1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17 package org.apache.logging.log4j.core.util;
18
19 import java.util.concurrent.ExecutorService;
20 import java.util.concurrent.TimeUnit;
21
22 import org.apache.logging.log4j.Logger;
23 import org.apache.logging.log4j.status.StatusLogger;
24
25 public class ExecutorServices {
26
27 private static final Logger LOGGER = StatusLogger.getLogger();
28
29 /**
30 * Shuts down the given {@link ExecutorService} in an orderly fashion. Disables new tasks from submission and then
31 * waits for existing tasks to terminate. Eventually cancels running tasks if too much time elapses.
32 * <p>
33 * If the timeout is 0, then a plain shutdown takes place.
34 * </p>
35 *
36 * @param executorService
37 * the pool to shutdown.
38 * @param timeout
39 * the maximum time to wait, or 0 to not wait for existing tasks to terminate.
40 * @param timeUnit
41 * the time unit of the timeout argument
42 * @param source
43 * use this string in any log messages.
44 * @return {@code true} if the given executor terminated and {@code false} if the timeout elapsed before
45 * termination.
46 */
47 public static boolean shutdown(final ExecutorService executorService, final long timeout, final TimeUnit timeUnit, final String source) {
48 if (executorService == null || executorService.isTerminated()) {
49 return true;
50 }
51 executorService.shutdown(); // Disable new tasks from being submitted
52 if (timeout > 0 && timeUnit == null) {
53 throw new IllegalArgumentException(
54 String.format("%s can't shutdown %s when timeout = %,d and timeUnit = %s.", source, executorService,
55 timeout, timeUnit));
56 }
57 if (timeout > 0) {
58 try {
59 // Wait a while for existing tasks to terminate
60 if (!executorService.awaitTermination(timeout, timeUnit)) {
61 executorService.shutdownNow(); // Cancel currently executing tasks
62 // Wait a while for tasks to respond to being cancelled
63 if (!executorService.awaitTermination(timeout, timeUnit)) {
64 LOGGER.error("{} pool {} did not terminate after {} {}", source, executorService, timeout,
65 timeUnit);
66 }
67 return false;
68 }
69 } catch (final InterruptedException ie) {
70 // (Re-)Cancel if current thread also interrupted
71 executorService.shutdownNow();
72 // Preserve interrupt status
73 Thread.currentThread().interrupt();
74 }
75 } else {
76 executorService.shutdown();
77 }
78 return true;
79 }
80
81 }