Adding idle maintenance service.
It is beneficial that there is a mechanism on the platform
to notify applications whether it is safe to perform somehow
expensive operations while the user is not using the device.
Thus, user experience will not be degraded. An example is
discarding of unused blocks on a mounted file system instead
of doing this on every write operation.
bug:8056794
Change-Id: I708bad9d3ce6c8f1d5a1c05c0abf46f81a3d464b
diff --git a/services/java/com/android/server/IdleMaintenanceService.java b/services/java/com/android/server/IdleMaintenanceService.java
new file mode 100644
index 0000000..a7442f6
--- /dev/null
+++ b/services/java/com/android/server/IdleMaintenanceService.java
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2013 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;
+
+import android.app.Activity;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.BatteryManager;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.PowerManager;
+import android.os.PowerManager.WakeLock;
+import android.os.SystemClock;
+import android.os.UserHandle;
+import android.util.Log;
+
+import java.util.Calendar;
+import java.util.TimeZone;
+
+/**
+ * This service observes the device state and when applicable sends
+ * broadcasts at the beginning and at the end of a period during which
+ * observers can perform idle maintenance tasks. Typical use of the
+ * idle maintenance is to perform somehow expensive tasks that can be
+ * postponed to a moment when they will not degrade user experience.
+ *
+ * The current implementation is very simple. The start of a maintenance
+ * window is announced if: the screen is off or showing a dream AND the
+ * battery level is more than twenty percent AND at least one hour passed
+ * since the screen went off or a dream started (i.e. since the last user
+ * activity).
+ *
+ * The end of a maintenance window is announced only if: a start was
+ * announced AND the screen turned on or a dream was stopped.
+ */
+public class IdleMaintenanceService extends BroadcastReceiver {
+
+ private final boolean DEBUG = false;
+
+ private static final String LOG_TAG = IdleMaintenanceService.class.getSimpleName();
+
+ private static final int LAST_USER_ACTIVITY_TIME_INVALID = -1;
+
+ private static final int MIN_IDLE_MAINTENANCE_START_BATTERY_LEVEL = 20; // percent
+
+ private static final long MIN_IDLE_MAINTENANCE_START_USER_INACTIVITY = 60 * 60 * 1000; // 1 hour
+
+ private final Intent mIdleMaintenanceStartIntent =
+ new Intent(Intent.ACTION_IDLE_MAINTENANCE_START);
+
+ private final Intent mIdleMaintenanceEndIntent =
+ new Intent(Intent.ACTION_IDLE_MAINTENANCE_END);
+
+ private final Context mContext;
+
+ private final WakeLock mWakeLock;
+
+ private final Handler mHandler;
+
+ private final Calendar mTempCalendar = Calendar.getInstance();
+
+ private final Calendar mLastIdleMaintenanceStartTime = Calendar.getInstance();
+
+ private long mLastUserActivityElapsedTimeMillis = LAST_USER_ACTIVITY_TIME_INVALID;
+
+ private int mBatteryLevel;
+
+ private boolean mIdleMaintenanceStarted;
+
+ public IdleMaintenanceService(Context context) {
+ mContext = context;
+
+ PowerManager powerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
+ mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, LOG_TAG);
+
+ mHandler = new Handler(mContext.getMainLooper());
+
+ // Move one day back so we can run maintenance the first day after starting.
+ final int prevDayOfYear = mLastIdleMaintenanceStartTime.get(Calendar.DAY_OF_YEAR) - 1;
+ mLastIdleMaintenanceStartTime.set(Calendar.DAY_OF_YEAR, prevDayOfYear);
+
+ register(mContext.getMainLooper());
+ }
+
+ public void register(Looper looper) {
+ IntentFilter intentFilter = new IntentFilter();
+
+ // Battery actions.
+ intentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
+
+ // Screen actions.
+ intentFilter.addAction(Intent.ACTION_SCREEN_ON);
+ intentFilter.addAction(Intent.ACTION_SCREEN_OFF);
+
+ // Dream actions.
+ intentFilter.addAction(Intent.ACTION_DREAMING_STARTED);
+ intentFilter.addAction(Intent.ACTION_DREAMING_STOPPED);
+
+ mContext.registerReceiverAsUser(this, UserHandle.ALL,
+ intentFilter, null, new Handler(looper));
+ }
+
+ private void updateIdleMaintenanceState() {
+ if (mIdleMaintenanceStarted) {
+ // Idle maintenance can be interrupted only by
+ // a change of the device state.
