Add ServiceHolder for AudioPolicy (d2bccdab) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/audio/AudioService.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -1000,7 +1000,7 @@ public class AudioService extends IAudioService.Stub
		SystemServerAdapter.getDefaultAdapter(context),
		SettingsAdapter.getDefaultAdapter(),
		new AudioVolumeGroupHelper(),
		new DefaultAudioPolicyFacade(),
		new DefaultAudioPolicyFacade(r -> r.run()),
		null);

		}

services/core/java/com/android/server/audio/DefaultAudioPolicyFacade.java

+20 −77

Original line number	Diff line number	Diff line
		@@ -16,100 +16,43 @@

		package com.android.server.audio;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.media.IAudioPolicyService;
		import android.media.permission.ClearCallingIdentityContext;
		import android.media.permission.SafeCloseable;
		import android.os.IBinder;
		import android.os.RemoteException;
		import android.os.ServiceManager;
		import android.util.Log;

		import com.android.internal.annotations.GuardedBy;
		import java.util.concurrent.Executor;
		import java.util.function.Function;

		/**
		* Default implementation of a facade to IAudioPolicyManager which fulfills AudioService
		* dependencies. This forwards calls as-is to IAudioPolicyManager.
		* Public methods throw IllegalStateException if AudioPolicy is not initialized/available
		* Default implementation of a facade to IAudioPolicyService which fulfills AudioService
		* dependencies. This forwards calls as-is to IAudioPolicyService.
		*/
		public class DefaultAudioPolicyFacade implements AudioPolicyFacade, IBinder.DeathRecipient {
		public class DefaultAudioPolicyFacade implements AudioPolicyFacade {

		private static final String TAG = "DefaultAudioPolicyFacade";
		private static final String AUDIO_POLICY_SERVICE_NAME = "media.audio_policy";

		private final Object mServiceLock = new Object();
		@GuardedBy("mServiceLock")
		private IAudioPolicyService mAudioPolicy;
		private final ServiceHolder<IAudioPolicyService> mServiceHolder;

		public DefaultAudioPolicyFacade() {
		try {
		getAudioPolicyOrInit();
		} catch (IllegalStateException e) {
		// Log and suppress this exception, we may be able to connect later
		Log.e(TAG, "Failed to initialize APM connection", e);
		}
		/**
		* @param e - Executor for service start tasks
		*/
		public DefaultAudioPolicyFacade(Executor e) {
		mServiceHolder =
		new ServiceHolder(
		AUDIO_POLICY_SERVICE_NAME,
		(Function<IBinder, IAudioPolicyService>)
		IAudioPolicyService.Stub::asInterface,
		e);
		}

		@Override
		public boolean isHotwordStreamSupported(boolean lookbackAudio) {
		IAudioPolicyService ap = getAudioPolicyOrInit();
		try (SafeCloseable ignored = ClearCallingIdentityContext.create()) {
		return ap.isHotwordStreamSupported(lookbackAudio);
		} catch (RemoteException e) {
		resetServiceConnection(ap.asBinder());
		throw new IllegalStateException(e);
		}
		}

		@Override
		public void binderDied() {
		Log.wtf(TAG, "Unexpected binderDied without IBinder object");
		}

		@Override
		public void binderDied(@NonNull IBinder who) {
		resetServiceConnection(who);
		}

		private void resetServiceConnection(@Nullable IBinder deadAudioPolicy) {
		synchronized (mServiceLock) {
		if (mAudioPolicy != null && mAudioPolicy.asBinder().equals(deadAudioPolicy)) {
		mAudioPolicy.asBinder().unlinkToDeath(this, 0);
		mAudioPolicy = null;
		}
		}
		}

		private @Nullable IAudioPolicyService getAudioPolicy() {
		synchronized (mServiceLock) {
		return mAudioPolicy;
		}
		}

