| /* |
| * 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 com.android.server.testutils; |
| |
| |
| import static android.util.ExceptionUtils.appendCause; |
| import static android.util.ExceptionUtils.propagate; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Message; |
| import android.os.SystemClock; |
| import android.util.ArrayMap; |
| |
| import java.util.Map; |
| import java.util.PriorityQueue; |
| import java.util.function.LongSupplier; |
| |
| /** |
| * A test {@link Handler} that stores incoming {@link Message}s and {@link Runnable callbacks} |
| * in a {@link PriorityQueue} based on time, to be manually processed later in a correct order |
| * either all together with {@link #flush}, or only those due at the current time with |
| * {@link #timeAdvance}. |
| * |
| * For the latter use case this also supports providing a custom clock (in a format of a |
| * milliseconds-returning {@link LongSupplier}), that will be used for storing the messages' |
| * timestamps to be posted at, and checked against during {@link #timeAdvance}. |
| * |
| * This allows to test code that uses {@link Handler}'s delayed invocation capabilities, such as |
| * {@link Handler#sendMessageDelayed} or {@link Handler#postDelayed} without resorting to |
| * synchronously {@link Thread#sleep}ing in your test. |
| * |
| * @see OffsettableClock for a useful custom clock implementation to use with this handler |
| */ |
| public class TestHandler extends Handler { |
| private static final LongSupplier DEFAULT_CLOCK = SystemClock::uptimeMillis; |
| |
| private final PriorityQueue<MsgInfo> mMessages = new PriorityQueue<>(); |
| /** |
| * Map of: {@code message id -> count of such messages currently pending } |
| */ |
| // Boxing is ok here - both msg ids and their pending counts tend to be well below 128 |
| private final Map<Integer, Integer> mPendingMsgTypeCounts = new ArrayMap<>(); |
| private final LongSupplier mClock; |
| |
| public TestHandler(Callback callback) { |
| this(callback, DEFAULT_CLOCK); |
| } |
| |
| public TestHandler(Callback callback, LongSupplier clock) { |
| super(Looper.getMainLooper(), callback); |
| mClock = clock; |
| } |
| |
| @Override |
| public boolean sendMessageAtTime(Message msg, long uptimeMillis) { |
| mPendingMsgTypeCounts.put(msg.what, |
| mPendingMsgTypeCounts.getOrDefault(msg.what, 0) + 1); |
| |
| // uptimeMillis is an absolute time obtained as SystemClock.uptimeMillis() + offsetMillis |
| // if custom clock is given, recalculate the time with regards to it |
| if (mClock != DEFAULT_CLOCK) { |
| uptimeMillis = uptimeMillis - SystemClock.uptimeMillis() + mClock.getAsLong(); |
| } |
| |
| // post a dummy queue entry to keep track of message removal |
| return super.sendMessageAtTime(msg, Long.MAX_VALUE) |
| && mMessages.add(new MsgInfo(Message.obtain(msg), uptimeMillis)); |
| } |
| |
| /** @see TestHandler */ |
| public void timeAdvance() { |
| long now = mClock.getAsLong(); |
| while (!mMessages.isEmpty() && mMessages.peek().sendTime <= now) { |
| dispatch(mMessages.poll()); |
| } |
| } |
| |
| /** |
| * Dispatch all messages in order |
| * |
| * @see TestHandler |
| */ |
| public void flush() { |
| MsgInfo msg; |
| while ((msg = mMessages.poll()) != null) { |
| dispatch(msg); |
| } |
| } |
| |
| public PriorityQueue<MsgInfo> getPendingMessages() { |
| return new PriorityQueue<>(mMessages); |
| } |
| |
| /** |
| * Optionally-overridable to allow deciphering message types |
| * |
| * @see android.util.DebugUtils#valueToString - a handy utility to use when overriding this |
| */ |
| protected String messageToString(Message message) { |
| return message.toString(); |
| } |
| |
| private void dispatch(MsgInfo msg) { |
| int msgId = msg.message.what; |
| |
| if (!hasMessages(msgId)) { |
| // Handler.removeMessages(msgId) must have been called |
| return; |
| } |
| |
| try { |
| Integer pendingMsgCount = mPendingMsgTypeCounts.getOrDefault(msgId, 0); |
| if (pendingMsgCount <= 1) { |
| removeMessages(msgId); |
| } |
| mPendingMsgTypeCounts.put(msgId, pendingMsgCount - 1); |
| |
| dispatchMessage(msg.message); |
| } catch (Throwable t) { |
| // Append stack trace of this message being posted as a cause for a helpful |
| // test error message |
| throw propagate(appendCause(t, msg.postPoint)); |
| } finally { |
| msg.message.recycle(); |
| } |
| } |
| |
| private class MsgInfo implements Comparable<MsgInfo> { |
| public final Message message; |
| public final long sendTime; |
| public final RuntimeException postPoint; |
| |
| private MsgInfo(Message message, long sendTime) { |
| this.message = message; |
| this.sendTime = sendTime; |
| this.postPoint = new RuntimeException("Message originated from here:"); |
| } |
| |
| @Override |
| public int compareTo(MsgInfo o) { |
| return Long.compare(sendTime, o.sendTime); |
| } |
| |
| @Override |
| public String toString() { |
| return "MsgInfo{" + |
| "message=" + messageToString(message) + |
| ", sendTime=" + sendTime + |
| '}'; |
| } |
| } |
| } |