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/*
* Copyright (c) 2009, 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 6543863 6842687
* @summary Try to cause a deadlock between (Asynchronous)FileChannel.close
* and FileLock.release
*/
import java.io.*;
import java.nio.file.Path;
import static java.nio.file.StandardOpenOption.*;
import java.nio.channels.*;
import java.util.concurrent.*;
public class ReleaseOnCloseDeadlock {
private static final int LOCK_COUNT = 1024;
public static void main(String[] args) throws IOException {
File blah = File.createTempFile("blah", null);
blah.deleteOnExit();
try {
for (int i=0; i<100; i++) {
test(blah.toPath());
}
} finally {
blah.delete();
}
}
static void test(Path file) throws IOException {
FileLock[] locks = new FileLock[LOCK_COUNT];
FileChannel fc = FileChannel.open(file, READ, WRITE);
for (int i=0; i<LOCK_COUNT; i++) {
locks[i] = fc.lock(i, 1, true);
}
tryToDeadlock(fc, locks);
AsynchronousFileChannel ch = AsynchronousFileChannel.open(file, READ, WRITE);
for (int i=0; i<LOCK_COUNT; i++) {
try {
locks[i] = ch.lock(i, 1, true).get();
} catch (InterruptedException x) {
throw new RuntimeException(x);
} catch (ExecutionException x) {
throw new RuntimeException(x);
}
}
tryToDeadlock(ch, locks);
}
static void tryToDeadlock(final Channel channel, FileLock[] locks)
throws IOException
{
// start thread to close the file (and invalidate the locks)
Thread closer = new Thread(
new Runnable() {
public void run() {
try {
channel.close();
} catch (IOException ignore) {
ignore.printStackTrace();
}
}});
closer.start();
// release the locks explicitly
for (int i=0; i<locks.length; i++) {
try {
locks[i].release();
} catch (ClosedChannelException ignore) { }
}
// we are done when closer has terminated
while (closer.isAlive()) {
try {
closer.join();
} catch (InterruptedException ignore) { }
}
}
}
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