54 lines
1.9 KiB
Java
54 lines
1.9 KiB
Java
/*
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* Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/*
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* @test
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* @bug 6387919
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* @summary Confirm ThreadLocal.set() usage is not a side effect of get()
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* @author Pete Soper
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*/
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public class ImmutableLocal
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{
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/**
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* {@link ThreadLocal} guaranteed to always return the same reference.
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*/
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public abstract static class ImmutableThreadLocal extends ThreadLocal {
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public void set(final Object value) {
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throw new RuntimeException("ImmutableThreadLocal set called");
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}
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// force override
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protected abstract Object initialValue();
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}
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private static final ThreadLocal cache = new ImmutableThreadLocal() {
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public Object initialValue() {
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return Thread.currentThread().getName();
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}
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};
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public static void main(final String[] args) {
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System.out.println("cache.get() = " + cache.get());
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}
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}
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