.server.FgThread; import com.android.server.LocalServices; import java.io.File; import java.io.FileDescriptor; import java.io.IOException; import java.io.PrintWriter; import java.nio.ByteBuffer; import java.nio.CharBuffer; import java.nio.charset.CharsetDecoder; import java.nio.charset.CodingErrorAction; import java.nio.charset.StandardCharsets; import java.util.List; /** * All information we are collecting about things that can happen that impact * battery life. */ public final class BatteryStatsService extends IBatteryStats.Stub implements PowerManagerInternal.LowPowerModeListener { static final String TAG = "BatteryStatsService"; static IBatteryStats sService; final BatteryStatsImpl mStats; final BatteryStatsHandler mHandler; Context mContext; PowerManagerInternal mPowerManagerInternal; final int UPDATE_CPU = 0x01; final int UPDATE_WIFI = 0x02; final int UPDATE_RADIO = 0x04; final int UPDATE_BT = 0x08; final int UPDATE_ALL = UPDATE_CPU | UPDATE_WIFI | UPDATE_RADIO | UPDATE_BT; class BatteryStatsHandler extends Handler implements BatteryStatsImpl.ExternalStatsSync { public static final int MSG_SYNC_EXTERNAL_STATS = 1; public static final int MSG_WRITE_TO_DISK = 2; private int mUpdateFlags = 0; private IntArray mUidsToRemove = new IntArray(); public BatteryStatsHandler(Looper looper) { super(looper); } @Override public void handleMessage(Message msg) { switch (msg.what) { case MSG_SYNC_EXTERNAL_STATS: final int updateFlags; synchronized (this) { removeMessages(MSG_SYNC_EXTERNAL_STATS); updateFlags = mUpdateFlags; mUpdateFlags = 0; } updateExternalStats((String)msg.obj, updateFlags); // other parts of the system could be calling into us // from mStats in order to report of changes. We must grab the mStats // lock before grabbing our own or we'll end up in a deadlock. synchronized (mStats) { synchronized (this) { final int numUidsToRemove = mUidsToRemove.size(); for (int i = 0; i < numUidsToRemove; i++) { mStats.removeIsolatedUidLocked(mUidsToRemove.get(i)); } } mUidsToRemove.clear(); } break; case MSG_WRITE_TO_DISK: updateExternalStats("write", UPDATE_ALL); synchronized (mStats) { mStats.writeAsyncLocked(); } break; } } @Override public void scheduleSync(String reason) { synchronized (this) { scheduleSyncLocked(reason, UPDATE_ALL); } } @Override public void scheduleWifiSync(String reason) { synchronized (this) { scheduleSyncLocked(reason, UPDATE_WIFI); } } @Override public void scheduleCpuSyncDueToRemovedUid(int uid) { synchronized (this) { scheduleSyncLocked("remove-uid", UPDATE_CPU); mUidsToRemove.add(uid); } } private void scheduleSyncLocked(String reason, int updateFlags) { if (mUpdateFlags == 0) { sendMessage(Message.obtain(this, MSG_SYNC_EXTERNAL_STATS, reason)); } mUpdateFlags |= updateFlags; } } BatteryStatsService(File systemDir, Handler handler) { // Our handler here will be accessing the disk, use a different thread than // what the ActivityManagerService gave us (no I/O on that one!). mHandler = new BatteryStatsHandler(FgThread.getHandler().getLooper()); // BatteryStatsImpl expects the ActivityManagerService handler, so pass that one through. mStats = new BatteryStatsImpl(systemDir, handler, mHandler); } public void publish(Context context) { mContext = context; ServiceManager.addService(BatteryStats.SERVICE_NAME, asBinder()); mStats.setNumSpeedSteps(new PowerProfile(mContext).getNumSpeedSteps()); mStats.setRadioScanningTimeout(mContext.getResources().getInteger( com.android.internal.R.integer.config_radioScanningTimeout) * 1000L); mStats.setPowerProfile(new PowerProfile(context)); } /** * At the time when the constructor runs, the power manager has not yet been * initialized. So we initialize the low power observer later. */ public void initPowerManagement() { mPowerManagerInternal = LocalServices.getService(PowerManagerInternal.class); mPowerManagerInternal.registerLowPowerModeObserver(this); mStats.notePowerSaveMode(mPowerManagerInternal.getLowPowerModeEnabled()); (new WakeupReasonThread()).start(); } public void shutdown() { Slog.w("BatteryStats", "Writing battery stats before shutdown..."); updateExternalStats("shutdown", UPDATE_ALL); synchronized (mStats) { mStats.shutdownLocked(); } } public static IBatteryStats getService() { if (sService != null) { return sService; } IBinder b = ServiceManager.getService(BatteryStats.SERVICE_NAME); sService = asInterface(b); return sService; } @Override public void onLowPowerModeChanged(boolean enabled) { synchronized (mStats) { mStats.notePowerSaveMode(enabled); } } /** * @return