		/*
		* Does not block.
		* @throws IllegalStateException for any failed connection
		*/
		private @NonNull IAudioPolicyService getAudioPolicyOrInit() {
		synchronized (mServiceLock) {
		if (mAudioPolicy != null) {
		return mAudioPolicy;
		}
		// Do not block while attempting to connect to APM. Defer to caller.
		IAudioPolicyService ap = IAudioPolicyService.Stub.asInterface(
		ServiceManager.checkService(AUDIO_POLICY_SERVICE_NAME));
		if (ap == null) {
		throw new IllegalStateException(TAG + ": Unable to connect to AudioPolicy");
		}
		IAudioPolicyService ap = mServiceHolder.waitForService();
		try {
		ap.asBinder().linkToDeath(this, 0);
		return ap.isHotwordStreamSupported(lookbackAudio);
		} catch (RemoteException e) {
		throw new IllegalStateException(
		TAG + ": Unable to link deathListener to AudioPolicy", e);
		}
		mAudioPolicy = ap;
		return mAudioPolicy;
		mServiceHolder.attemptClear(ap.asBinder());
		throw new IllegalStateException();
		}
		}
		}

services/core/java/com/android/server/audio/ServiceHolder.java

0 → 100644

+219 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2024 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 com.android.server.audio;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.os.IBinder;
		import android.os.IInterface;
		import android.os.IServiceCallback;
		import android.os.RemoteException;
		import android.os.ServiceManager;
		import android.util.Log;

		import java.util.Objects;
		import java.util.Set;
		import java.util.concurrent.ConcurrentHashMap;
		import java.util.concurrent.Executor;
		import java.util.concurrent.atomic.AtomicReference;
		import java.util.function.Consumer;
		import java.util.function.Function;

		/**
		* Manages a remote service which can start and stop. Allows clients to add tasks to run when the
		* remote service starts or dies.
		*
		* <p>Example usage should look something like:
		*
		* <pre>
		* var service = mServiceHolder.checkService();
		* if (service == null) handleFailure();
		* try {
		* service.foo();
		* } catch (RemoteException e) {
		* mServiceHolder.attemptClear(service.asBinder());
		* handleFailure();
		* }
		* </pre>
		*/
		public class ServiceHolder<I extends IInterface> implements IBinder.DeathRecipient {

		private final String mTag;
		private final String mServiceName;
		private final Function<? super IBinder, ? extends I> mCastFunction;
		private final Executor mExecutor;
		private final ServiceProviderFacade mServiceProvider;

		private final AtomicReference<I> mService = new AtomicReference();
		private final Set<Consumer<I>> mOnStartTasks = ConcurrentHashMap.newKeySet();
		private final Set<Consumer<I>> mOnDeathTasks = ConcurrentHashMap.newKeySet();

		private final IServiceCallback mServiceListener =
		new IServiceCallback.Stub() {
		@Override
		public void onRegistration(String name, IBinder binder) {
		onServiceInited(binder);
		}
		};

		// For test purposes
		public static interface ServiceProviderFacade {
		public void registerForNotifications(String name, IServiceCallback listener);

		public IBinder checkService(String name);

		public IBinder waitForService(String name);
		}

		public ServiceHolder(
		@NonNull String serviceName,
		@NonNull Function<? super IBinder, ? extends I> castFunction,
		@NonNull Executor executor) {
		this(
		serviceName,
		castFunction,
		executor,
		new ServiceProviderFacade() {
		@Override
		public void registerForNotifications(String name, IServiceCallback listener) {
		try {
		ServiceManager.registerForNotifications(name, listener);
		} catch (RemoteException e) {
		throw new IllegalStateException("ServiceManager died!!", e);
		}
		}

		@Override
		public IBinder checkService(String name) {
		return ServiceManager.checkService(name);
		}

		@Override
		public IBinder waitForService(String name) {
		return ServiceManager.waitForService(name);
		}
		});
		}

		public ServiceHolder(
		@NonNull String serviceName,
		@NonNull Function<? super IBinder, ? extends I> castFunction,
		@NonNull Executor executor,
		@NonNull ServiceProviderFacade provider) {
		mServiceName = Objects.requireNonNull(serviceName);
		mCastFunction = Objects.requireNonNull(castFunction);
		mExecutor = Objects.requireNonNull(executor);
		mServiceProvider = Objects.requireNonNull(provider);
		mTag = "ServiceHolder: " + serviceName;
		mServiceProvider.registerForNotifications(mServiceName, mServiceListener);
		}

