1 /* 2 * Copyright (c) 2010, 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 6913877 26 * @summary Stress AsynchronousFileChannel.write 27 */ 28 29 import java.io.*; 30 import java.nio.ByteBuffer; 31 import static java.nio.file.StandardOpenOption.*; 32 import java.nio.channels.*; 33 import java.util.Random; 34 import java.util.concurrent.CountDownLatch; 35 36 public class LotsOfWrites { 37 static final Random rand = new Random(); 38 39 /** 40 * Asynchronously writes a known pattern to a file up to a given size, 41 * counting down a latch to release waiters when done. 42 */ 43 static class Writer implements CompletionHandler<Integer,ByteBuffer> { 44 private final File file; 45 private final long size; 46 private final CountDownLatch latch; 47 private final AsynchronousFileChannel channel; 48 49 private volatile long position; 50 private volatile byte nextByte; 51 52 private long updatePosition(long nwrote) { 53 position += nwrote; 54 return position; 55 } 56 57 private ByteBuffer genNextBuffer() { 58 int n = Math.min(8192 + rand.nextInt(8192), (int)(size - position)); 59 ByteBuffer buf = ByteBuffer.allocate(n); 60 for (int i=0; i<n; i++) { 61 buf.put(nextByte++); 62 } 63 buf.flip(); 64 return buf; 65 } 66 67 // close channel and release any waiters 68 private void done() { 69 try { 70 channel.close(); 71 } catch (IOException ignore) { } 72 latch.countDown(); 73 } 74 75 Writer(File file, long size, CountDownLatch latch) throws IOException { 76 this.file = file; 77 this.size = size; 78 this.latch = latch; 79 this.channel = AsynchronousFileChannel.open(file.toPath(), WRITE); 80 } 81 82 File file() { 83 return file; 84 } 85 86 long size() { 87 return size; 88 } 89 90 // initiate first write 91 void start() { 92 ByteBuffer buf = genNextBuffer(); 93 channel.write(buf, 0L, buf, this); 94 } 95 96 @Override 97 public void completed(Integer nwrote, ByteBuffer buf) { 98 long pos = updatePosition(nwrote); 99 if (!buf.hasRemaining()) { 100 // buffer has been completely written; decide if we need to 101 // write more 102 if (position >= size) { 103 done(); 104 return; 105 } 106 buf = genNextBuffer(); 107 } 108 channel.write(buf, pos, buf, this); 109 } 110 111 @Override 112 public void failed(Throwable exc, ByteBuffer buf) { 113 exc.printStackTrace(); 114 done(); 115 } 116 } 117 118 public static void main(String[] args) throws Exception { 119 // random number of writers 120 int count = 20 + rand.nextInt(16); 121 Writer[] writers = new Writer[count]; 122 CountDownLatch latch = new CountDownLatch(count); 123 124 // initiate writing to each file 125 for (int i=0; i<count; i++) { 126 long size = 512*1024 + rand.nextInt(512*1024); 127 File blah = File.createTempFile("blah", null); 128 blah.deleteOnExit(); 129 Writer writer = new Writer(blah, size, latch); 130 writers[i] = writer; 131 writer.start(); 132 } 133 134 // wait for writing to complete 135 latch.await(); 136 137 // verify content of each file 138 boolean failed = false; 139 byte[] buf = new byte[8192]; 140 for (int i=0; i<count ;i++) { 141 Writer writer = writers[i]; 142 FileInputStream in = new FileInputStream(writer.file()); 143 try { 144 long size = 0L; 145 byte expected = 0; 146 int nread = in.read(buf); 147 while (nread > 0) { 148 for (int j=0; j<nread; j++) { 149 if (buf[j] != expected) { 150 System.err.println("Unexpected contents"); 151 failed = true; 152 break; 153 } 154 expected++; 155 } 156 if (failed) 157 break; 158 size += nread; 159 nread = in.read(buf); 160 } 161 if (!failed && size != writer.size()) { 162 System.err.println("Unexpected size"); 163 failed = true; 164 } 165 if (failed) 166 break; 167 } finally { 168 in.close(); 169 } 170 } 171 172 // clean-up 173 for (int i=0; i<count; i++) { 174 writers[i].file().delete(); 175 } 176 177 if (failed) 178 throw new RuntimeException("Test failed"); 179 } 180 }