the current statistics object, which may be modified * to reflect events that affect battery usage. You must lock the * stats object before doing anything with it. */ public BatteryStatsImpl getActiveStatistics() { return mStats; } /** * Schedules a write to disk to occur. This will cause the BatteryStatsImpl * object to update with the latest info, then write to disk. */ public void scheduleWriteToDisk() { mHandler.sendEmptyMessage(BatteryStatsHandler.MSG_WRITE_TO_DISK); } // These are for direct use by the activity manager... /** * Remove a UID from the BatteryStats and BatteryStats' external dependencies. */ void removeUid(int uid) { synchronized (mStats) { mStats.removeUidStatsLocked(uid); } } void addIsolatedUid(int isolatedUid, int appUid) { synchronized (mStats) { mStats.addIsolatedUidLocked(isolatedUid, appUid); } } void removeIsolatedUid(int isolatedUid, int appUid) { synchronized (mStats) { mStats.scheduleRemoveIsolatedUidLocked(isolatedUid, appUid); } } void noteProcessStart(String name, int uid) { synchronized (mStats) { mStats.noteProcessStartLocked(name, uid); } } void noteProcessCrash(String name, int uid) { synchronized (mStats) { mStats.noteProcessCrashLocked(name, uid); } } void noteProcessAnr(String name, int uid) { synchronized (mStats) { mStats.noteProcessAnrLocked(name, uid); } } void noteProcessState(String name, int uid, int state) { synchronized (mStats) { mStats.noteProcessStateLocked(name, uid, state); } } void noteProcessFinish(String name, int uid) { synchronized (mStats) { mStats.noteProcessFinishLocked(name, uid); } } // Public interface... public byte[] getStatistics() { mContext.enforceCallingPermission( android.Manifest.permission.BATTERY_STATS, null); //Slog.i("foo", "SENDING BATTERY INFO:"); //mStats.dumpLocked(new LogPrinter(Log.INFO, "foo", Log.LOG_ID_SYSTEM)); Parcel out = Parcel.obtain(); updateExternalStats("get-stats", UPDATE_ALL); synchronized (mStats) { mStats.writeToParcel(out, 0); } byte[] data = out.marshall(); out.recycle(); return data; } public ParcelFileDescriptor getStatisticsStream() { mContext.enforceCallingPermission( android.Manifest.permission.BATTERY_STATS, null); //Slog.i("foo", "SENDING BATTERY INFO:"); //mStats.dumpLocked(new LogPrinter(Log.INFO, "foo", Log.LOG_ID_SYSTEM)); Parcel out = Parcel.obtain(); updateExternalStats("get-stats", UPDATE_ALL); synchronized (mStats) { mStats.writeToParcel(out, 0); } byte[] data = out.marshall(); out.recycle(); try { return ParcelFileDescriptor.fromData(data, "battery-stats"); } catch (IOException e) { Slog.w(TAG, "Unable to create shared memory", e); return null; } } public boolean isCharging() { synchronized (mStats) { return mStats.isCharging(); } } public long computeBatteryTimeRemaining() { synchronized (mStats) { long time = mStats.computeBatteryTimeRemaining(SystemClock.elapsedRealtime()); return time >= 0 ? (time/1000) : time; } } public long computeChargeTimeRemaining() { synchronized (mStats) { long time = mStats.computeChargeTimeRemaining(SystemClock.elapsedRealtime()); return time >= 0 ? (time/1000) : time; } } public void noteEvent(int code, String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteEventLocked(code, name, uid); } } public void noteSyncStart(String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteSyncStartLocked(name, uid); } } public void noteSyncFinish(String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteSyncFinishLocked(name, uid); } } public void noteJobStart(String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteJobStartLocked(name, uid); } } public void noteJobFinish(String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteJobFinishLocked(name, uid); } } public void noteAlarmStart(String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteAlarmStartLocked(name, uid); } } public void noteAlarmFinish(String name, int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteAlarmFinishLocked(name, uid); } } public void noteStartWakelock(int uid, int pid, String name, String historyName, int type, boolean unimportantForLogging) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStartWakeLocked(uid, pid, name, historyName, type, unimportantForLogging, SystemClock.elapsedRealtime(), SystemClock.uptimeMillis()); } } public void noteStopWakelock(int uid, int pid, String name, String historyName, int type) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStopWakeLocked(uid, pid, name, historyName, type, SystemClock.elapsedRealtime(), SystemClock.uptimeMillis()); } } public