99 lines
3.4 KiB
Java
99 lines
3.4 KiB
Java
/*
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* Copyright (c) 2015, 2021, 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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import sun.hotspot.WhiteBox;
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public class LockStringTest extends Thread {
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static String lock;
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static boolean done;
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static WhiteBox wb = WhiteBox.getWhiteBox();
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public static void main(String[] args) throws Exception {
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if (!wb.areSharedStringsMapped()) {
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System.out.println("The shared strings are not mapped");
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System.out.println("LockStringTest: PASS");
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return;
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}
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if (!wb.isSharedClass(LockStringTest.class)) {
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throw new RuntimeException("Failed: LockStringTest class is not shared.");
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}
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// Note: This class is archived. All string literals (including the ones used in this class)
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// in all archived classes are interned into the CDS shared string table.
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doTest("StringLock", false);
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doTest("", true);
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// The following string has a 0 hashCode. Calling String.hashCode() could cause
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// the String.hash field to be written into, if so make sure we don't functionally
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// break.
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doTest("\u0121\u0151\u00a2\u0001\u0001\udbb2", true);
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}
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private static void doTest(String s, boolean hasZeroHashCode) throws Exception {
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lock = s;
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done = false;
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if (!wb.isSharedInternedString(lock)) {
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throw new RuntimeException("Failed: String \"" + lock + "\" is not shared.");
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}
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if (hasZeroHashCode && lock.hashCode() != 0) {
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throw new RuntimeException("Shared string \"" + lock + "\" should have 0 hashCode, but is instead " + lock.hashCode());
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}
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String copy = new String(lock);
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if (lock.hashCode() != copy.hashCode()) {
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throw new RuntimeException("Shared string \"" + lock + "\" does not have the same hashCode as its non-shared copy");
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}
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new LockStringTest().start();
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synchronized(lock) {
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while (!done) {
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lock.wait();
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}
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}
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System.gc();
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System.out.println("LockStringTest: PASS");
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}
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public void run() {
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String shared = "LiveOak";
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synchronized (lock) {
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for (int i = 0; i < 100; i++) {
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new String(shared);
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System.gc();
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try {
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sleep(5);
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} catch (InterruptedException e) {}
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}
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done = true;
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lock.notify();
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}
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}
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}
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