RejectedExecutionHandler.java revision 29957558cf0db700bfaae360a80c42dc3871d0e5 
1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25/*
26 * This file is available under and governed by the GNU General Public
27 * License version 2 only, as published by the Free Software Foundation.
28 * However, the following notice accompanied the original version of this
29 * file:
30 *
31 * Written by Doug Lea with assistance from members of JCP JSR-166
32 * Expert Group and released to the public domain, as explained at
33 * http://creativecommons.org/publicdomain/zero/1.0/
34 */
35
36package java.util.concurrent;
37
38/**
39 * A handler for tasks that cannot be executed by a {@link ThreadPoolExecutor}.
40 *
41 * @since 1.5
42 * @author Doug Lea
43 */
44public interface RejectedExecutionHandler {
45
46    /**
47     * Method that may be invoked by a {@link ThreadPoolExecutor} when
48     * {@link ThreadPoolExecutor#execute execute} cannot accept a
49     * task.  This may occur when no more threads or queue slots are
50     * available because their bounds would be exceeded, or upon
51     * shutdown of the Executor.
52     *
53     * <p>In the absence of other alternatives, the method may throw
54     * an unchecked {@link RejectedExecutionException}, which will be
55     * propagated to the caller of {@code execute}.
56     *
57     * @param r the runnable task requested to be executed
58     * @param executor the executor attempting to execute this task
59     * @throws RejectedExecutionException if there is no remedy
60     */
61    void rejectedExecution(Runnable r, ThreadPoolExecutor executor);
62}
63