void noteStartWakelockFromSource(WorkSource ws, int pid, String name, String historyName, int type, boolean unimportantForLogging) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStartWakeFromSourceLocked(ws, pid, name, historyName, type, unimportantForLogging); } } public void noteChangeWakelockFromSource(WorkSource ws, int pid, String name, String historyName, int type, WorkSource newWs, int newPid, String newName, String newHistoryName, int newType, boolean newUnimportantForLogging) { enforceCallingPermission(); synchronized (mStats) { mStats.noteChangeWakelockFromSourceLocked(ws, pid, name, historyName, type, newWs, newPid, newName, newHistoryName, newType, newUnimportantForLogging); } } public void noteStopWakelockFromSource(WorkSource ws, int pid, String name, String historyName, int type) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStopWakeFromSourceLocked(ws, pid, name, historyName, type); } } public void noteStartSensor(int uid, int sensor) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStartSensorLocked(uid, sensor); } } public void noteStopSensor(int uid, int sensor) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStopSensorLocked(uid, sensor); } } public void noteVibratorOn(int uid, long durationMillis) { enforceCallingPermission(); synchronized (mStats) { mStats.noteVibratorOnLocked(uid, durationMillis); } } public void noteVibratorOff(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteVibratorOffLocked(uid); } } public void noteStartGps(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStartGpsLocked(uid); } } public void noteStopGps(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteStopGpsLocked(uid); } } public void noteScreenState(int state) { enforceCallingPermission(); synchronized (mStats) { mStats.noteScreenStateLocked(state); } } public void noteScreenBrightness(int brightness) { enforceCallingPermission(); synchronized (mStats) { mStats.noteScreenBrightnessLocked(brightness); } } public void noteUserActivity(int uid, int event) { enforceCallingPermission(); synchronized (mStats) { mStats.noteUserActivityLocked(uid, event); } } public void noteWakeUp(String reason, int reasonUid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWakeUpLocked(reason, reasonUid); } } public void noteInteractive(boolean interactive) { enforceCallingPermission(); synchronized (mStats) { mStats.noteInteractiveLocked(interactive); } } public void noteConnectivityChanged(int type, String extra) { enforceCallingPermission(); synchronized (mStats) { mStats.noteConnectivityChangedLocked(type, extra); } } public void noteMobileRadioPowerState(int powerState, long timestampNs) { enforceCallingPermission(); synchronized (mStats) { mStats.noteMobileRadioPowerState(powerState, timestampNs); } } public void notePhoneOn() { enforceCallingPermission(); synchronized (mStats) { mStats.notePhoneOnLocked(); } } public void notePhoneOff() { enforceCallingPermission(); synchronized (mStats) { mStats.notePhoneOffLocked(); } } public void notePhoneSignalStrength(SignalStrength signalStrength) { enforceCallingPermission(); synchronized (mStats) { mStats.notePhoneSignalStrengthLocked(signalStrength); } } public void notePhoneDataConnectionState(int dataType, boolean hasData) { enforceCallingPermission(); synchronized (mStats) { mStats.notePhoneDataConnectionStateLocked(dataType, hasData); } } public void notePhoneState(int state) { enforceCallingPermission(); int simState = TelephonyManager.getDefault().getSimState(); synchronized (mStats) { mStats.notePhoneStateLocked(state, simState); } } public void noteWifiOn() { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiOnLocked(); } } public void noteWifiOff() { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiOffLocked(); } } public void noteStartAudio(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteAudioOnLocked(uid); } } public void noteStopAudio(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteAudioOffLocked(uid); } } public void noteStartVideo(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteVideoOnLocked(uid); } } public void noteStopVideo(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteVideoOffLocked(uid); } } public void noteResetAudio() { enforceCallingPermission(); synchronized (mStats) { mStats.noteResetAudioLocked(); } } public void noteResetVideo() { enforceCallingPermission(); synchronized (mStats) { mStats.noteResetVideoLocked(); } } public void