CleanerFactory.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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package jdk.internal.ref;

import jdk.internal.misc.InnocuousThread;

import java.lang.ref.Cleaner;
import java.util.concurrent.ThreadFactory;

/**
 * CleanerFactory provides a Cleaner for use within system modules.
 * The cleaner is created on the first reference to the CleanerFactory.
 */
public final class CleanerFactory {

    /* The common Cleaner. */
    private static final Cleaner commonCleaner = Cleaner.create(new ThreadFactory() {
        @Override
        public Thread newThread(Runnable r) {
            return InnocuousThread.newSystemThread("Common-Cleaner",
                    r, Thread.MAX_PRIORITY - 2);
        }
    });

    /**
     * Cleaner for use within system modules.
     *
     * This Cleaner will run on a thread whose context class loader
     * is {@code null}. The system cleaning action to perform in
     * this Cleaner should handle a {@code null} context class loader.
     *
     * @return a Cleaner for use within system modules
     */
    public static Cleaner cleaner() {
        return commonCleaner;
    }
}