From fcc7b9694ee1fef20f12d21bdea193362fa1874b Mon Sep 17 00:00:00 2001
From: markb74 <57717302+markb74@users.noreply.github.com>
Date: Wed, 29 Sep 2021 20:04:47 +0200
Subject: [PATCH] Add LifecycleOnDestroyHelper to support shutdown of
channel/server on Android lifecycle changes (#8568)
---
binder/build.gradle | 3 +
.../grpc/binder/LifecycleOnDestroyHelper.java | 85 ++++++++++++++++
.../binder/LifecycleOnDestroyHelperTest.java | 96 +++++++++++++++++++
build.gradle | 1 +
4 files changed, 185 insertions(+)
create mode 100644 binder/src/main/java/io/grpc/binder/LifecycleOnDestroyHelper.java
create mode 100644 binder/src/test/java/io/grpc/binder/LifecycleOnDestroyHelperTest.java
diff --git a/binder/build.gradle b/binder/build.gradle
index 537c23a009..81606d4726 100644
--- a/binder/build.gradle
+++ b/binder/build.gradle
@@ -49,9 +49,12 @@ dependencies {
implementation libraries.androidx_annotation
implementation libraries.androidx_core
+ implementation libraries.androidx_lifecycle_common
implementation libraries.guava
testImplementation libraries.androidx_core
testImplementation libraries.androidx_test
+ testImplementation libraries.androidx_lifecycle_common
+ testImplementation libraries.androidx_lifecycle_service
testImplementation libraries.junit
testImplementation libraries.mockito
testImplementation (libraries.robolectric) {
diff --git a/binder/src/main/java/io/grpc/binder/LifecycleOnDestroyHelper.java b/binder/src/main/java/io/grpc/binder/LifecycleOnDestroyHelper.java
new file mode 100644
index 0000000000..8631bac0df
--- /dev/null
+++ b/binder/src/main/java/io/grpc/binder/LifecycleOnDestroyHelper.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2021 The gRPC Authors
+ *
+ * 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 io.grpc.binder;
+
+import androidx.annotation.MainThread;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.Lifecycle.State;
+import androidx.lifecycle.LifecycleEventObserver;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.LifecycleOwner;
+import io.grpc.ManagedChannel;
+import io.grpc.Server;
+
+/**
+ * Helps work around certain quirks of {@link Lifecycle#addObserver} and {@link State#DESTROYED}.
+ *
+ * In particular, calls to {@link Lifecycle#addObserver(LifecycleObserver)} are silently ignored
+ * if the owner is already destroyed.
+ */
+public final class LifecycleOnDestroyHelper {
+
+ private LifecycleOnDestroyHelper() {}
+
+ /**
+ * Arranges for {@link ManagedChannel#shutdownNow()} to be called on {@code channel} just before
+ * {@code lifecycle} is destroyed, or immediately if {@code lifecycle} is already destroyed.
+ *
+ *
Must only be called on the application's main thread.
+ */
+ @MainThread
+ public static void shutdownUponDestruction(Lifecycle lifecycle, ManagedChannel channel) {
+ if (lifecycle.getCurrentState() == State.DESTROYED) {
+ channel.shutdownNow();
+ } else {
+ lifecycle.addObserver(
+ new LifecycleEventObserver() {
+ @Override
+ public void onStateChanged(LifecycleOwner source, Lifecycle.Event event) {
+ if (event == Lifecycle.Event.ON_DESTROY) {
+ source.getLifecycle().removeObserver(this);
+ channel.shutdownNow();
+ }
+ }
+ });
+ }
+ }
+
+ /**
+ * Arranges for {@link Server#shutdownNow()} to be called on {@code server} just before {@code
+ * lifecycle} is destroyed, or immediately if {@code lifecycle} is already destroyed.
+ *
+ *
Must only be called on the application's main thread.
