| // |
| // ======================================================================== |
| // Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd. |
| // ------------------------------------------------------------------------ |
| // All rights reserved. This program and the accompanying materials |
| // are made available under the terms of the Eclipse Public License v1.0 |
| // and Apache License v2.0 which accompanies this distribution. |
| // |
| // The Eclipse Public License is available at |
| // http://www.eclipse.org/legal/epl-v10.html |
| // |
| // The Apache License v2.0 is available at |
| // http://www.opensource.org/licenses/apache2.0.php |
| // |
| // You may elect to redistribute this code under either of these licenses. |
| // ======================================================================== |
| // |
| |
| package org.eclipse.jetty.util; |
| |
| |
| /* ------------------------------------------------------------ */ |
| /** Iterating Nested Callback. |
| * <p>This specialized callback is used when breaking up an |
| * asynchronous task into smaller asynchronous tasks. A typical pattern |
| * is that a successful callback is used to schedule the next sub task, but |
| * if that task completes quickly and uses the calling thread to callback |
| * the success notification, this can result in a growing stack depth. |
| * </p> |
| * <p>To avoid this issue, this callback uses an AtomicBoolean to note |
| * if the success callback has been called during the processing of a |
| * sub task, and if so then the processing iterates rather than recurses. |
| * </p> |
| * <p>This callback is passed to the asynchronous handling of each sub |
| * task and a call the {@link #succeeded()} on this call back represents |
| * completion of the subtask. Only once all the subtasks are completed is |
| * the {@link Callback#succeeded()} method called on the {@link Callback} instance |
| * passed the the {@link #IteratingNestedCallback(Callback)} constructor.</p> |
| * |
| */ |
| public abstract class IteratingNestedCallback extends IteratingCallback |
| { |
| final Callback _callback; |
| |
| public IteratingNestedCallback(Callback callback) |
| { |
| _callback=callback; |
| } |
| |
| @Override |
| protected void onCompleteSuccess() |
| { |
| _callback.succeeded(); |
| } |
| |
| @Override |
| protected void onCompleteFailure(Throwable x) |
| { |
| _callback.failed(x); |
| } |
| |
| @Override |
| public String toString() |
| { |
| return String.format("%s@%x",getClass().getSimpleName(),hashCode()); |
| } |
| } |