noteFlashlightOn(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteFlashlightOnLocked(uid); } } public void noteFlashlightOff(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteFlashlightOffLocked(uid); } } public void noteStartCamera(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteCameraOnLocked(uid); } } public void noteStopCamera(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteCameraOffLocked(uid); } } public void noteResetCamera() { enforceCallingPermission(); synchronized (mStats) { mStats.noteResetCameraLocked(); } } public void noteResetFlashlight() { enforceCallingPermission(); synchronized (mStats) { mStats.noteResetFlashlightLocked(); } } @Override public void noteWifiRadioPowerState(int powerState, long tsNanos) { enforceCallingPermission(); // There was a change in WiFi power state. // Collect data now for the past activity. synchronized (mStats) { if (mStats.isOnBattery()) { final String type = (powerState == DataConnectionRealTimeInfo.DC_POWER_STATE_HIGH || powerState == DataConnectionRealTimeInfo.DC_POWER_STATE_MEDIUM) ? "active" : "inactive"; mHandler.scheduleWifiSync("wifi-data: " + type); } mStats.noteWifiRadioPowerState(powerState, tsNanos); } } public void noteWifiRunning(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiRunningLocked(ws); } } public void noteWifiRunningChanged(WorkSource oldWs, WorkSource newWs) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiRunningChangedLocked(oldWs, newWs); } } public void noteWifiStopped(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiStoppedLocked(ws); } } public void noteWifiState(int wifiState, String accessPoint) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiStateLocked(wifiState, accessPoint); } } public void noteWifiSupplicantStateChanged(int supplState, boolean failedAuth) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiSupplicantStateChangedLocked(supplState, failedAuth); } } public void noteWifiRssiChanged(int newRssi) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiRssiChangedLocked(newRssi); } } public void noteFullWifiLockAcquired(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteFullWifiLockAcquiredLocked(uid); } } public void noteFullWifiLockReleased(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteFullWifiLockReleasedLocked(uid); } } public void noteWifiScanStarted(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiScanStartedLocked(uid); } } public void noteWifiScanStopped(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiScanStoppedLocked(uid); } } public void noteWifiMulticastEnabled(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiMulticastEnabledLocked(uid); } } public void noteWifiMulticastDisabled(int uid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiMulticastDisabledLocked(uid); } } public void noteFullWifiLockAcquiredFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteFullWifiLockAcquiredFromSourceLocked(ws); } } public void noteFullWifiLockReleasedFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteFullWifiLockReleasedFromSourceLocked(ws); } } public void noteWifiScanStartedFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiScanStartedFromSourceLocked(ws); } } public void noteWifiScanStoppedFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiScanStoppedFromSourceLocked(ws); } } public void noteWifiBatchedScanStartedFromSource(WorkSource ws, int csph) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiBatchedScanStartedFromSourceLocked(ws, csph); } } public void noteWifiBatchedScanStoppedFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiBatchedScanStoppedFromSourceLocked(ws); } } public void noteWifiMulticastEnabledFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiMulticastEnabledFromSourceLocked(ws); } } @Override public void noteWifiMulticastDisabledFromSource(WorkSource ws) { enforceCallingPermission(); synchronized (mStats) { mStats.noteWifiMulticastDisabledFromSourceLocked(ws); } } @Override public void noteNetworkInterfaceType(String iface, int networkType) { enforceCallingPermission(); synchronized (mStats) { mStats.noteNetworkInterfaceTypeLocked(iface, networkType); } } @Override public void noteNetworkStatsEnabled() { enforceCallingPermission(); synchronized (mStats) { mStats.noteNetworkStatsEnabledLocked(); } } @Override public void noteDeviceIdleMode(boolean enabled, String activeReason, int activeUid) { enforceCallingPermission(); synchronized (mStats) { mStats.noteDeviceIdleModeLocked(enabled, activeReason, activeUid); } } public