Merge "Add test for BinderCacheManager"

/*

 * Copyright (C) 2020 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package android.telephony;

import static org.junit.Assert.assertEquals;

import static org.junit.Assert.assertNotEquals;

import static org.junit.Assert.assertNotNull;

import static org.junit.Assert.assertNull;

import static org.mockito.ArgumentMatchers.anyInt;

import static org.mockito.ArgumentMatchers.eq;

import static org.mockito.Mockito.verify;

import static org.mockito.Mockito.when;

import android.os.IBinder;

import android.os.IInterface;

import android.test.suitebuilder.annotation.SmallTest;

import androidx.test.runner.AndroidJUnit4;

import org.junit.Before;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.mockito.ArgumentCaptor;

import org.mockito.Mock;

import org.mockito.MockitoAnnotations;

import java.util.concurrent.CountDownLatch;

@RunWith(AndroidJUnit4.class)

public class BinderCacheManagerTest {

    @Mock IInterface mInterface;

    @Mock IBinder mIBinder;

    private BinderCacheManager<IInterface> mBinderCache;

    @Before

    public void setUp() throws Exception {

        MockitoAnnotations.initMocks(this);

        when(mInterface.asBinder()).thenReturn(mIBinder);

        mBinderCache = new BinderCacheManager<>(() -> mInterface);

    }

    @Test

    @SmallTest

    public void testGetConnection() {

        when(mIBinder.isBinderAlive()).thenReturn(true);

        assertEquals(mInterface, mBinderCache.getBinder());

        when(mIBinder.isBinderAlive()).thenReturn(false);

        assertNull(mBinderCache.getBinder());

    }

    @Test

    @SmallTest

    public void testAddListenerAndDie() throws Exception {

        IBinder.DeathRecipient recipient = populateCacheCaptureDeathRecipent();

        CountDownLatch l = new CountDownLatch(1);

        assertEquals(mInterface, mBinderCache.listenOnBinder(l, l::countDown));

        when(mIBinder.isBinderAlive()).thenReturn(false);

        recipient.binderDied();

        assertEquals(0, l.getCount());

        assertNull(mBinderCache.getBinder());

        // Listeners should not be abailable wile remote process is not available.

        assertNull(mBinderCache.listenOnBinder(l, l::countDown));

        assertNull(mBinderCache.removeRunnable(l));

        verify(mIBinder).unlinkToDeath(eq(recipient), anyInt());

    }

    @Test

    @SmallTest

    public void testListenerNotCalledAfterRemoved() throws Exception {

        IBinder.DeathRecipient recipient = populateCacheCaptureDeathRecipent();

        CountDownLatch l = new CountDownLatch(1);

        assertEquals(mInterface, mBinderCache.listenOnBinder(l, l::countDown));

        assertEquals(mInterface, mBinderCache.removeRunnable(l));

        when(mIBinder.isBinderAlive()).thenReturn(false);

        recipient.binderDied();

        // Callback should never have been called because the runnable was removed before it died.

        assertNotEquals(0, l.getCount());

    }

    @Test

    @SmallTest

    public void testAddListenerAlreadyDead() throws Exception {

        IBinder.DeathRecipient recipient = populateCacheCaptureDeathRecipent();

        when(mIBinder.isBinderAlive()).thenReturn(false);

        recipient.binderDied();

        CountDownLatch l = new CountDownLatch(1);

        assertNull(mBinderCache.listenOnBinder(l, l::countDown));

        assertNull(mBinderCache.removeRunnable(l));

        // Callback shouldn't be called if it was never added in the first place.

        assertNotEquals(0, l.getCount());

    }

    /**

     * Populate the cache with mInterface & capture the associated DeathRecipient

     */

    private IBinder.DeathRecipient populateCacheCaptureDeathRecipent() throws Exception {

        when(mIBinder.isBinderAlive()).thenReturn(true);

        // Call getBinder() to populate cache the first time.

        assertEquals(mInterface, mBinderCache.getBinder());

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

                IBinder.DeathRecipient.class);

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

        IBinder.DeathRecipient recipient = captor.getValue();

        assertNotNull(recipient);

        return recipient;

    }

}