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Commit ff706835 authored by Phil Weaver's avatar Phil Weaver
Browse files

Handle UiAutomation dying before being connected 

There was an opportunity for the UiAutomation's binder
to die before it was connected, which caused an
NPE when it tried to connect.

I also moved the message handling to a different handler
to make it easier to test.

Bug: 65474486
Test: UiAutomation CTS passes. I also added a unit test
that failed in the same way as the bug. That test now
passes.

Change-Id: I31036ace114b21fed64227b62212b95267039d9e
parent acef92cd

services/accessibility/java/com/android/server/accessibility/UiAutomationManager.java

+20 −7
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ class UiAutomationManager { 
    private int mUiAutomationFlags;



    private IBinder mUiAutomationServiceOwner;

    private final DeathRecipient mUiAutomationSerivceOwnerDeathRecipient =

    private final DeathRecipient mUiAutomationServiceOwnerDeathRecipient =

            new DeathRecipient() {

                @Override

                public void binderDied() {
@@ -85,7 +85,7 @@ class UiAutomationManager { 
        }



        try {

            owner.linkToDeath(mUiAutomationSerivceOwnerDeathRecipient, 0);

            owner.linkToDeath(mUiAutomationServiceOwnerDeathRecipient, 0);

        } catch (RemoteException re) {

            Slog.e(LOG_TAG, "Couldn't register for the death of a UiTestAutomationService!", re);

            return;
@@ -165,12 +165,14 @@ class UiAutomationManager { 
        mUiAutomationService = null;

        mUiAutomationFlags = 0;

        if (mUiAutomationServiceOwner != null) {

            mUiAutomationServiceOwner.unlinkToDeath(mUiAutomationSerivceOwnerDeathRecipient, 0);

            mUiAutomationServiceOwner.unlinkToDeath(mUiAutomationServiceOwnerDeathRecipient, 0);

            mUiAutomationServiceOwner = null;

        }

    }



    private class UiAutomationService extends AccessibilityClientConnection {

        private final Handler mMainHandler;



        UiAutomationService(Context context, AccessibilityServiceInfo accessibilityServiceInfo,

                int id, Handler mainHandler, Object lock,

                AccessibilityManagerService.SecurityPolicy securityPolicy,
@@ -178,15 +180,26 @@ class UiAutomationManager { 
                GlobalActionPerformer globalActionPerfomer) {

            super(context, COMPONENT_NAME, accessibilityServiceInfo, id, mainHandler, lock,

                    securityPolicy, systemSupport, windowManagerInternal, globalActionPerfomer);

            mMainHandler = mainHandler;

        }



        void connectServiceUnknownThread() {

            // This needs to be done on the main thread

            mEventDispatchHandler.post(() -> {

            mMainHandler.post(() -> {

                try {

                    mService = mServiceInterface.asBinder();

                    mService.linkToDeath(this, 0);

                    mServiceInterface.init(this, mId, mOverlayWindowToken);

                    final IAccessibilityServiceClient serviceInterface;

                    final IBinder service;

                    synchronized (mLock) {

                        serviceInterface = mServiceInterface;

                        mService = (serviceInterface == null) ? null : mServiceInterface.asBinder();

                        service = mService;

                    }

                    // If the serviceInterface is null, the UiAutomation has been shut down on

                    // another thread.

                    if (serviceInterface != null) {

                        service.linkToDeath(this, 0);

                        serviceInterface.init(this, mId, mOverlayWindowToken);

                    }

                } catch (RemoteException re) {

                    Slog.w(LOG_TAG, "Error initialized connection", re);

                    destroyUiAutomationService();

services/tests/servicestests/src/com/android/server/accessibility/MessageCapturingHandler.java

+11 −2
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 


package com.android.server.accessibility;



import android.app.Notification;

import android.os.Handler;

import android.os.Message;

import android.util.Pair;
@@ -49,7 +50,7 @@ public class MessageCapturingHandler extends Handler { 
    public void sendOneMessage() {

