Start combining threads in system process.

This introduces four generic thread that services can
use in the system process:

- Background: part of the framework for all processes, for
work that is purely background (no timing constraint).
- UI: for time-critical display of UI.
- Foreground: normal foreground work.
- IO: performing IO operations.

I went through and moved services into these threads in the
places I felt relatively comfortable about understanding what
they are doing.  There are still a bunch more we need to look
at -- lots of networking stuff left, 3 or so different native
daemon connectors which I didn't know how much would block,
audio stuff, etc.

Also updated Watchdog to be aware of and check these new
threads, with a new API for other threads to also participate
in this checking.

Change-Id: Ie2f11061cebde5f018d7383b3a910fbbd11d5e11

1 files changed, 2 insertions, 4 deletions

diff --git a/services/java/com/android/server/AppWidgetService.java b/services/java/com/android/server/AppWidgetService.java
index d5715a527f56..5b76f3954d97 100644
--- a/services/java/com/android/server/AppWidgetService.java
+++ b/services/java/com/android/server/AppWidgetService.java
@@ -27,7 +27,6 @@ import android.content.pm.PackageManager;
 import android.os.Binder;
 import android.os.Bundle;
 import android.os.Handler;
-import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.UserHandle;
@@ -37,6 +36,7 @@ import android.widget.RemoteViews;
 
 import com.android.internal.appwidget.IAppWidgetHost;
 import com.android.internal.appwidget.IAppWidgetService;
+import com.android.internal.os.BackgroundThread;
 import com.android.internal.util.IndentingPrintWriter;
 
 import java.io.FileDescriptor;
@@ -63,9 +63,7 @@ class AppWidgetService extends IAppWidgetService.Stub
     AppWidgetService(Context context) {
         mContext = context;
 
-        HandlerThread handlerThread = new HandlerThread("AppWidgetService -- Save state");
-        handlerThread.start();
-        mSaveStateHandler = new Handler(handlerThread.getLooper());
+        mSaveStateHandler = BackgroundThread.getHandler();
 
         mAppWidgetServices = new SparseArray<AppWidgetServiceImpl>(5);
         AppWidgetServiceImpl primary = new AppWidgetServiceImpl(context, 0, mSaveStateHandler);