1 /* 2 * Copyright (c) 2003, 2011, 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 /* @test 25 * @bug 4802340 26 * @summary Testing force(), load() isLoaded() of zero len MBB 27 * @run main/othervm ZeroMap 28 * @key randomness 29 */ 30 31 import java.io.*; 32 import java.nio.*; 33 import java.util.*; 34 import java.nio.channels.*; 35 36 public class ZeroMap { 37 public static void main(String[] args) throws Exception { 38 Random random = new Random(); 39 long filesize = random.nextInt(1024*1024); 40 int cut = random.nextInt((int)filesize); 41 File file = File.createTempFile("Blah", null); 42 file.deleteOnExit(); 43 try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) { 44 raf.setLength(filesize); 45 FileChannel fc = raf.getChannel(); 46 MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_WRITE, cut, 0); 47 mbb.force(); 48 mbb.load(); 49 mbb.isLoaded(); 50 } 51 52 // improve chance that mapped buffer will be unmapped 53 System.gc(); 54 Thread.sleep(500); 55 } 56 }