		/**
		* Add tasks to run when service becomes available. Ran on the executor provided at
		* construction. Note, for convenience, if the service is already connected, the task is
		* immediately run.
		*/
		public void registerOnStartTask(Consumer<I> task) {
		mOnStartTasks.add(task);
		I i;
		if ((i = mService.get()) != null) {
		mExecutor.execute(() -> task.accept(i));
		}
		}

		public void unregisterOnStartTask(Consumer<I> task) {
		mOnStartTasks.remove(task);
		}

		/**
		* Add tasks to run when service goes down. Ran on the executor provided at construction. Should
		* be called before getService to avoid dropping a death notification.
		*/
		public void registerOnDeathTask(Consumer<I> task) {
		mOnDeathTasks.add(task);
		}

		public void unregisterOnDeathTask(Consumer<I> task) {
		mOnDeathTasks.remove(task);
		}

		@Override
		public void binderDied(@NonNull IBinder who) {
		attemptClear(who);
		}

		@Override
		public void binderDied() {
		throw new AssertionError("Wrong binderDied called, this should never happen");
		}

		/**
		* Notify the holder that the service has gone done, usually in response to a RemoteException.
		* Equivalent to receiving a binder death notification.
		*/
		public void attemptClear(IBinder who) {
		// Possibly prone to weird races, resulting in spurious dead/revive,
		// but that should be fine.
		var current = mService.get();
		if (current != null
		&& Objects.equals(current.asBinder(), who)
		&& mService.compareAndSet(current, null)) {
		who.unlinkToDeath(this, 0);
		for (var r : mOnDeathTasks) {
		mExecutor.execute(() -> r.accept(current));
		}
		}
		}

		/** Get the service, without blocking. Can trigger start tasks, on the provided executor. */
		public @Nullable I checkService() {
		var s = mService.get();
		if (s != null) return s;
		IBinder registered = mServiceProvider.checkService(mServiceName);
		if (registered == null) return null;
		return onServiceInited(registered);
		}

		/** Get the service, but block. Can trigger start tasks, on the provided executor. */
		public @NonNull I waitForService() {
		var s = mService.get();
		return (s != null) ? s : onServiceInited(mServiceProvider.waitForService(mServiceName));
		}

		/*
		* Called when the native service is initialized.
		*/
		private @NonNull I onServiceInited(@NonNull IBinder who) {
		var service = mCastFunction.apply(who);
		Objects.requireNonNull(service);
		if (!mService.compareAndSet(null, service)) {
		return service;
		}
		// Even if the service has immediately died, we should perform these tasks for consistency
		for (var r : mOnStartTasks) {
		mExecutor.execute(() -> r.accept(service));
		}
		try {
		who.linkToDeath(this, 0);
		} catch (RemoteException e) {
		Log.e(mTag, "Immediate service death. Service crash-looping");
		attemptClear(who);
		}
		// This interface is non-null, but could represent a dead object
		return service;
		}
		}

services/tests/servicestests/src/com/android/server/audio/ServiceHolderTest.java

0 → 100644

+284 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2024 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 com.android.server.audio;

		import static com.google.common.truth.Truth.assertThat;

		import static org.mockito.ArgumentMatchers.any;
		import static org.mockito.ArgumentMatchers.anyInt;
		import static org.mockito.ArgumentMatchers.eq;
		import static org.mockito.Mockito.any;
		import static org.mockito.Mockito.mock;
		import static org.mockito.Mockito.never;
		import static org.mockito.Mockito.verify;
		import static org.mockito.Mockito.when;

		import android.media.IAudioPolicyService;
		import android.os.Binder;
		import android.os.IBinder;
		import android.os.IServiceCallback;
		import android.os.RemoteException;
		import android.platform.test.annotations.Presubmit;

		import androidx.test.ext.junit.runners.AndroidJUnit4;

		import org.junit.Before;
		import org.junit.Rule;
		import org.junit.Test;
		import org.junit.runner.RunWith;
		import org.mockito.ArgumentCaptor;
		import org.mockito.ArgumentMatchers;
		import org.mockito.Mock;
		import org.mockito.junit.MockitoJUnit;
		import org.mockito.junit.MockitoRule;

		import java.util.concurrent.Executor;
		import java.util.function.Consumer;
		import java.util.function.Function;