+ */
+ @MainThread
+ public static void shutdownUponDestruction(Lifecycle lifecycle, Server server) {
+ if (lifecycle.getCurrentState() == State.DESTROYED) {
+ server.shutdownNow();
+ } else {
+ lifecycle.addObserver(
+ new LifecycleEventObserver() {
+ @Override
+ public void onStateChanged(LifecycleOwner source, Lifecycle.Event event) {
+ if (event == Lifecycle.Event.ON_DESTROY) {
+ source.getLifecycle().removeObserver(this);
+ server.shutdownNow();
+ }
+ }
+ });
+ }
+ }
+}
diff --git a/binder/src/test/java/io/grpc/binder/LifecycleOnDestroyHelperTest.java b/binder/src/test/java/io/grpc/binder/LifecycleOnDestroyHelperTest.java
new file mode 100644
index 0000000000..48365204f7
--- /dev/null
+++ b/binder/src/test/java/io/grpc/binder/LifecycleOnDestroyHelperTest.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2021 The gRPC Authors
+ *
+ * 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 io.grpc.binder;
+
+import static android.os.Looper.getMainLooper;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoInteractions;
+import static org.robolectric.Shadows.shadowOf;
+
+import androidx.lifecycle.LifecycleService;
+import io.grpc.ManagedChannel;
+import io.grpc.Server;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+import org.robolectric.Robolectric;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.android.controller.ServiceController;
+
+@RunWith(RobolectricTestRunner.class)
+public final class LifecycleOnDestroyHelperTest {
+
+ @Rule public final MockitoRule mocks = MockitoJUnit.rule();
+
+ private ServiceController sourceController;
+ private MyService sourceService;
+
+ @Mock ManagedChannel mockChannel;
+ @Mock Server mockServer;
+
+ @Before
+ public void setup() {
+ sourceController = Robolectric.buildService(MyService.class);
+ sourceService = sourceController.create().get();
+ }
+
+ @Test
+ public void shouldShutdownChannelUponSourceDestruction() {
+ LifecycleOnDestroyHelper.shutdownUponDestruction(sourceService.getLifecycle(), mockChannel);
+ shadowOf(getMainLooper()).idle();
+ verifyNoInteractions(mockChannel);
+
+ sourceController.destroy();
+ shadowOf(getMainLooper()).idle();
+ verify(mockChannel).shutdownNow();
+ }
+
+ @Test
+ public void shouldShutdownChannelForInitiallyDestroyedSource() {
+ sourceController.destroy();
+ shadowOf(getMainLooper()).idle();
+
+ LifecycleOnDestroyHelper.shutdownUponDestruction(sourceService.getLifecycle(), mockChannel);
+ verify(mockChannel).shutdownNow();
+ }
+
+ @Test
+ public void shouldShutdownServerUponServiceDestruction() {
+ LifecycleOnDestroyHelper.shutdownUponDestruction(sourceService.getLifecycle(), mockServer);
+ shadowOf(getMainLooper()).idle();
+ verifyNoInteractions(mockServer);
+
+ sourceController.destroy();
+ shadowOf(getMainLooper()).idle();
+ verify(mockServer).shutdownNow();
+ }
+
+ @Test
+ public void shouldShutdownServerForInitiallyDestroyedSource() {
+ sourceController.destroy();
+ shadowOf(getMainLooper()).idle();
+
+ LifecycleOnDestroyHelper.shutdownUponDestruction(sourceService.getLifecycle(), mockServer);
+ verify(mockServer).shutdownNow();
+ }
+
+ private static class MyService extends LifecycleService {}
+}
diff --git a/build.gradle b/build.gradle
index 3c746a9dab..df487de8fc 100644
--- a/build.gradle
+++ b/build.gradle
@@ -191,6 +191,7 @@ subprojects {
guava_testlib: "com.google.guava:guava-testlib:${guavaVersion}",
androidx_annotation: "androidx.annotation:annotation:1.1.0",
androidx_core: "androidx.core:core:1.3.0",
+ androidx_lifecycle_common: "androidx.lifecycle:lifecycle-common:2.3.0",
androidx_lifecycle_service: "androidx.lifecycle:lifecycle-service:2.3.0",
androidx_test: "androidx.test:core:1.3.0",
androidx_test_rules: "androidx.test:rules:1.3.0",