/*
 * Copyright (c) 2015, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.jersey.spi;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadFactory;

import javax.annotation.PreDestroy;

Default implementation of the Jersey 
scheduled executor service provider SPI. 
 This provider creates and provisions a shared ScheduledThreadPoolExecutor instance using the customizable core threads, backing thread factory and rejected task handler values. Subclasses may override the respective methods to customize the parameters of the provisioned scheduler. 
 When Jersey runtime no longer requires the use of a provided executor service instance, it invokes the provider's dispose method to signal the provider that the executor service instance can be disposed of. In this method, provider is free to implement the proper shut-down logic for the disposed executor service instance and perform other necessary cleanup. Yet, some providers may wish to implement a shared executor service strategy. In such case, it may not be desirable to shut down the released executor service in the dispose method. Instead, to perform the eventual shut-down procedure, the provider may either rely on an explicit invocation of it's specific clean-up method. Since all Jersey providers operate in a container environment, a good clean-up strategy for a shared executor service provider implementation is to expose a @PreDestroy-annotated method that will be invoked for all instances managed by the container, before the container shuts down. 

IMPORTANT: Please note that any pre-destroy methods may not be invoked for instances created outside of the container
and later registered within the container. Pre-destroy methods are only guaranteed to be invoked for those instances
that are created and managed by the container.

Author:
Marek Potociar
Since:
2.18/**
 * Default implementation of the Jersey {@link org.glassfish.jersey.spi.ScheduledExecutorServiceProvider
 * scheduled executor service provider SPI}.
 * <p>
 * This provider creates and provisions a shared {@link java.util.concurrent.ScheduledThreadPoolExecutor} instance
 * using the customizable {@link #getCorePoolSize() core threads}, {@link #getBackingThreadFactory() backing thread factory}
 * and {@link #getRejectedExecutionHandler() rejected task handler} values. Subclasses may override the respective methods
 * to customize the parameters of the provisioned scheduler.
 * </p>
 * <p>
 * When Jersey runtime no longer requires the use of a provided executor service instance, it invokes the provider's
 * {@link #dispose} method to signal the provider that the executor service instance can be disposed of. In this method,
 * provider is free to implement the proper shut-down logic for the disposed executor service instance and perform other
 * necessary cleanup. Yet, some providers may wish to implement a shared executor service strategy. In such case,
 * it may not be desirable to shut down the released executor service in the {@link #dispose} method. Instead, to perform the
 * eventual shut-down procedure, the provider may either rely on an explicit invocation of it's specific clean-up method.
 * Since all Jersey providers operate in a <em>container</em> environment, a good clean-up strategy for a shared executor
 * service provider implementation is to expose a {@link javax.annotation.PreDestroy &#64;PreDestroy}-annotated method
 * that will be invoked for all instances managed by the container, before the container shuts down.
 * </p>
 * <p>
 * IMPORTANT: Please note that any pre-destroy methods may not be invoked for instances created outside of the container
 * and later registered within the container. Pre-destroy methods are only guaranteed to be invoked for those instances
 * that are created and managed by the container.
 * </p>
 *
 * @author Marek Potociar
 * @since 2.18
 */
public class ScheduledThreadPoolExecutorProvider extends AbstractThreadPoolProvider<ScheduledThreadPoolExecutor>
        implements ScheduledExecutorServiceProvider {

    
Create a new instance of the scheduled thread pool executor provider.
Params:
name – provider name. The name will be used to name the threads created & used by the
            provisioned scheduled thread pool executor./**
     * Create a new instance of the scheduled thread pool executor provider.
     *
     * @param name provider name. The name will be used to name the threads created & used by the
     *             provisioned scheduled thread pool executor.
     */
    public ScheduledThreadPoolExecutorProvider(final String name) {
        super(name);
    }

    @Override
    public ScheduledExecutorService getExecutorService() {
        return super.getExecutor();
    }

    @Override
    protected ScheduledThreadPoolExecutor createExecutor(
            final int corePoolSize, final ThreadFactory threadFactory, final RejectedExecutionHandler handler) {
        return new ScheduledThreadPoolExecutor(corePoolSize, threadFactory, handler);
    }

    @Override
    public void dispose(final ExecutorService executorService) {
        // NO-OP.
    }

    
Container pre-destroy handler method.
 Invoking the method closes this provider. 
/**
     * Container pre-destroy handler method.
     * <p>
     * Invoking the method {@link #close() closes} this provider.
     * </p>
     */
    @PreDestroy
    public void preDestroy() {
        close();
    }

}