1 /*

     2  * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package sun.misc;

    27 

    28 /**

    29  * A thread that has it's thread locals, and inheritable thread

    30  * locals erased on construction.

    31  */

    32 public class ManagedLocalsThread extends Thread {

    33     private static final jdk.internal.misc.Unsafe UNSAFE;

    34     private static final long THREAD_LOCALS;

    35     private static final long INHERITABLE_THREAD_LOCALS;

    36 

    37     public ManagedLocalsThread() {

    38         eraseThreadLocals();

    39     }

    40 

    41     public ManagedLocalsThread(Runnable target) {

    42         super(target);

    43         eraseThreadLocals();

    44     }

    45 

    46     public ManagedLocalsThread(String name) {

    47         super(name);

    48         eraseThreadLocals();

    49     }

    50 

    51     public ManagedLocalsThread(ThreadGroup group, Runnable target) {

    52         super(group, target);

    53         eraseThreadLocals();

    54     }

    55 

    56     public ManagedLocalsThread(Runnable target, String name) {

    57         super(target, name);

    58         eraseThreadLocals();

    59     }

    60 

    61     public ManagedLocalsThread(ThreadGroup group, String name) {

    62         super(group, name);

    63         eraseThreadLocals();

    64     }

    65 

    66     public ManagedLocalsThread(ThreadGroup group, Runnable target, String name) {

    67         super(group, target, name);

    68         eraseThreadLocals();

    69     }

    70 

    71     /**

    72      * Drops all thread locals (and inherited thread locals).

    73      */

    74     public final void eraseThreadLocals() {

    75         UNSAFE.putObject(this, THREAD_LOCALS, null);

    76         UNSAFE.putObject(this, INHERITABLE_THREAD_LOCALS, null);

    77     }

    78 

    79     static {

    80         UNSAFE = jdk.internal.misc.Unsafe.getUnsafe();

    81         Class<?> t = Thread.class;

    82         try {

    83             THREAD_LOCALS = UNSAFE.objectFieldOffset

    84                 (t.getDeclaredField("threadLocals"));

    85             INHERITABLE_THREAD_LOCALS = UNSAFE.objectFieldOffset

    86                 (t.getDeclaredField("inheritableThreadLocals"));

    87         } catch (Exception e) {

    88             throw new Error(e);

    89         }

    90     }

    91 }

    92