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/*
* Copyright (C) 2017 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.testing;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.os.MessageQueue;
import android.os.TestLooperManager;
import android.util.ArrayMap;
import androidx.test.InstrumentationRegistry;
import org.junit.runners.model.FrameworkMethod;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Field;
import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* This is a wrapper around {@link TestLooperManager} to make it easier to manage
* and provide an easy annotation for use with tests.
*
* @see TestableLooperTest TestableLooperTest for examples.
*/
public class TestableLooper {
/**
* Whether to hold onto the main thread through all tests in an attempt to
* catch crashes.
*/
public static final boolean HOLD_MAIN_THREAD = false;
private static final Field MESSAGE_QUEUE_MESSAGES_FIELD;
private static final Field MESSAGE_NEXT_FIELD;
private static final Field MESSAGE_WHEN_FIELD;
private Looper mLooper;
private MessageQueue mQueue;
private MessageHandler mMessageHandler;
private Handler mHandler;
private TestLooperManager mQueueWrapper;
static {
try {
MESSAGE_QUEUE_MESSAGES_FIELD = MessageQueue.class.getDeclaredField("mMessages");
MESSAGE_QUEUE_MESSAGES_FIELD.setAccessible(true);
MESSAGE_NEXT_FIELD = Message.class.getDeclaredField("next");
MESSAGE_NEXT_FIELD.setAccessible(true);
MESSAGE_WHEN_FIELD = Message.class.getDeclaredField("when");
MESSAGE_WHEN_FIELD.setAccessible(true);
} catch (NoSuchFieldException e) {
throw new RuntimeException("Failed to initialize TestableLooper", e);
}
}
public TestableLooper(Looper l) throws Exception {
this(acquireLooperManager(l), l);
}
private TestableLooper(TestLooperManager wrapper, Looper l) {
mQueueWrapper = wrapper;
setupQueue(l);
}
private TestableLooper(Looper looper, boolean b) {
setupQueue(looper);
}
public Looper getLooper() {
return mLooper;
}
private void setupQueue(Looper l) {
mLooper = l;
mQueue = mLooper.getQueue();
mHandler = new Handler(mLooper);
}
/**
* Must be called to release the looper when the test is complete, otherwise
* the looper will not be available for any subsequent tests. This is
* automatically handled for tests using {@link RunWithLooper}.
*/
public void destroy() {
mQueueWrapper.release();
if (HOLD_MAIN_THREAD && mLooper == Looper.getMainLooper()) {
TestableInstrumentation.releaseMain();
}
}
/**
* Sets a callback for all messages processed on this TestableLooper.
*
* @see {@link MessageHandler}
*/
public void setMessageHandler(MessageHandler handler) {
mMessageHandler = handler;
}
/**
* Parse num messages from the message queue.
*
* @param num Number of messages to parse
*/
public int processMessages(int num) {
return processMessagesInternal(num, null);
}
private int processMessagesInternal(int num, Runnable barrierRunnable) {
for (int i = 0; i < num; i++) {
if (!processSingleMessage(barrierRunnable)) {
return i + 1;
}
}
return num;
}
/**
* Process up to a certain number of messages, not blocking if the queue has less messages than
* that
* @param num the maximum number of messages to process
* @return the number of messages processed. This will be at most {@code num}.
*/
public int processMessagesNonBlocking(int num) {
final AtomicBoolean reachedBarrier = new AtomicBoolean(false);
Runnable barrierRunnable = () -> {
reachedBarrier.set(true);
};
mHandler.post(barrierRunnable);
waitForMessage(mQueueWrapper, mHandler, barrierRunnable);
try {
return processMessagesInternal(num, barrierRunnable) + (reachedBarrier.get() ? -1 : 0);
} finally {
mHandler.removeCallbacks(barrierRunnable);
}
}
/**
* Process messages in the queue until no more are found.
*/
public void processAllMessages() {
while (processQueuedMessages() != 0) ;
}
public void moveTimeForward(long milliSeconds) {
try {
Message msg = getMessageLinkedList();
while (msg != null) {
long updatedWhen = msg.getWhen() - milliSeconds;
if (updatedWhen < 0) {
updatedWhen = 0;
}
MESSAGE_WHEN_FIELD.set(msg, updatedWhen);
msg = (Message) MESSAGE_NEXT_FIELD.get(msg);
}
} catch (IllegalAccessException e) {
throw new RuntimeException("Access failed in TestableLooper: set - Message.when", e);
}
}
private Message getMessageLinkedList() {
try {
MessageQueue queue = mLooper.getQueue();
return (Message) MESSAGE_QUEUE_MESSAGES_FIELD.get(queue);
} catch (IllegalAccessException e) {
throw new RuntimeException(
"Access failed in TestableLooper: get - MessageQueue.mMessages",
e);
}
}
private int processQueuedMessages() {
int count = 0;
Runnable barrierRunnable = () -> { };
mHandler.post(barrierRunnable);
waitForMessage(mQueueWrapper, mHandler, barrierRunnable);
while (processSingleMessage(barrierRunnable)) count++;
return count;
}
private boolean processSingleMessage(Runnable barrierRunnable) {
try {
Message result = mQueueWrapper.next();
if (result != null) {
// This is a break message.
if (result.getCallback() == barrierRunnable) {
mQueueWrapper.execute(result);
mQueueWrapper.recycle(result);
return false;
}
if (mMessageHandler != null) {
if (mMessageHandler.onMessageHandled(result)) {
mQueueWrapper.execute(result);
mQueueWrapper.recycle(result);
} else {
mQueueWrapper.recycle(result);
// Message handler indicated it doesn't want us to continue.
return false;
}
} else {
mQueueWrapper.execute(result);
mQueueWrapper.recycle(result);
}
} else {
// No messages, don't continue parsing
return false;
}
} catch (Exception e) {
throw new RuntimeException(e);
}
return true;
}
/**
* Runs an executable with myLooper set and processes all messages added.
