1 /* 2 * Copyright (c) 2016, Red Hat, Inc. and/or its affiliates. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 /* 24 * @test TestHumongous 25 * @summary test reclaim of humongous object 26 * @run main/othervm -Xint -XX:+UseShenandoahGC -XX:ShenandoahHeapRegionSize=1M TestHumongous 27 */ 28 29 public class TestHumongous { 30 // Shenandoah heap memory region size = 1 M 31 private static int M = 1024 * 1024; 32 public static void main(String[] args) { 33 // Construct a humongous object (oop) just fits multiple regions 34 // 8 bytes for object header, 8 bytes for brooks pointer 35 int size = 2 * M - 8 - 8; 36 // The oop spans 2 regions 37 char[] ch = new char[size]; 38 for (int index = 0; index < 10; index ++) { 39 ch[index] = 'A'; 40 } 41 42 System.out.print(ch[1]); 43 ch = null; 44 // Force a GC to clean up above object 45 System.gc(); 46 } 47 } 48