void notePackageInstalled(String pkgName, int versionCode) { enforceCallingPermission(); synchronized (mStats) { mStats.notePackageInstalledLocked(pkgName, versionCode); } } public void notePackageUninstalled(String pkgName) { enforceCallingPermission(); synchronized (mStats) { mStats.notePackageUninstalledLocked(pkgName); } } public boolean isOnBattery() { return mStats.isOnBattery(); } @Override public void setBatteryState(final int status, final int health, final int plugType, final int level, final int temp, final int volt) { enforceCallingPermission(); // BatteryService calls us here and we may update external state. It would be wrong // to block such a low level service like BatteryService on external stats like WiFi. mHandler.post(new Runnable() { @Override public void run() { synchronized (mStats) { final boolean onBattery = plugType == BatteryStatsImpl.BATTERY_PLUGGED_NONE; if (mStats.isOnBattery() == onBattery) { // The battery state has not changed, so we don't need to sync external // stats immediately. mStats.setBatteryStateLocked(status, health, plugType, level, temp, volt); return; } } // Sync external stats first as the battery has changed states. If we don't sync // immediately here, we may not collect the relevant data later. updateExternalStats("battery-state", UPDATE_ALL); synchronized (mStats) { mStats.setBatteryStateLocked(status, health, plugType, level, temp, volt); } } }); } public long getAwakeTimeBattery() { mContext.enforceCallingOrSelfPermission( android.Manifest.permission.BATTERY_STATS, null); return mStats.getAwakeTimeBattery(); } public long getAwakeTimePlugged() { mContext.enforceCallingOrSelfPermission( android.Manifest.permission.BATTERY_STATS, null); return mStats.getAwakeTimePlugged(); } public void enforceCallingPermission() { if (Binder.getCallingPid() == Process.myPid()) { return; } mContext.enforcePermission(android.Manifest.permission.UPDATE_DEVICE_STATS, Binder.getCallingPid(), Binder.getCallingUid(), null); } final class WakeupReasonThread extends Thread { private static final int MAX_REASON_SIZE = 512; private CharsetDecoder mDecoder; private ByteBuffer mUtf8Buffer; private CharBuffer mUtf16Buffer; WakeupReasonThread() { super("BatteryStats_wakeupReason"); } public void run() { Process.setThreadPriority(Process.THREAD_PRIORITY_FOREGROUND); mDecoder = StandardCharsets.UTF_8 .newDecoder() .onMalformedInput(CodingErrorAction.REPLACE) .onUnmappableCharacter(CodingErrorAction.REPLACE) .replaceWith("?"); mUtf8Buffer = ByteBuffer.allocateDirect(MAX_REASON_SIZE); mUtf16Buffer = CharBuffer.allocate(MAX_REASON_SIZE); try { String reason; while ((reason = waitWakeup()) != null) { synchronized (mStats) { mStats.noteWakeupReasonLocked(reason); } } } catch (RuntimeException e) { Slog.e(TAG, "Failure reading wakeup reasons", e); } } private String waitWakeup() { mUtf8Buffer.clear(); mUtf16Buffer.clear(); mDecoder.reset(); int bytesWritten = nativeWaitWakeup(mUtf8Buffer); if (bytesWritten < 0) { return null; } else if (bytesWritten == 0) { return "unknown"; } // Set the buffer's limit to the number of bytes written. mUtf8Buffer.limit(bytesWritten); // Decode the buffer from UTF-8 to UTF-16. // Unmappable characters will be replaced. mDecoder.decode(mUtf8Buffer, mUtf16Buffer, true); mUtf16Buffer.flip(); // Create a String from the UTF-16 buffer. return mUtf16Buffer.toString(); } } private static native int nativeWaitWakeup(ByteBuffer outBuffer); private void dumpHelp(PrintWriter pw) { pw.println("Battery stats (batterystats) dump options:"); pw.println(" [--checkin] [--history] [--history-start] [--charged] [-c]"); pw.println(" [--daily] [--reset] [--write] [--new-daily] [--read-daily] [-h] []"); pw.println(" --checkin: format output for a checkin report."); pw.println(" --history: show only history data."); pw.println(" --history-start : show only history data starting at given time offset."); pw.println(" --charged: only output data since last charged."); pw.println(" --daily: only output full daily data."); pw.println(" --reset: reset the stats, clearing all current data."); pw.println(" --write: force write current collected stats to disk."); pw.println(" --new-daily: immediately create and write new daily stats record."); pw.println(" --read-daily: read-load last written daily stats."); pw.println(" : optional name of package to filter output by."); pw.println(" -h: print this help text."); pw.println("Battery stats (batterystats) commands:"); pw.println(" enable|disable