1 /* 2 * Copyright (c) 2018, 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 * @test 27 * @bug 8196869 28 * @summary Make sure we deal with internal Key data being cleared properly 29 * @run main/othervm -Xms16m -Xmx16m -esa SoftKeys 30 * @ignore This test aims to provoke NPEs, but due to the need to constrain 31 * memory usage it fails intermittently with OOME on various systems 32 * with no way to ignore such failures. 33 */ 34 import java.util.*; 35 36 public class SoftKeys { 37 38 private static final char[] CHARS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; 39 40 public static void main(String[] args) { 41 try { 42 // With 4 characters in "language", we'll fill up a 16M heap quickly, 43 // causing full GCs and SoftReference reclamation. Repeat at least two 44 // times to verify no NPEs appear when looking up Locale's whose 45 // softly referenced data in sun.util.locale.BaseLocale$Key might have 46 // been cleared. 47 for (int i = 0; i < 2; i++) { 48 for (int j = 0; j < 512*1024; j++) { 49 new Locale(langForInt(j), "", ""); 50 } 51 } 52 } catch (OutOfMemoryError e) { 53 // Can happen on some system configurations, and while increasing heap 54 // size would allow GC to keep up, it also makes it impractically hard 55 // to reproduce NPE issues that could arise when references are being 56 // cleared. 57 58 // Do a System.gc() to not throw an OOME again in the jtreg wrapper. 59 System.gc(); 60 } 61 } 62 63 private static String langForInt(int val) { 64 StringBuilder buf = new StringBuilder(4); 65 buf.append(CHARS[(val >> 12) & 0xF]); 66 buf.append(CHARS[(val >> 8) & 0xF]); 67 buf.append(CHARS[(val >> 4) & 0xF]); 68 buf.append(CHARS[(val >> 0) & 0xF]); 69 return buf.toString(); 70 } 71 } 72