org.eclipse.jetty.util.thread.PrivilegedThreadFactory Maven / Gradle / Ivy

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// 
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// 
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// 
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// 
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
// 
package org.eclipse.jetty.util.thread;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.function.Supplier;

/**
 *  Convenience class to ensure that a new Thread is created
 *  inside a privileged block.
 *
 *  This prevents the Thread constructor
 *  from pinning the caller's context classloader. This happens
 *  when the Thread constructor takes a snapshot of the current
 *  calling context - which contains ProtectionDomains that may
 *  reference the context classloader - and remembers it for the
 *  lifetime of the Thread.
 *
 * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
 */
@Deprecated(since = "2021-05-27")
class PrivilegedThreadFactory {

    /**
     * Use a Supplier to make a new thread, calling it within
     * a privileged block to prevent classloader pinning.
     *
     * @param newThreadSupplier a Supplier to create a fresh thread
     * @return a new thread, protected from classloader pinning.
     */
    static  T newThread(Supplier newThreadSupplier) {
        return AccessController.doPrivileged(new PrivilegedAction() {

            @Override
            public T run() {
                return newThreadSupplier.get();
            }
        });
    }
}