/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.scheduling;

import org.springframework.core.task.AsyncTaskExecutor;

A TaskExecutor extension exposing scheduling characteristics that are relevant to potential task submitters. 
Scheduling clients are encouraged to submit Runnables that match the exposed preferences of the TaskExecutor implementation in use. 
Note: SchedulingTaskExecutor implementations are encouraged to also implement the AsyncListenableTaskExecutor interface. This is not required due to the dependency on Spring 4.0's new ListenableFuture interface, which would make it impossible for third-party executor implementations to remain compatible with both Spring 4.0 and Spring 3.x. 
Author:
Juergen Hoeller
See Also:
SchedulingAwareRunnable
TaskExecutor
WorkManagerTaskExecutor
Since:
2.0/**
 * A {@link org.springframework.core.task.TaskExecutor} extension exposing
 * scheduling characteristics that are relevant to potential task submitters.
 *
 * <p>Scheduling clients are encouraged to submit
 * {@link Runnable Runnables} that match the exposed preferences
 * of the {@code TaskExecutor} implementation in use.
 *
 * <p>Note: {@link SchedulingTaskExecutor} implementations are encouraged to also
 * implement the {@link org.springframework.core.task.AsyncListenableTaskExecutor}
 * interface. This is not required due to the dependency on Spring 4.0's new
 * {@link org.springframework.util.concurrent.ListenableFuture} interface,
 * which would make it impossible for third-party executor implementations
 * to remain compatible with both Spring 4.0 and Spring 3.x.
 *
 * @author Juergen Hoeller
 * @since 2.0
 * @see SchedulingAwareRunnable
 * @see org.springframework.core.task.TaskExecutor
 * @see org.springframework.scheduling.commonj.WorkManagerTaskExecutor
 */
public interface SchedulingTaskExecutor extends AsyncTaskExecutor {

	
Does this TaskExecutor prefer short-lived tasks over long-lived tasks? 
A SchedulingTaskExecutor implementation can indicate whether it prefers submitted tasks to perform as little work as they can within a single task execution. For example, submitted tasks might break a repeated loop into individual subtasks which submit a follow-up task afterwards (if feasible). 
This should be considered a hint. Of course TaskExecutor clients are free to ignore this flag and hence the SchedulingTaskExecutor interface overall. However, thread pools will usually indicated a preference for short-lived tasks, allowing for more fine-grained scheduling. 
Returns:
true if this executor prefers short-lived tasks (the default), false otherwise (for treatment like a regular TaskExecutor)/**
	 * Does this {@code TaskExecutor} prefer short-lived tasks over long-lived tasks?
	 * <p>A {@code SchedulingTaskExecutor} implementation can indicate whether it
	 * prefers submitted tasks to perform as little work as they can within a single
	 * task execution. For example, submitted tasks might break a repeated loop into
	 * individual subtasks which submit a follow-up task afterwards (if feasible).
	 * <p>This should be considered a hint. Of course {@code TaskExecutor} clients
	 * are free to ignore this flag and hence the {@code SchedulingTaskExecutor}
	 * interface overall. However, thread pools will usually indicated a preference
	 * for short-lived tasks, allowing for more fine-grained scheduling.
	 * @return {@code true} if this executor prefers short-lived tasks (the default),
	 * {@code false} otherwise (for treatment like a regular {@code TaskExecutor})
	 */
	default boolean prefersShortLivedTasks() {
		return true;
	}

}