1 /* 2 * Copyright (c) 2014, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import sun.hotspot.WhiteBox; 25 26 class AllocateBeyondMetaspaceSize { 27 public static Object dummy; 28 29 public static void main(String [] args) { 30 if (args.length != 2) { 31 throw new IllegalArgumentException("Usage: <MetaspaceSize> <YoungGenSize>"); 32 } 33 34 long metaspaceSize = Long.parseLong(args[0]); 35 long youngGenSize = Long.parseLong(args[1]); 36 37 run(metaspaceSize, youngGenSize); 38 } 39 40 private static void run(long metaspaceSize, long youngGenSize) { 41 WhiteBox wb = WhiteBox.getWhiteBox(); 42 43 long allocationBeyondMetaspaceSize = metaspaceSize * 2; 44 long metaspace = wb.allocateMetaspace(null, allocationBeyondMetaspaceSize); 45 46 triggerYoungGC(youngGenSize); 47 48 wb.freeMetaspace(null, metaspace, metaspace); 49 } 50 51 private static void triggerYoungGC(long youngGenSize) { 52 long approxAllocSize = 32 * 1024; 53 long numAllocations = 2 * youngGenSize / approxAllocSize; 54 55 for (long i = 0; i < numAllocations; i++) { 56 dummy = new byte[(int)approxAllocSize]; 57 } 58 } 59 }