		@RunWith(AndroidJUnit4.class)
		@Presubmit
		public class ServiceHolderTest {

		private static final String AUDIO_POLICY_SERVICE_NAME = "media.audio_policy";

		@Rule
		public final MockitoRule mockito = MockitoJUnit.rule();

		// the actual class under test
		private ServiceHolder<IAudioPolicyService> mServiceHolder;

		@Mock private ServiceHolder.ServiceProviderFacade mServiceProviderFacade;

		@Mock private IAudioPolicyService mAudioPolicyService;

		@Mock private IBinder mBinder;

		@Mock private Consumer<IAudioPolicyService> mTaskOne;
		@Mock private Consumer<IAudioPolicyService> mTaskTwo;

		@Before
		public void setUp() throws Exception {
		mServiceHolder =
		new ServiceHolder(
		AUDIO_POLICY_SERVICE_NAME,
		(Function<IBinder, IAudioPolicyService>)
		binder -> {
		if (binder == mBinder) {
		return mAudioPolicyService;
		} else {
		return mock(IAudioPolicyService.class);
		}
		},
		r -> r.run(),
		mServiceProviderFacade);
		when(mAudioPolicyService.asBinder()).thenReturn(mBinder);
		}

		@Test
		public void testListenerRegistered_whenConstructed() {
		verify(mServiceProviderFacade)
		.registerForNotifications(eq(AUDIO_POLICY_SERVICE_NAME), ArgumentMatchers.any());
		}

		@Test
		public void testServiceSuccessfullyPopulated_whenCallback() throws RemoteException {
		initializeViaCallback();
		verify(mBinder).linkToDeath(any(), anyInt());
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);
		}

		@Test
		public void testCheckServiceCalled_whenUncached() {
		when(mServiceProviderFacade.checkService(eq(AUDIO_POLICY_SERVICE_NAME)))
		.thenReturn(mBinder);
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);
		}

		@Test
		public void testCheckServiceTransmitsNull() {
		assertThat(mServiceHolder.checkService()).isEqualTo(null);
		}

		@Test
		public void testWaitForServiceCalled_whenUncached() {
		when(mServiceProviderFacade.waitForService(eq(AUDIO_POLICY_SERVICE_NAME)))
		.thenReturn(mBinder);
		assertThat(mServiceHolder.waitForService()).isEqualTo(mAudioPolicyService);
		}

		@Test
		public void testCheckServiceNotCalled_whenCached() {
		initializeViaCallback();
		mServiceHolder.checkService();
		verify(mServiceProviderFacade, never()).checkService(any());
		}

		@Test
		public void testWaitForServiceNotCalled_whenCached() {
		initializeViaCallback();
		mServiceHolder.waitForService();
		verify(mServiceProviderFacade, never()).waitForService(any());
		}

		@Test
		public void testStartTaskCalled_onStart() {
		mServiceHolder.registerOnStartTask(mTaskOne);
		mServiceHolder.registerOnStartTask(mTaskTwo);
		mServiceHolder.unregisterOnStartTask(mTaskOne);
		when(mServiceProviderFacade.checkService(eq(AUDIO_POLICY_SERVICE_NAME)))
		.thenReturn(mBinder);

		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);

		verify(mTaskTwo).accept(eq(mAudioPolicyService));
		verify(mTaskOne, never()).accept(any());
		}

		@Test
		public void testStartTaskCalled_onStartFromCallback() {
		mServiceHolder.registerOnStartTask(mTaskOne);
		mServiceHolder.registerOnStartTask(mTaskTwo);
		mServiceHolder.unregisterOnStartTask(mTaskOne);

		initializeViaCallback();

		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);
		verify(mTaskTwo).accept(eq(mAudioPolicyService));
		verify(mTaskOne, never()).accept(any());
		}

		@Test
		public void testStartTaskCalled_onRegisterAfterStarted() {
		initializeViaCallback();
		mServiceHolder.registerOnStartTask(mTaskOne);
		verify(mTaskOne).accept(eq(mAudioPolicyService));
		}

