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/*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/* @test
* @bug 6913877
* @summary Stress AsynchronousFileChannel.write
* @key randomness
*/
import java.io.*;
import java.nio.ByteBuffer;
import static java.nio.file.StandardOpenOption.*;
import java.nio.channels.*;
import java.util.Random;
import java.util.concurrent.CountDownLatch;
public class LotsOfWrites {
static final Random rand = new Random();
/**
* Asynchronously writes a known pattern to a file up to a given size,
* counting down a latch to release waiters when done.
*/
static class Writer implements CompletionHandler<Integer,ByteBuffer> {
private final File file;
private final long size;
private final CountDownLatch latch;
private final AsynchronousFileChannel channel;
private volatile long position;
private volatile byte nextByte;
private long updatePosition(long nwrote) {
position += nwrote;
return position;
}
private ByteBuffer genNextBuffer() {
int n = Math.min(8192 + rand.nextInt(8192), (int)(size - position));
ByteBuffer buf = ByteBuffer.allocate(n);
for (int i=0; i<n; i++) {
buf.put(nextByte++);
}
buf.flip();
return buf;
}
// close channel and release any waiters
private void done() {
try {
channel.close();
} catch (IOException ignore) { }
latch.countDown();
}
Writer(File file, long size, CountDownLatch latch) throws IOException {
this.file = file;
this.size = size;
this.latch = latch;
this.channel = AsynchronousFileChannel.open(file.toPath(), WRITE);
}
File file() {
return file;
}
long size() {
return size;
}
// initiate first write
void start() {
ByteBuffer buf = genNextBuffer();
channel.write(buf, 0L, buf, this);
}
@Override
public void completed(Integer nwrote, ByteBuffer buf) {
long pos = updatePosition(nwrote);
if (!buf.hasRemaining()) {
// buffer has been completely written; decide if we need to
// write more
if (position >= size) {
done();
return;
}
buf = genNextBuffer();
}
channel.write(buf, pos, buf, this);
}
@Override
public void failed(Throwable exc, ByteBuffer buf) {
exc.printStackTrace();
done();
}
}
public static void main(String[] args) throws Exception {
// random number of writers
int count = 20 + rand.nextInt(16);
Writer[] writers = new Writer[count];
CountDownLatch latch = new CountDownLatch(count);
// initiate writing to each file
for (int i=0; i<count; i++) {
long size = 512*1024 + rand.nextInt(512*1024);
File blah = File.createTempFile("blah", null);
blah.deleteOnExit();
Writer writer = new Writer(blah, size, latch);
writers[i] = writer;
writer.start();
}
// wait for writing to complete
latch.await();
// verify content of each file
boolean failed = false;
byte[] buf = new byte[8192];
for (int i=0; i<count ;i++) {
Writer writer = writers[i];
FileInputStream in = new FileInputStream(writer.file());
try {
long size = 0L;
byte expected = 0;
int nread = in.read(buf);
while (nread > 0) {
for (int j=0; j<nread; j++) {
if (buf[j] != expected) {
System.err.println("Unexpected contents");
failed = true;
break;
}
expected++;
}
if (failed)
break;
size += nread;
nread = in.read(buf);
}
if (!failed && size != writer.size()) {
System.err.println("Unexpected size");
failed = true;
}
if (failed)
break;
} finally {
in.close();
}
}
// clean-up
for (int i=0; i<count; i++) {
writers[i].file().delete();
}
if (failed)
throw new RuntimeException("Test failed");
}
}
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