1 /* 2 * Copyright (c) 2003, 2020, 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 * @requires os.family == "Linux" 26 * @bug 4863423 27 * @summary Test Util caching policy 28 */ 29 30 import java.io.*; 31 import java.nio.*; 32 import java.nio.channels.*; 33 34 public class BigReadWrite { 35 36 static int testSize = 15; 37 38 public static void main(String[] args) throws Exception { 39 FileOutputStream fos = new FileOutputStream("/dev/zero"); 40 FileChannel fc = fos.getChannel(); 41 42 // Three small writes to fill up the Util cache 43 ByteBuffer buf = ByteBuffer.allocate(900); 44 fc.write(buf); 45 buf = ByteBuffer.allocate(950); 46 fc.write(buf); 47 buf = ByteBuffer.allocate(975); 48 fc.write(buf); 49 buf = ByteBuffer.allocate(4419000); 50 51 // Now initiate large write to create larger direct buffers 52 long iterations = 0; 53 while (iterations < 50) { 54 fc.write(buf); 55 buf.rewind(); 56 iterations++; 57 } 58 // Clean up 59 fc.close(); 60 } 61 }