		@Test
		public void testBinderDied_clearsServiceAndUnlinks() {
		initializeViaCallback();
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);

		mServiceHolder.binderDied(mBinder);

		verify(mBinder).unlinkToDeath(any(), anyInt());
		assertThat(mServiceHolder.checkService()).isEqualTo(null);
		verify(mServiceProviderFacade).checkService(eq(AUDIO_POLICY_SERVICE_NAME));
		}

		@Test
		public void testBinderDied_callsDeathTasks() {
		mServiceHolder.registerOnDeathTask(mTaskOne);
		mServiceHolder.registerOnDeathTask(mTaskTwo);
		initializeViaCallback();
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);
		mServiceHolder.unregisterOnDeathTask(mTaskOne);

		mServiceHolder.binderDied(mBinder);

		verify(mTaskTwo).accept(eq(mAudioPolicyService));
		verify(mTaskOne, never()).accept(any());
		}

		@Test
		public void testAttemptClear_clearsServiceAndUnlinks() {
		initializeViaCallback();
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);

		mServiceHolder.attemptClear(mBinder);

		verify(mBinder).unlinkToDeath(any(), anyInt());
		assertThat(mServiceHolder.checkService()).isEqualTo(null);
		verify(mServiceProviderFacade).checkService(eq(AUDIO_POLICY_SERVICE_NAME));
		}

		@Test
		public void testAttemptClear_callsDeathTasks() {
		mServiceHolder.registerOnDeathTask(mTaskOne);
		mServiceHolder.registerOnDeathTask(mTaskTwo);
		initializeViaCallback();
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);
		mServiceHolder.unregisterOnDeathTask(mTaskOne);

		mServiceHolder.attemptClear(mBinder);

		verify(mTaskTwo).accept(eq(mAudioPolicyService));
		verify(mTaskOne, never()).accept(any());
		}

		@Test
		public void testSet_whenServiceSet_isIgnored() {
		mServiceHolder.registerOnStartTask(mTaskOne);
		when(mServiceProviderFacade.checkService(eq(AUDIO_POLICY_SERVICE_NAME)))
		.thenReturn(mBinder);
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);

		verify(mTaskOne).accept(eq(mAudioPolicyService));

		// get the callback
		ArgumentCaptor<IServiceCallback> cb = ArgumentCaptor.forClass(IServiceCallback.class);
		verify(mServiceProviderFacade)
		.registerForNotifications(eq(AUDIO_POLICY_SERVICE_NAME), cb.capture());

		// Simulate a service callback with a different instance
		try {
		cb.getValue().onRegistration(AUDIO_POLICY_SERVICE_NAME, new Binder());
		} catch (RemoteException e) {
		throw new RuntimeException(e);
		}

		// No additional start task call (i.e. only the first verify)
		verify(mTaskOne).accept(any());
		// Same instance
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);

		}

		@Test
		public void testClear_whenServiceCleared_isIgnored() {
		mServiceHolder.registerOnDeathTask(mTaskOne);
		mServiceHolder.attemptClear(mBinder);
		verify(mTaskOne, never()).accept(any());
		}

		@Test
		public void testClear_withDifferentCookie_isIgnored() {
		mServiceHolder.registerOnDeathTask(mTaskOne);
		initializeViaCallback();
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);

		// Notif for stale cookie
		mServiceHolder.attemptClear(new Binder());

		// Service shouldn't be cleared
		assertThat(mServiceHolder.checkService()).isEqualTo(mAudioPolicyService);
		// No death tasks should fire
		verify(mTaskOne, never()).accept(any());
		}

		private void initializeViaCallback() {
		ArgumentCaptor<IServiceCallback> cb = ArgumentCaptor.forClass(IServiceCallback.class);
		verify(mServiceProviderFacade)
		.registerForNotifications(eq(AUDIO_POLICY_SERVICE_NAME), cb.capture());

		try {
		cb.getValue().onRegistration(AUDIO_POLICY_SERVICE_NAME, mBinder);
		} catch (RemoteException e) {
		throw new RuntimeException(e);
		}
		}
		}