Merge "Reducing number of threads used in Recents."
diff --git a/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java b/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
index 3bd2fd1..03097ea 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
@@ -26,10 +26,10 @@
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Rect;
-import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.SystemClock;
 import android.os.UserHandle;
+import android.util.Log;
 import android.util.MutableBoolean;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -44,6 +44,7 @@
 import com.android.systemui.recents.events.component.RecentsVisibilityChangedEvent;
 import com.android.systemui.recents.events.component.ScreenPinningRequestEvent;
 import com.android.systemui.recents.misc.Console;
+import com.android.systemui.recents.misc.ForegroundThread;
 import com.android.systemui.recents.misc.SystemServicesProxy;
 import com.android.systemui.recents.model.RecentsTaskLoadPlan;
 import com.android.systemui.recents.model.RecentsTaskLoader;
@@ -66,6 +67,7 @@
         implements ActivityOptions.OnAnimationStartedListener {
 
     private final static String TAG = "RecentsImpl";
+    private final static boolean DEBUG = false;
 
     private final static int sMinToggleDelay = 350;
 
@@ -162,6 +164,9 @@
         Resources res = mContext.getResources();
         LayoutInflater inflater = LayoutInflater.from(mContext);
 
+        // Initialize the static foreground thread
+        ForegroundThread.get();
+
         // Register the task stack listener
         mTaskStackListener = new TaskStackListenerImpl(mHandler);
         SystemServicesProxy ssp = Recents.getSystemServices();
@@ -300,6 +305,8 @@
             loader.preloadTasks(sInstanceLoadPlan, topTaskHome.value);
             TaskStack stack = sInstanceLoadPlan.getTaskStack();
             if (stack.getTaskCount() > 0) {
+                // We try and draw the thumbnail transition bitmap in parallel before
+                // toggle/show recents is called
                 preCacheThumbnailTransitionBitmapAsync(topTask, stack, mDummyStackView);
             }
         }
@@ -458,7 +465,6 @@
      * Preloads the icon of a task.
      */
     private void preloadIcon(ActivityManager.RunningTaskInfo task) {
-
         // Ensure that we load the running task's icon
         RecentsTaskLoadPlan.Options launchOpts = new RecentsTaskLoadPlan.Options();
         launchOpts.runningTaskId = task.id;
@@ -483,18 +489,19 @@
         final Task toTask = new Task();
         final TaskViewTransform toTransform = getThumbnailTransitionTransform(stack, stackView,
                 topTask.id, toTask);
-        new AsyncTask<Void, Void, Bitmap>() {
+        ForegroundThread.getHandler().post(new Runnable() {
             @Override
-            protected Bitmap doInBackground(Void... params) {
-                return drawThumbnailTransitionBitmap(toTask, toTransform);
+            public void run() {
+                final Bitmap transitionBitmap = drawThumbnailTransitionBitmap(toTask, toTransform);
+                mHandler.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        mThumbnailTransitionBitmapCache = transitionBitmap;
+                        mThumbnailTransitionBitmapCacheKey = toTask;
+                    }
+                });
             }
-
-            @Override
-            protected void onPostExecute(Bitmap bitmap) {
-                mThumbnailTransitionBitmapCache = bitmap;
-                mThumbnailTransitionBitmapCacheKey = toTask;
-            }
-        }.execute();
+        });
     }
 
