/* * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * 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). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.rmi.runtime; import java.security.AccessController;import java.security.PrivilegedAction;import sun.security.util.SecurityConstants; /** * A PrivilegedAction for creating a new thread conveniently with an * AccessController.doPrivileged construct. * * All constructors allow the choice of the Runnable for the new * thread to execute, the name of the new thread (which will be * prefixed with "RMI "), and whether or not it will be a daemon * thread. * * The new thread may be created in the system thread group (the root * of the thread group tree) or an internally created non-system * thread group, as specified at construction of this class. * * The new thread will have the system class loader as its initial * context class loader (that is, its context class loader will NOT be * inherited from the current thread). * * @author      Peter Jones **/public final class NewThreadAction implements PrivilegedAction<Thread> {     /** cached reference to the system (root) thread group */    static final ThreadGroup systemThreadGroup =        AccessController.doPrivileged(new PrivilegedAction<ThreadGroup>() {            public ThreadGroup run() {                ThreadGroup group = Thread.currentThread().getThreadGroup();                ThreadGroup parent;                while ((parent = group.getParent()) != null) {                    group = parent;                }                return group;            }        });     /**     * special child of the system thread group for running tasks that     * may execute user code, so that the security policy for threads in     * the system thread group will not apply     */    static final ThreadGroup userThreadGroup =        AccessController.doPrivileged(new PrivilegedAction<ThreadGroup>() {            public ThreadGroup run() {                return new ThreadGroup(systemThreadGroup, "RMI Runtime");            }        });     private final ThreadGroup group;    private final Runnable runnable;    private final String name;    private final boolean daemon;     NewThreadAction(ThreadGroup group, Runnable runnable,                    String name, boolean daemon)    {        this.group = group;        this.runnable = runnable;        this.name = name;        this.daemon = daemon;    }     /**     * Creates an action that will create a new thread in the     * system thread group.     *     * @param   runnable the Runnable for the new thread to execute     *     * @param   name the name of the new thread     *     * @param   daemon if true, new thread will be a daemon thread;     * if false, new thread will not be a daemon thread     */    public NewThreadAction(Runnable runnable, String name, boolean daemon) {        this(systemThreadGroup, runnable, name, daemon);    }     /**     * Creates an action that will create a new thread.     *     * @param   runnable the Runnable for the new thread to execute     *     * @param   name the name of the new thread     *     * @param   daemon if true, new thread will be a daemon thread;     * if false, new thread will not be a daemon thread     *     * @param   user if true, thread will be created in a non-system     * thread group; if false, thread will be created in the system     * thread group     */    public NewThreadAction(Runnable runnable, String name, boolean daemon,                           boolean user)    {        this(user ? userThreadGroup : systemThreadGroup,             runnable, name, daemon);    }     public Thread run() {        SecurityManager sm = System.getSecurityManager();        if (sm != null) {            sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);        }        Thread t = new Thread(group, runnable, "RMI " + name);        t.setContextClassLoader(ClassLoader.getSystemClassLoader());        t.setDaemon(daemon);        return t;    }}