001/* 002 * Copyright 2002-2013 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.scheduling; 018 019import org.springframework.core.task.AsyncTaskExecutor; 020 021/** 022 * A {@link org.springframework.core.task.TaskExecutor} extension exposing 023 * scheduling characteristics that are relevant to potential task submitters. 024 * 025 * <p>Scheduling clients are encouraged to submit 026 * {@link Runnable Runnables} that match the exposed preferences 027 * of the {@code TaskExecutor} implementation in use. 028 * 029 * <p>Note: {@link SchedulingTaskExecutor} implementations are encouraged to also 030 * implement the {@link org.springframework.core.task.AsyncListenableTaskExecutor} 031 * interface. This is not required due to the dependency on Spring 4.0's new 032 * {@link org.springframework.util.concurrent.ListenableFuture} interface, 033 * which would make it impossible for third-party executor implementations 034 * to remain compatible with both Spring 4.0 and Spring 3.x. 035 * 036 * @author Juergen Hoeller 037 * @since 2.0 038 * @see SchedulingAwareRunnable 039 * @see org.springframework.core.task.TaskExecutor 040 * @see org.springframework.scheduling.commonj.WorkManagerTaskExecutor 041 */ 042public interface SchedulingTaskExecutor extends AsyncTaskExecutor { 043 044 /** 045 * Does this {@code TaskExecutor} prefer short-lived tasks over 046 * long-lived tasks? 047 * <p>A {@code SchedulingTaskExecutor} implementation can indicate 048 * whether it prefers submitted tasks to perform as little work as they 049 * can within a single task execution. For example, submitted tasks 050 * might break a repeated loop into individual subtasks which submit a 051 * follow-up task afterwards (if feasible). 052 * <p>This should be considered a hint. Of course {@code TaskExecutor} 053 * clients are free to ignore this flag and hence the 054 * {@code SchedulingTaskExecutor} interface overall. However, thread 055 * pools will usually indicated a preference for short-lived tasks, to be 056 * able to perform more fine-grained scheduling. 057 * @return {@code true} if this {@code TaskExecutor} prefers 058 * short-lived tasks 059 */ 060 boolean prefersShortLivedTasks(); 061 062}