Run callbacks on ConnectivityService thread

Run MultinetworkPolicyTracker and DataConnectionStats callbacks on the
ConnectivityService handler thread.

Previously the callbacks would be using the SystemServer foreground
thread (Looper.myLooper()), or the broadcast thread for the
MultinetworkPolicyTracker BroadcastReceiver. This is error-prone, can
cause threading issues and makes it difficult to test the components.

Test: atest FrameworksNetTests
Change-Id: I189213dd363004abed294659165bf5430d153bba

core/java/android/net/util/MultinetworkPolicyTracker.java

@@ -64,7 +64,7 @@ public class MultinetworkPolicyTracker {
 
     private final Context mContext;
     private final Handler mHandler;
-    private final Runnable mReevaluateRunnable;
+    private final Runnable mAvoidBadWifiCallback;
     private final List<Uri> mSettingsUris;
     private final ContentResolver mResolver;
     private final SettingObserver mSettingObserver;
@@ -81,12 +81,7 @@ public class MultinetworkPolicyTracker {
     public MultinetworkPolicyTracker(Context ctx, Handler handler, Runnable avoidBadWifiCallback) {
         mContext = ctx;
         mHandler = handler;
-        mReevaluateRunnable = () -> {
-            if (updateAvoidBadWifi() && avoidBadWifiCallback != null) {
-                avoidBadWifiCallback.run();
-            }
-            updateMeteredMultipathPreference();
-        };
+        mAvoidBadWifiCallback = avoidBadWifiCallback;
         mSettingsUris = Arrays.asList(
             Settings.Global.getUriFor(NETWORK_AVOID_BAD_WIFI),
             Settings.Global.getUriFor(NETWORK_METERED_MULTIPATH_PREFERENCE));
@@ -95,15 +90,15 @@ public class MultinetworkPolicyTracker {
         mBroadcastReceiver = new BroadcastReceiver() {
             @Override
             public void onReceive(Context context, Intent intent) {
-                reevaluate();
+                reevaluateInternal();
             }
         };
 
-        TelephonyManager.from(ctx).listen(new PhoneStateListener() {
+        TelephonyManager.from(ctx).listen(new PhoneStateListener(handler.getLooper()) {
             @Override
             public void onActiveDataSubscriptionIdChanged(int subId) {
                 mActiveSubId = subId;
-                reevaluate();
+                reevaluateInternal();
             }
         }, PhoneStateListener.LISTEN_ACTIVE_DATA_SUBSCRIPTION_ID_CHANGE);
 
@@ -119,7 +114,7 @@ public class MultinetworkPolicyTracker {
         final IntentFilter intentFilter = new IntentFilter();
         intentFilter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
         mContext.registerReceiverAsUser(
-                mBroadcastReceiver, UserHandle.ALL, intentFilter, null, null);
+                mBroadcastReceiver, UserHandle.ALL, intentFilter, null, mHandler);
 
         reevaluate();
     }
@@ -164,7 +159,17 @@ public class MultinetworkPolicyTracker {
 
     @VisibleForTesting
     public void reevaluate() {
-        mHandler.post(mReevaluateRunnable);
+        mHandler.post(this::reevaluateInternal);
+    }
+
+    /**
+     * Reevaluate the settings. Must be called on the handler thread.
+     */
+    private void reevaluateInternal() {
+        if (updateAvoidBadWifi() && mAvoidBadWifiCallback != null) {
+            mAvoidBadWifiCallback.run();
+        }
+        updateMeteredMultipathPreference();
     }
 
     public boolean updateAvoidBadWifi() {

services/core/java/com/android/server/ConnectivityService.java

@@ -1101,7 +1101,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
         mSettingsObserver = new SettingsObserver(mContext, mHandler);
         registerSettingsCallbacks();
 
-        final DataConnectionStats dataConnectionStats = new DataConnectionStats(mContext);
+        final DataConnectionStats dataConnectionStats = new DataConnectionStats(mContext, mHandler);
         dataConnectionStats.startMonitoring();
 
         mKeepaliveTracker = new KeepaliveTracker(mContext, mHandler);