Register callback and receiver after tethering is created

Tethering service is created after boot complete which means most of
the services are ready before tethering. Once tethering register the
callback, callback event may come-in immediately. Make sure all of
tethering related object is created, then register the callback,
receiver, or listener.

Bug: 149965121
Test: atest TetheringTests
      manual on/off tethering

Change-Id: Ifdc427341db7d1313ad4b61207a96ab379d100aa
Merged-In: I3941a186770679e7b476073d774e2310e25e44c6
(cherry picked from commit 285be1ee938ddc9728ccc3e951ed0ed1b2fa7117)

3 files changed, 18 insertions, 15 deletions

diff --git a/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java b/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
index c84892d675f9..4b2c9215f7b7 100644
--- a/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
+++ b/packages/Tethering/src/com/android/server/connectivity/tethering/Tethering.java
@@ -307,28 +307,22 @@ public class Tethering {
                 userManager, this, mNotificationUpdater);
         mExecutor = new TetheringThreadExecutor(mHandler);
         mActiveDataSubIdListener = new ActiveDataSubIdListener(mExecutor);
+        mNetdCallback = new NetdCallback();
 
         // Load tethering configuration.
         updateConfiguration();
-        // NetdCallback should be registered after updateConfiguration() to ensure
-        // TetheringConfiguration is created.
-        mNetdCallback = new NetdCallback();
+    }
+
+    /**
+     * Start to register callbacks.
+     * Call this function when tethering is ready to handle callback events.
+     */
+    public void startStateMachineUpdaters() {
         try {
             mNetd.registerUnsolicitedEventListener(mNetdCallback);
         } catch (RemoteException e) {
             mLog.e("Unable to register netd UnsolicitedEventListener");
         }
-
-        startStateMachineUpdaters(mHandler);
-        startTrackDefaultNetwork();
-
-        final WifiManager wifiManager = getWifiManager();
-        if (wifiManager != null) {
-            wifiManager.registerSoftApCallback(mExecutor, new TetheringSoftApCallback());
-        }
-    }
-
-    private void startStateMachineUpdaters(Handler handler) {
         mCarrierConfigChange.startListening();
         mContext.getSystemService(TelephonyManager.class).listen(mActiveDataSubIdListener,
                 PhoneStateListener.LISTEN_ACTIVE_DATA_SUBSCRIPTION_ID_CHANGE);
@@ -341,7 +335,14 @@ public class Tethering {
         filter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
         filter.addAction(UserManager.ACTION_USER_RESTRICTIONS_CHANGED);
         filter.addAction(ACTION_RESTRICT_BACKGROUND_CHANGED);
-        mContext.registerReceiver(mStateReceiver, filter, null, handler);
+        mContext.registerReceiver(mStateReceiver, filter, null, mHandler);
+
+        final WifiManager wifiManager = getWifiManager();
+        if (wifiManager != null) {
+            wifiManager.registerSoftApCallback(mExecutor, new TetheringSoftApCallback());
+        }
+
+        startTrackDefaultNetwork();
     }
 
     private class TetheringThreadExecutor implements Executor {
diff --git a/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java b/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java
index c5329d8d3316..c30be25dbd22 100644
--- a/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java
+++ b/packages/Tethering/src/com/android/server/connectivity/tethering/TetheringService.java
@@ -80,6 +80,7 @@ public class TetheringService extends Service {
         mContext = mDeps.getContext();
         mUserManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
         mTethering = makeTethering(mDeps);
+        mTethering.startStateMachineUpdaters();
     }
 
     /**
diff --git a/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java b/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
index 5ead1106d75a..a59c6fd9e193 100644
--- a/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
+++ b/packages/Tethering/tests/unit/src/com/android/server/connectivity/tethering/TetheringTest.java
@@ -484,6 +484,7 @@ public class TetheringTest {
         mServiceContext.registerReceiver(mBroadcastReceiver,
                 new IntentFilter(ACTION_TETHER_STATE_CHANGED));
         mTethering = makeTethering();
+        mTethering.startStateMachineUpdaters();
         verify(mStatsManager, times(1)).registerNetworkStatsProvider(anyString(), any());
         verify(mNetd).registerUnsolicitedEventListener(any());
         final ArgumentCaptor<PhoneStateListener> phoneListenerCaptor =