Introduce a Lifecycle for system services

Provide an abstract class for system services to extend from,
similar to the android.app.Service.

This will allow services to receive events in a uniform way,
and will allow services to be created and started in the
correct order regardless of whether or not a particular
service exists.

Similar to android.app.Service, services are meant to implement
Binder interfaces as inner classes. This prevents services from
having incestuous access to each other and makes them use the
public API.

Change-Id: Iaacfee8d5f080a28d7cc606761f4624673ed390f

1 files changed, 18 insertions, 15 deletions

diff --git a/services/java/com/android/server/BatteryService.java b/services/java/com/android/server/BatteryService.java
index 5f3f894ca68e..cc9055dd480e 100644
--- a/services/java/com/android/server/BatteryService.java
+++ b/services/java/com/android/server/BatteryService.java
@@ -19,6 +19,8 @@ package com.android.server;
 import android.os.BatteryStats;
 import com.android.internal.app.IBatteryStats;
 import com.android.server.am.BatteryStatsService;
+import com.android.server.lights.Light;
+import com.android.server.lights.LightsManager;
 
 import android.app.ActivityManagerNative;
 import android.content.ContentResolver;
@@ -134,13 +136,10 @@ public final class BatteryService extends Binder {
 
     private boolean mSentLowBatteryBroadcast = false;
 
-    private BatteryListener mBatteryPropertiesListener;
-    private IBatteryPropertiesRegistrar mBatteryPropertiesRegistrar;
-
-    public BatteryService(Context context, LightsService lights) {
+    public BatteryService(Context context, LightsManager lightsManager) {
         mContext = context;
         mHandler = new Handler(true /*async*/);
-        mLed = new Led(context, lights);
+        mLed = new Led(context, lightsManager);
         mBatteryStats = BatteryStatsService.getService();
 
         mCriticalBatteryLevel = mContext.getResources().getInteger(
@@ -158,13 +157,11 @@ public final class BatteryService extends Binder {
                     "DEVPATH=/devices/virtual/switch/invalid_charger");
         }
 
-        mBatteryPropertiesListener = new BatteryListener();
-
         IBinder b = ServiceManager.getService("batterypropreg");
-        mBatteryPropertiesRegistrar = IBatteryPropertiesRegistrar.Stub.asInterface(b);
-
+        final IBatteryPropertiesRegistrar batteryPropertiesRegistrar =
+                IBatteryPropertiesRegistrar.Stub.asInterface(b);
         try {
-            mBatteryPropertiesRegistrar.registerListener(mBatteryPropertiesListener);
+            batteryPropertiesRegistrar.registerListener(new BatteryListener());
         } catch (RemoteException e) {
             // Should never happen.
         }
@@ -688,7 +685,7 @@ public final class BatteryService extends Binder {
     };
 
     private final class Led {
-        private final LightsService.Light mBatteryLight;
+        private final Light mBatteryLight;
 
         private final int mBatteryLowARGB;
         private final int mBatteryMediumARGB;
@@ -696,8 +693,8 @@ public final class BatteryService extends Binder {
         private final int mBatteryLedOn;
         private final int mBatteryLedOff;
 
-        public Led(Context context, LightsService lights) {
-            mBatteryLight = lights.getLight(LightsService.LIGHT_ID_BATTERY);
+        public Led(Context context, LightsManager lights) {
+            mBatteryLight = lights.getLight(LightsManager.LIGHT_ID_BATTERY);
 
             mBatteryLowARGB = context.getResources().getInteger(
                     com.android.internal.R.integer.config_notificationsBatteryLowARGB);
@@ -723,7 +720,7 @@ public final class BatteryService extends Binder {
                     mBatteryLight.setColor(mBatteryLowARGB);
                 } else {
                     // Flash red when battery is low and not charging
-                    mBatteryLight.setFlashing(mBatteryLowARGB, LightsService.LIGHT_FLASH_TIMED,
+                    mBatteryLight.setFlashing(mBatteryLowARGB, Light.LIGHT_FLASH_TIMED,
                             mBatteryLedOn, mBatteryLedOff);
                 }
             } else if (status == BatteryManager.BATTERY_STATUS_CHARGING
@@ -743,8 +740,14 @@ public final class BatteryService extends Binder {
     }
 
     private final class BatteryListener extends IBatteryPropertiesListener.Stub {
+        @Override
         public void batteryPropertiesChanged(BatteryProperties props) {
-            BatteryService.this.update(props);
+            final long identity = Binder.clearCallingIdentity();
+            try {
+                BatteryService.this.update(props);
+            } finally {
+                Binder.restoreCallingIdentity(identity);
+            }
        }
     }
 }