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, 5 deletions

diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index 26753094a978..b162c6bb6354 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -63,6 +63,7 @@ import android.util.Slog;
 import com.android.internal.content.PackageMonitor;
 import com.android.internal.location.ProviderProperties;
 import com.android.internal.location.ProviderRequest;
+import com.android.internal.os.BackgroundThread;
 import com.android.server.location.GeocoderProxy;
 import com.android.server.location.GeofenceProxy;
 import com.android.server.location.GeofenceManager;
@@ -93,7 +94,6 @@ public class LocationManagerService extends ILocationManager.Stub {
     public static final boolean D = Log.isLoggable(TAG, Log.DEBUG);
 
     private static final String WAKELOCK_KEY = TAG;
-    private static final String THREAD_NAME = TAG;
 
     // Location resolution level: no location data whatsoever
     private static final int RESOLUTION_LEVEL_NONE = 0;
@@ -143,7 +143,6 @@ public class LocationManagerService extends ILocationManager.Stub {
     private LocationWorkerHandler mLocationHandler;
     private PassiveProvider mPassiveProvider;  // track passive provider for special cases
     private LocationBlacklist mBlacklist;
-    private HandlerThread mHandlerThread;
 
     // --- fields below are protected by mWakeLock ---
     private int mPendingBroadcasts;
@@ -216,9 +215,7 @@ public class LocationManagerService extends ILocationManager.Stub {
             mWakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKELOCK_KEY);
 
             // prepare worker thread
-            mHandlerThread = new HandlerThread(THREAD_NAME, Process.THREAD_PRIORITY_BACKGROUND);
-            mHandlerThread.start();
-            mLocationHandler = new LocationWorkerHandler(mHandlerThread.getLooper());
+            mLocationHandler = new LocationWorkerHandler(BackgroundThread.get().getLooper());
 
             // prepare mLocationHandler's dependents
             mLocationFudger = new LocationFudger(mContext, mLocationHandler);