     /**
diff --git a/packages/SystemUI/src/com/android/systemui/recents/misc/ForegroundThread.java b/packages/SystemUI/src/com/android/systemui/recents/misc/ForegroundThread.java
new file mode 100644
index 0000000..8dc2983
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/recents/misc/ForegroundThread.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2015 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.systemui.recents.misc;
+
+import android.os.Handler;
+import android.os.HandlerThread;
+
+/**
+ * Similar to {@link com.android.internal.os.BackgroundThread}, this is a shared singleton
+ * foreground thread for each process.
+ */
+public final class ForegroundThread extends HandlerThread {
+    private static ForegroundThread sInstance;
+    private static Handler sHandler;
+
+    private ForegroundThread() {
+        super("recents.fg", android.os.Process.THREAD_PRIORITY_BACKGROUND);
+    }
+
+    private static void ensureThreadLocked() {
+        if (sInstance == null) {
+            sInstance = new ForegroundThread();
+            sInstance.start();
+            sHandler = new Handler(sInstance.getLooper());
+        }
+    }
+
+    public static ForegroundThread get() {
+        synchronized (ForegroundThread.class) {
+            ensureThreadLocked();
+            return sInstance;
+        }
+    }
+
+    public static Handler getHandler() {
+        synchronized (ForegroundThread.class) {
+            ensureThreadLocked();
+            return sHandler;
+        }
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java b/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
index dab2c65..a51e475 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
@@ -46,8 +46,6 @@
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
-import android.os.Handler;
-import android.os.HandlerThread;
 import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
 import android.os.SystemProperties;
@@ -61,6 +59,7 @@
 import android.view.WindowManager;
 import android.view.accessibility.AccessibilityManager;
 import com.android.internal.app.AssistUtils;
+import com.android.internal.os.BackgroundThread;
 import com.android.systemui.Prefs;
 import com.android.systemui.R;
 import com.android.systemui.recents.Constants;
@@ -83,12 +82,8 @@
     final static String TAG = "SystemServicesProxy";
 
     final static BitmapFactory.Options sBitmapOptions;
-    final static HandlerThread sBgThread;
 
     static {
-        sBgThread = new HandlerThread("Recents-SystemServicesProxy",
-                android.os.Process.THREAD_PRIORITY_BACKGROUND);
-        sBgThread.start();
         sBitmapOptions = new BitmapFactory.Options();
         sBitmapOptions.inMutable = true;
     }
@@ -106,8 +101,6 @@
     String mRecentsPackage;
     ComponentName mAssistComponent;
 
-    Handler mBgThreadHandler;
-
     Bitmap mDummyIcon;
     int mDummyThumbnailWidth;
     int mDummyThumbnailHeight;
@@ -127,7 +120,6 @@
         mUm = UserManager.get(context);
         mDisplay = mWm.getDefaultDisplay();
         mRecentsPackage = context.getPackageName();
-        mBgThreadHandler = new Handler(sBgThread.getLooper());
 
         // Get the dummy thumbnail width/heights
         Resources res = context.getResources();
@@ -418,7 +410,7 @@
         if (Constants.DebugFlags.App.EnableSystemServicesProxy) return;
 
         // Remove the task.
-        mBgThreadHandler.post(new Runnable() {
+        BackgroundThread.getHandler().post(new Runnable() {
             @Override
             public void run() {
                 mAm.removeTask(taskId);
diff --git a/packages/SystemUI/src/com/android/systemui/recents/model/RecentsPackageMonitor.java b/packages/SystemUI/src/com/android/systemui/recents/model/RecentsPackageMonitor.java
index f0793b1..d9057b8 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/model/RecentsPackageMonitor.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/model/RecentsPackageMonitor.java
@@ -19,6 +19,7 @@
 import android.content.Context;
 import android.os.UserHandle;
 import com.android.internal.content.PackageMonitor;
+import com.android.internal.os.BackgroundThread;
 import com.android.systemui.recents.events.EventBus;
 import com.android.systemui.recents.events.activity.PackagesChangedEvent;
 
@@ -32,9 +33,9 @@
     public void register(Context context) {
         try {
             // We register for events from all users, but will cross-reference them with
-            // packages for the current user and any profiles they have.  Passing null into the
-            // call also ensures that events are handled in a background thread.
-            register(context, null, UserHandle.ALL, true);
+            // packages for the current user and any profiles they have.  Ensure that events are
+            // handled in a background thread.
+            register(context, BackgroundThread.get().getLooper(), UserHandle.ALL, true);
         } catch (IllegalStateException e) {
             e.printStackTrace();
         }