+ if (!deviceStatePermitsIdleMaintenance()) {
+ mIdleMaintenanceStarted = false;
+ sendIdleMaintenanceEndIntent();
+ }
+ } else if (deviceStatePermitsIdleMaintenance()
+ && lastUserActivityPermitsIdleMaintenanceStart()
+ && lastRunPermitsIdleMaintenanceStart()) {
+ mIdleMaintenanceStarted = true;
+ mLastIdleMaintenanceStartTime.setTimeInMillis(System.currentTimeMillis());
+ sendIdleMaintenanceStartIntent();
+ }
+ }
+
+ private void sendIdleMaintenanceStartIntent() {
+ if (DEBUG) {
+ Log.i(LOG_TAG, "Broadcasting " + Intent.ACTION_IDLE_MAINTENANCE_START);
+ }
+ mWakeLock.acquire();
+ mContext.sendOrderedBroadcastAsUser(mIdleMaintenanceStartIntent, UserHandle.ALL,
+ null, this, mHandler, Activity.RESULT_OK, null, null);
+ }
+
+ private void sendIdleMaintenanceEndIntent() {
+ if (DEBUG) {
+ Log.i(LOG_TAG, "Broadcasting " + Intent.ACTION_IDLE_MAINTENANCE_END);
+ }
+ mWakeLock.acquire();
+ mContext.sendOrderedBroadcastAsUser(mIdleMaintenanceEndIntent, UserHandle.ALL,
+ null, this, mHandler, Activity.RESULT_OK, null, null);
+ }
+
+ private boolean deviceStatePermitsIdleMaintenance() {
+ return (mLastUserActivityElapsedTimeMillis != LAST_USER_ACTIVITY_TIME_INVALID
+ && mBatteryLevel > MIN_IDLE_MAINTENANCE_START_BATTERY_LEVEL);
+ }
+
+ private boolean lastUserActivityPermitsIdleMaintenanceStart() {
+ return (SystemClock.elapsedRealtime() - mLastUserActivityElapsedTimeMillis
+ > MIN_IDLE_MAINTENANCE_START_USER_INACTIVITY);
+ }
+
+ private boolean lastRunPermitsIdleMaintenanceStart() {
+ Calendar now = mTempCalendar;
+ // Not setting the Locale since we do not care of locale
+ // specific properties such as the first day of the week.
+ now.setTimeZone(TimeZone.getDefault());
+ now.setTimeInMillis(System.currentTimeMillis());
+
+ Calendar lastRun = mLastIdleMaintenanceStartTime;
+ // Not setting the Locale since we do not care of locale
+ // specific properties such as the first day of the week.
+ lastRun.setTimeZone(TimeZone.getDefault());
+
+ return now.get(Calendar.DAY_OF_YEAR) != lastRun.get(Calendar.DAY_OF_YEAR);
+ }
+
+ @Override
+ public void onReceive(Context context, Intent intent) {
+ if (DEBUG) {
+ Log.i(LOG_TAG, intent.getAction());
+ }
+ String action = intent.getAction();
+ if (Intent.ACTION_BATTERY_CHANGED.equals(action)) {
+ final int maxBatteryLevel = intent.getExtras().getInt(BatteryManager.EXTRA_SCALE);
+ final int currBatteryLevel = intent.getExtras().getInt(BatteryManager.EXTRA_LEVEL);
+ mBatteryLevel = (int) (((float) maxBatteryLevel / 100) * currBatteryLevel);
+ } else if (Intent.ACTION_SCREEN_ON.equals(action)
+ || Intent.ACTION_DREAMING_STOPPED.equals(action)) {
+ mLastUserActivityElapsedTimeMillis = LAST_USER_ACTIVITY_TIME_INVALID;
+ } else if (Intent.ACTION_SCREEN_OFF.equals(action)
+ || Intent.ACTION_DREAMING_STARTED.equals(action)) {
+ mLastUserActivityElapsedTimeMillis = SystemClock.elapsedRealtime();
+ } else if (Intent.ACTION_IDLE_MAINTENANCE_START.equals(action)
+ || Intent.ACTION_IDLE_MAINTENANCE_END.equals(action)) {
+ mWakeLock.release();
+ return;
+ }
+ updateIdleMaintenanceState();
+ }
+}