Add a test for mobile data always on.

Bug: 23113288
Change-Id: Ia8649061a797367d135bb5576600a7cdc85a822e

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

@@ -786,6 +786,17 @@ public class ConnectivityService extends IConnectivityManager.Stub
         return new NetworkRequest(netCap, TYPE_NONE, nextNetworkRequestId());
     }
 
+    // Used only for testing.
+    // TODO: Delete this and either:
+    // 1. Give Fake SettingsProvider the ability to send settings change notifications (requires
+    //    changing ContentResolver to make registerContentObserver non-final).
+    // 2. Give FakeSettingsProvider an alternative notification mechanism and have the test use it
+    //    by subclassing SettingsObserver.
+    @VisibleForTesting
+    void updateMobileDataAlwaysOn() {
+        mHandler.sendEmptyMessage(EVENT_CONFIGURE_MOBILE_DATA_ALWAYS_ON);
+    }
+
     private void handleMobileDataAlwaysOn() {
         final boolean enable = (Settings.Global.getInt(
                 mContext.getContentResolver(), Settings.Global.MOBILE_DATA_ALWAYS_ON, 0) == 1);

services/tests/servicestests/src/com/android/server/ConnectivityServiceTest.java

@@ -1490,6 +1490,73 @@ public class ConnectivityServiceTest extends AndroidTestCase {
         defaultNetworkCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
     }
 
+    @SmallTest
+    public void testMobileDataAlwaysOn() throws Exception {
+        final TestNetworkCallback cellNetworkCallback = new TestNetworkCallback();
+        final NetworkRequest cellRequest = new NetworkRequest.Builder()
+                .addTransportType(TRANSPORT_CELLULAR).build();
+        mCm.registerNetworkCallback(cellRequest, cellNetworkCallback);
+
+        final HandlerThread handlerThread = new HandlerThread("MobileDataAlwaysOnFactory");
+        handlerThread.start();
+        NetworkCapabilities filter = new NetworkCapabilities()
+                .addTransportType(TRANSPORT_CELLULAR)
+                .addCapability(NET_CAPABILITY_INTERNET);
+        final MockNetworkFactory testFactory = new MockNetworkFactory(handlerThread.getLooper(),
+                mServiceContext, "testFactory", filter);
+        testFactory.setScoreFilter(40);
+
+        // Register the factory and expect it to start looking for a network.
+        testFactory.expectAddRequests(1);
+        testFactory.register();
+        testFactory.waitForNetworkRequests(1);
+        assertTrue(testFactory.getMyStartRequested());
+
+        // Bring up wifi. The factory stops looking for a network.
+        mWiFiNetworkAgent = new MockNetworkAgent(TRANSPORT_WIFI);
+        testFactory.expectAddRequests(2);  // Because the default request changes score twice.
+        mWiFiNetworkAgent.connect(true);
+        testFactory.waitForNetworkRequests(1);
+        assertFalse(testFactory.getMyStartRequested());
+
+        ContentResolver cr = mServiceContext.getContentResolver();
+
+        // Turn on mobile data always on. The factory starts looking again.
+        testFactory.expectAddRequests(1);
+        Settings.Global.putInt(cr, Settings.Global.MOBILE_DATA_ALWAYS_ON, 1);
+        mService.updateMobileDataAlwaysOn();
+        testFactory.waitForNetworkRequests(2);
+        assertTrue(testFactory.getMyStartRequested());
+
+        // Bring up cell data and check that the factory stops looking.
+        assertEquals(1, mCm.getAllNetworks().length);
+        mCellNetworkAgent = new MockNetworkAgent(TRANSPORT_CELLULAR);
+        testFactory.expectAddRequests(2);  // Because the cell request changes score twice.
+        mCellNetworkAgent.connect(true);
+        cellNetworkCallback.expectCallback(CallbackState.AVAILABLE);
+        testFactory.waitForNetworkRequests(2);
+        assertFalse(testFactory.getMyStartRequested());  // Because the cell network outscores us.
+
+        // Check that cell data stays up.
+        mService.waitForIdle();
+        verifyActiveNetwork(TRANSPORT_WIFI);
+        assertEquals(2, mCm.getAllNetworks().length);
+
+        // Turn off mobile data always on and expect the request to disappear...
+        testFactory.expectRemoveRequests(1);
+        Settings.Global.putInt(cr, Settings.Global.MOBILE_DATA_ALWAYS_ON, 0);
+        mService.updateMobileDataAlwaysOn();
+        testFactory.waitForNetworkRequests(1);
+
+        // ...  and cell data to be torn down.
+        cellNetworkCallback.expectCallback(CallbackState.LOST);
+        assertEquals(1, mCm.getAllNetworks().length);
+
+        testFactory.unregister();
+        mCm.unregisterNetworkCallback(cellNetworkCallback);
+        handlerThread.quit();
+    }
+
     private static class TestKeepaliveCallback extends PacketKeepaliveCallback {
 
         public static enum CallbackType { ON_STARTED, ON_STOPPED, ON_ERROR };