1 /* 2 * Copyright (c) 2002, 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 4625907 26 * @summary Testing force() 27 * @run main/othervm Force 28 */ 29 30 import java.io.*; 31 import java.nio.*; 32 import java.util.*; 33 import java.nio.channels.*; 34 35 public class Force { 36 public static void main(String[] args) throws Exception { 37 Random random = new Random(); 38 long filesize = random.nextInt(3*1024*1024); 39 int cut = random.nextInt((int)filesize); 40 File file = File.createTempFile("Blah", null); 41 file.deleteOnExit(); 42 try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) { 43 raf.setLength(filesize); 44 FileChannel fc = raf.getChannel(); 45 MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_WRITE, cut, filesize-cut); 46 mbb.force(); 47 } 48 49 // improve chance that mapped buffer will be unmapped 50 System.gc(); 51 Thread.sleep(500); 52 } 53 }