*/
public void runWithLooper(RunnableWithException runnable) throws Exception {
new Handler(getLooper()).post(() -> {
try {
runnable.run();
} catch (Exception e) {
throw new RuntimeException(e);
}
});
processAllMessages();
}
public interface RunnableWithException {
void run() throws Exception;
}
/**
* Annotation that tells the {@link AndroidTestingRunner} to create a TestableLooper and
* run this test/class on that thread. The {@link TestableLooper} can be acquired using
* {@link #get(Object)}.
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
public @interface RunWithLooper {
boolean setAsMainLooper() default false;
}
private static void waitForMessage(TestLooperManager queueWrapper, Handler handler,
Runnable execute) {
for (int i = 0; i < 10; i++) {
if (!queueWrapper.hasMessages(handler, null, execute)) {
try {
Thread.sleep(1);
} catch (InterruptedException e) {
}
}
}
if (!queueWrapper.hasMessages(handler, null, execute)) {
throw new RuntimeException("Message didn't queue...");
}
}
private static TestLooperManager acquireLooperManager(Looper l) {
if (HOLD_MAIN_THREAD && l == Looper.getMainLooper()) {
TestableInstrumentation.acquireMain();
}
return InstrumentationRegistry.getInstrumentation().acquireLooperManager(l);
}
private static final Map<Object, TestableLooper> sLoopers = new ArrayMap<>();
/**
* For use with {@link RunWithLooper}, used to get the TestableLooper that was
* automatically created for this test.
*/
public static TestableLooper get(Object test) {
return sLoopers.get(test);
}
public static void remove(Object test) {
sLoopers.remove(test);
}
static class LooperFrameworkMethod extends FrameworkMethod {
private HandlerThread mHandlerThread;
private final TestableLooper mTestableLooper;
private final Looper mLooper;
private final Handler mHandler;
public LooperFrameworkMethod(FrameworkMethod base, boolean setAsMain, Object test) {
super(base.getMethod());
try {
mLooper = setAsMain ? Looper.getMainLooper() : createLooper();
mTestableLooper = new TestableLooper(mLooper, false);
if (!setAsMain) {
mTestableLooper.getLooper().getThread().setName(test.getClass().getName());
}
} catch (Exception e) {
throw new RuntimeException(e);
}
sLoopers.put(test, mTestableLooper);
mHandler = new Handler(mLooper);
}
public LooperFrameworkMethod(TestableLooper other, FrameworkMethod base) {
super(base.getMethod());
mLooper = other.mLooper;
mTestableLooper = other;
mHandler = Handler.createAsync(mLooper);
}
public static FrameworkMethod get(FrameworkMethod base, boolean setAsMain, Object test) {
if (sLoopers.containsKey(test)) {
return new LooperFrameworkMethod(sLoopers.get(test), base);
}
return new LooperFrameworkMethod(base, setAsMain, test);
}
@Override
public Object invokeExplosively(Object target, Object... params) throws Throwable {
if (Looper.myLooper() == mLooper) {
// Already on the right thread from another statement, just execute then.
return super.invokeExplosively(target, params);
}
boolean set = mTestableLooper.mQueueWrapper == null;
if (set) {
mTestableLooper.mQueueWrapper = acquireLooperManager(mLooper);
}
try {
Object[] ret = new Object[1];
// Run the execution on the looper thread.
Runnable execute = () -> {
try {
ret[0] = super.invokeExplosively(target, params);
} catch (Throwable throwable) {
throw new LooperException(throwable);
}
};
Message m = Message.obtain(mHandler, execute);
// Dispatch our message.
try {
mTestableLooper.mQueueWrapper.execute(m);
} catch (LooperException e) {
throw e.getSource();
} catch (RuntimeException re) {
// If the TestLooperManager has to post, it will wrap what it throws in a
// RuntimeException, make sure we grab the actual source.
if (re.getCause() instanceof LooperException) {
throw ((LooperException) re.getCause()).getSource();
} else {
throw re.getCause();
}
} finally {
m.recycle();
}
return ret[0];
} finally {
if (set) {
mTestableLooper.mQueueWrapper.release();
mTestableLooper.mQueueWrapper = null;
if (HOLD_MAIN_THREAD && mLooper == Looper.getMainLooper()) {
TestableInstrumentation.releaseMain();
}
}
}
}
private Looper createLooper() {
// TODO: Find way to share these.
mHandlerThread = new HandlerThread(TestableLooper.class.getSimpleName());
mHandlerThread.start();
return mHandlerThread.getLooper();
}
@Override
protected void finalize() throws Throwable {
super.finalize();
if (mHandlerThread != null) {
mHandlerThread.quit();
}
}
private static class LooperException extends RuntimeException {
private final Throwable mSource;
public LooperException(Throwable t) {
mSource = t;
}
public Throwable getSource() {
return mSource;
}
}
}
/**
* Callback to control the execution of messages on the looper, when set with
* {@link #setMessageHandler(MessageHandler)} then {@link #onMessageHandled(Message)}
* will get called back for every message processed on the {@link TestableLooper}.
*/
public interface MessageHandler {
/**
* Return true to have the message executed and delivered to target.
* Return false to not execute the message and stop executing messages.
*/
boolean onMessageHandled(Message m);
}
}