1 /*
2 * Copyright 2002-2013 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.scheduling;
18
19 import org.springframework.core.task.AsyncTaskExecutor;
20
21 /**
22 * A {@link org.springframework.core.task.TaskExecutor} extension exposing
23 * scheduling characteristics that are relevant to potential task submitters.
24 *
25 * <p>Scheduling clients are encouraged to submit
26 * {@link Runnable Runnables} that match the exposed preferences
27 * of the {@code TaskExecutor} implementation in use.
28 *
29 * <p>Note: {@link SchedulingTaskExecutor} implementations are encouraged to also
30 * implement the {@link org.springframework.core.task.AsyncListenableTaskExecutor}
31 * interface. This is not required due to the dependency on Spring 4.0's new
32 * {@link org.springframework.util.concurrent.ListenableFuture} interface,
33 * which would make it impossible for third-party executor implementations
34 * to remain compatible with both Spring 4.0 and Spring 3.x.
35 *
36 * @author Juergen Hoeller
37 * @since 2.0
38 * @see SchedulingAwareRunnable
39 * @see org.springframework.core.task.TaskExecutor
40 * @see org.springframework.scheduling.commonj.WorkManagerTaskExecutor
41 */
42 public interface SchedulingTaskExecutor extends AsyncTaskExecutor {
43
44 /**
45 * Does this {@code TaskExecutor} prefer short-lived tasks over
46 * long-lived tasks?
47 * <p>A {@code SchedulingTaskExecutor} implementation can indicate
48 * whether it prefers submitted tasks to perform as little work as they
49 * can within a single task execution. For example, submitted tasks
50 * might break a repeated loop into individual subtasks which submit a
51 * follow-up task afterwards (if feasible).
52 * <p>This should be considered a hint. Of course {@code TaskExecutor}
53 * clients are free to ignore this flag and hence the
54 * {@code SchedulingTaskExecutor} interface overall. However, thread
55 * pools will usually indicated a preference for short-lived tasks, to be
56 * able to perform more fine-grained scheduling.
57 * @return {@code true} if this {@code TaskExecutor} prefers
58 * short-lived tasks
59 */
60 boolean prefersShortLivedTasks();
61
62 }