        Message message = timedMessages.remove(0).first;

        removeMessages(message.what, message.obj);

        mCallback.handleMessage(message);

        dispatchMessage(message);

        removeStaleMessages();

    }
@@ -62,7 +63,7 @@ public class MessageCapturingHandler extends Handler { 
    public void sendLastMessage() {

        Message message = timedMessages.remove(timedMessages.size() - 1).first;

        removeMessages(message.what, message.obj);

        mCallback.handleMessage(message);

        dispatchMessage(message);

        removeStaleMessages();

    }
@@ -79,4 +80,12 @@ public class MessageCapturingHandler extends Handler { 
            }

        }

    }



    public void dispatchMessage(Message m) {

        if (mCallback != null) {

            mCallback.handleMessage(m);

            return;

        }

        super.dispatchMessage(m);

    }

}

services/tests/servicestests/src/com/android/server/accessibility/UiAutomationManagerTest.java

+18 −3
Original line number Diff line number Diff line
@@ -19,7 +19,9 @@ package com.android.server.accessibility; 
import static org.junit.Assert.assertEquals;

import static org.junit.Assert.assertFalse;

import static org.junit.Assert.assertTrue;

import static org.mockito.ArgumentMatchers.anyInt;

import static org.mockito.Mockito.mock;

import static org.mockito.Mockito.verify;

import static org.mockito.Mockito.when;



import android.accessibilityservice.AccessibilityServiceInfo;
@@ -29,7 +31,6 @@ import android.content.Context; 
import android.content.pm.ApplicationInfo;

import android.content.pm.ResolveInfo;

import android.content.pm.ServiceInfo;

import android.os.Handler;

import android.os.IBinder;

import android.os.Looper;

import android.view.WindowManagerInternal;
@@ -38,6 +39,7 @@ import android.view.accessibility.AccessibilityEvent; 
import org.junit.Before;

import org.junit.BeforeClass;

import org.junit.Test;

import org.mockito.ArgumentCaptor;

import org.mockito.Mock;

import org.mockito.MockitoAnnotations;
@@ -49,6 +51,8 @@ public class UiAutomationManagerTest { 


    final UiAutomationManager mUiAutomationManager = new UiAutomationManager();



    MessageCapturingHandler mMessageCapturingHandler;



    @Mock AccessibilityManagerService.UserState mMockUserState;

    @Mock Context mMockContext;

    @Mock AccessibilityServiceInfo mMockServiceInfo;
@@ -68,7 +72,6 @@ public class UiAutomationManagerTest { 
        }

    }





    @Before

    public void setup() {

        MockitoAnnotations.initMocks(this);
@@ -80,6 +83,8 @@ public class UiAutomationManagerTest { 
        mMockResolveInfo.serviceInfo.applicationInfo = mock(ApplicationInfo.class);



        when(mMockAccessibilityServiceClient.asBinder()).thenReturn(mMockServiceAsBinder);



        mMessageCapturingHandler = new MessageCapturingHandler(null);

    }



    @Test
@@ -146,10 +151,20 @@ public class UiAutomationManagerTest { 
        assertEquals(0, mUiAutomationManager.getRequestedEventMaskLocked());

    }



    @Test

    public void uiAutomationBinderDiesBeforeConnecting_shouldNotCrash() throws Exception {

        register(0);

        ArgumentCaptor<IBinder.DeathRecipient> captor = ArgumentCaptor.forClass(

                IBinder.DeathRecipient.class);

        verify(mMockOwner).linkToDeath(captor.capture(), anyInt());

        captor.getValue().binderDied();

        mMessageCapturingHandler.sendAllMessages();

    }



    private void register(int flags) {

        mUiAutomationManager.registerUiTestAutomationServiceLocked(mMockOwner,

                mMockAccessibilityServiceClient, mMockContext, mMockServiceInfo, SERVICE_ID,

                new Handler(), new Object(), mMockSecurityPolicy, mMockSystemSupport,

                mMessageCapturingHandler, new Object(), mMockSecurityPolicy, mMockSystemSupport,

                mMockWindowManagerInternal, mMockGlobalActionPerformer, flags);

    }