SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.runtime.midlet;

import java.util.LinkedList;
import java.util.Queue;

/**
 * This manages the cleanup of MIDlet related methods.
 *
 * @since 2020/07/03
 */
public final class CleanupHandler
{
    /** Queue of handles waiting to be closed. */
    private static final Queue<AutoCloseable> _QUEUE =
        new LinkedList<>();
    
    /**
     * Not used.
     * 
     * @since 2020/07/03
     */
    private CleanupHandler()
    {
    }
    
    /**
     * Adds a task to be called when the MIDlet exits.
     * 
     * @param __task The task to add.
     * @throws NullPointerException On null arguments.
     * @since 2020/07/03
     */
    public static void add(AutoCloseable __task)
        throws NullPointerException
    {
        if (__task == null)
            throw new NullPointerException("NARG");
        
        synchronized (CleanupHandler.class)
        {
            CleanupHandler._QUEUE.add(__task);
        }
    }
    
    /**
     * Runs all of the cleanup handlers and drains from the queue.
     * 
     * @since 2020/07/03
     */
    public static void runAll()
    {
        // Clear out the queue and drain everything to an array
        AutoCloseable[] drain;
        synchronized (CleanupHandler.class)
        {
            Queue<AutoCloseable> queue = CleanupHandler._QUEUE;
            drain = queue.<AutoCloseable>toArray(
                new AutoCloseable[queue.size()]);
            queue.clear();
        }
        
        // Close all those items now
        for (AutoCloseable closing : drain)
            try
            {
                closing.close();
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
    }
}