| /* |
| * Copyright (c) 2019, 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. |
| * |
| * 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. |
| */ |
| |
| /* |
| * @test |
| * @bug 8209824 |
| * @summary per latest JDK code coverage report, 2 methods replaceStaleEntry |
| * and prevIndex in ThreadLocal.ThreadLocalMap are not touched |
| * by any JDK regression tests, this is to trigger the code paths. |
| * @modules java.base/java.lang:+open |
| * @run testng ReplaceStaleEntry |
| */ |
| |
| import java.lang.reflect.Field; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import static org.testng.Assert.assertEquals; |
| import org.testng.annotations.BeforeClass; |
| import org.testng.annotations.Test; |
| |
| public class ReplaceStaleEntry { |
| |
| public static int INITIAL_CAPACITY; |
| |
| @BeforeClass |
| public static void setup() throws Exception { |
| Class<?> clazz = Class.forName("java.lang.ThreadLocal$ThreadLocalMap"); |
| Field f = clazz.getDeclaredField("INITIAL_CAPACITY"); |
| f.setAccessible(true); |
| INITIAL_CAPACITY = f.getInt(null); |
| System.out.println("INITIAL_CAPACITY: " + INITIAL_CAPACITY); |
| } |
| |
| /** |
| * This test triggers the code path to replaceStaleEntry, so as prevIndex is |
| * triggered too as it's called by replaceStaleEntry. |
| * The code paths must be triggered by reusing an already used entry in the |
| * map's entry table. The code below |
| * 1. first occupies the entries |
| * 2. then expunges the entries by removing strong references to thread locals |
| * 3. then reuse some of entries by adding more thread locals to the thread |
| * and, the above steps are run for several times by adding more and more |
| * thread locals, also trigger rehash of the map. |
| */ |
| @Test |
| public static void test() { |
| Map<Integer, ThreadLocal> locals = new HashMap<>(); |
| for (int j = 1; j < 32; j *= 2) { |
| int loop = INITIAL_CAPACITY * j; |
| for (int i = 0; i < loop; i++) { |
| ThreadLocal l = new ThreadLocal<Integer>(); |
| l.set(i); |
| locals.put(i, l); |
| } |
| locals.keySet().stream().forEach(i -> { |
| assertEquals((int)locals.get(i).get(), (int)i, "Unexpected thread local value!"); |
| }); |
| locals.clear(); |
| System.gc(); |
| } |
| } |
| } |