| /* |
| * Copyright (C) 2019 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.systemui.util.concurrency; |
| |
| import com.android.systemui.util.time.FakeSystemClock; |
| |
| import java.util.Collections; |
| import java.util.PriorityQueue; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| public class FakeExecutor implements DelayableExecutor { |
| private final FakeSystemClock mClock; |
| private PriorityQueue<QueuedRunnable> mQueuedRunnables = new PriorityQueue<>(); |
| private boolean mIgnoreClockUpdates; |
| private boolean mExecuting; |
| |
| /** |
| * Initializes a fake executor. |
| * |
| * @param clock FakeSystemClock allowing control over delayed runnables. It is strongly |
| * recommended that this clock have its auto-increment setting set to false to |
| * prevent unexpected advancement of the time. |
| */ |
| public FakeExecutor(FakeSystemClock clock) { |
| mClock = clock; |
| mClock.addListener(() -> { |
| if (!mIgnoreClockUpdates) { |
| runAllReady(); |
| } |
| }); |
| } |
| |
| /** |
| * Runs a single runnable if it's scheduled to run according to the internal clock. |
| * |
| * If constructed to advance the clock automatically, this will advance the clock enough to |
| * run the next pending item. |
| * |
| * This method does not advance the clock past the item that was run. |
| * |
| * @return Returns true if an item was run. |
| */ |
| public boolean runNextReady() { |
| if (!mQueuedRunnables.isEmpty() && mQueuedRunnables.peek().mWhen <= mClock.uptimeMillis()) { |
| mExecuting = true; |
| mQueuedRunnables.poll().mRunnable.run(); |
| mExecuting = false; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Runs all Runnables that are scheduled to run according to the internal clock. |
| * |
| * If constructed to advance the clock automatically, this will advance the clock enough to |
| * run all the pending items. This method does not advance the clock past items that were |
| * run. It is equivalent to calling {@link #runNextReady()} in a loop. |
| * |
| * @return Returns the number of items that ran. |
| */ |
| public int runAllReady() { |
| int num = 0; |
| while (runNextReady()) { |
| num++; |
| } |
| |
| return num; |
| } |
| |
| /** |
| * Advances the internal clock to the next item to run. |
| * |
| * The clock will only move forward. If the next item is set to run in the past or there is no |
| * next item, the clock does not change. |
| * |
| * Note that this will cause one or more items to actually run. |
| * |
| * @return The delta in uptimeMillis that the clock advanced, or 0 if the clock did not advance. |
| */ |
| public long advanceClockToNext() { |
| if (mQueuedRunnables.isEmpty()) { |
| return 0; |
| } |
| |
| long startTime = mClock.uptimeMillis(); |
| long nextTime = mQueuedRunnables.peek().mWhen; |
| if (nextTime <= startTime) { |
| return 0; |
| } |
| updateClock(nextTime); |
| |
| return nextTime - startTime; |
| } |
| |
| |
| /** |
| * Advances the internal clock to the last item to run. |
| * |
| * The clock will only move forward. If the last item is set to run in the past or there is no |
| * next item, the clock does not change. |
| * |
| * @return The delta in uptimeMillis that the clock advanced, or 0 if the clock did not advance. |
| */ |
| public long advanceClockToLast() { |
| if (mQueuedRunnables.isEmpty()) { |
| return 0; |
| } |
| |
| long startTime = mClock.uptimeMillis(); |
| long nextTime = Collections.max(mQueuedRunnables).mWhen; |
| if (nextTime <= startTime) { |
| return 0; |
| } |
| |
| updateClock(nextTime); |
| |
| return nextTime - startTime; |
| } |
| |
| /** |
| * Returns the number of un-executed runnables waiting to run. |
| */ |
| public int numPending() { |
| return mQueuedRunnables.size(); |
| } |
| |
| @Override |
| public Runnable executeDelayed(Runnable r, long delay, TimeUnit unit) { |
| if (delay < 0) { |
| delay = 0; |
| } |
| return executeAtTime(r, mClock.uptimeMillis() + unit.toMillis(delay)); |
| } |
| |
| @Override |
| public Runnable executeAtTime(Runnable r, long uptime, TimeUnit unit) { |
| long uptimeMillis = unit.toMillis(uptime); |
| |
| QueuedRunnable container = new QueuedRunnable(r, uptimeMillis); |
| |
| mQueuedRunnables.offer(container); |
| |
| return () -> mQueuedRunnables.remove(container); |
| } |
| |
| @Override |
| public void execute(Runnable command) { |
| executeDelayed(command, 0); |
| } |
| |
| public boolean isExecuting() { |
| return mExecuting; |
| } |
| |
| /** |
| * Run all Executors in a loop until they all report they have no ready work to do. |
| * |
| * Useful if you have Executors the post work to other Executors, and you simply want to |
| * run them all until they stop posting work. |
| */ |
| public static void exhaustExecutors(FakeExecutor ...executors) { |
| boolean didAnything; |
| do { |
| didAnything = false; |
| for (FakeExecutor executor : executors) { |
| didAnything = didAnything || executor.runAllReady() != 0; |
| } |
| } while (didAnything); |
| } |
| |
| private void updateClock(long nextTime) { |
| mIgnoreClockUpdates = true; |
| mClock.setUptimeMillis(nextTime); |
| mIgnoreClockUpdates = false; |
| } |
| |
| private static class QueuedRunnable implements Comparable<QueuedRunnable> { |
| private static AtomicInteger sCounter = new AtomicInteger(); |
| |
| Runnable mRunnable; |
| long mWhen; |
| private int mCounter; |
| |
| private QueuedRunnable(Runnable r, long when) { |
| mRunnable = r; |
| mWhen = when; |
| |
| // PrioirityQueue orders items arbitrarily when equal. We want to ensure that |
| // otherwise-equal elements are ordered according to their insertion order. Because this |
| // class only is constructed right before insertion, we use a static counter to track |
| // insertion order of otherwise equal elements. |
| mCounter = sCounter.incrementAndGet(); |
| } |
| |
| @Override |
| public int compareTo(QueuedRunnable other) { |
| long diff = mWhen - other.mWhen; |
| |
| if (diff == 0) { |
| return mCounter - other.mCounter; |
| } |
| |
| return diff > 0 ? 1 : -1; |
| } |
| } |
| } |