/* * Copyright (C) 2016 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 org.mozilla.thirdparty.com.google.android.exoplayer2.util; import java.io.IOException; import java.util.Collections; import java.util.PriorityQueue; /** * Allows tasks with associated priorities to control how they proceed relative to one another. *
* A task should call {@link #add(int)} to register with the manager and {@link #remove(int)} to
* unregister. A registered task will prevent tasks of lower priority from proceeding, and should
* call {@link #proceed(int)}, {@link #proceedNonBlocking(int)} or {@link #proceedOrThrow(int)} each
* time it wishes to check whether it is itself allowed to proceed.
*/
public final class PriorityTaskManager {
/**
* Thrown when task attempts to proceed when another registered task has a higher priority.
*/
public static class PriorityTooLowException extends IOException {
public PriorityTooLowException(int priority, int highestPriority) {
super("Priority too low [priority=" + priority + ", highest=" + highestPriority + "]");
}
}
private final Object lock = new Object();
// Guarded by lock.
private final PriorityQueue