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/*
* Copyright (c) 2016, 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 8148192
* @summary Invoking close asynchronously can cause register to fail with
* an IOException rather than a ClosedWatchServiceException
* @run main LotsOfCloses
*/
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.file.ClosedWatchServiceException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchService;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class LotsOfCloses {
private static final Random RAND = new Random();
public static void main(String[] args) throws Exception {
Path dir = Files.createTempDirectory("tmp");
ExecutorService pool = Executors.newCachedThreadPool();
try {
// run the test repeatedly
long start = System.currentTimeMillis();
while ((System.currentTimeMillis() - start) < 5000) {
test(dir, pool);
}
} finally {
pool.shutdown();
}
}
/**
* Create a WatchService to watch for changes in the given directory
* and then attempt to close the WatchService and change a registration
* at the same time.
*/
static void test(Path dir, ExecutorService pool) throws Exception {
WatchService watcher = FileSystems.getDefault().newWatchService();
// initial registration
dir.register(watcher, StandardWatchEventKinds.ENTRY_CREATE);
// submit tasks to close the WatchService and update the registration
Future<Void> closeResult;
Future<Boolean> registerResult;
if (RAND.nextBoolean()) {
closeResult = pool.submit(newCloserTask(watcher));
registerResult = pool.submit(newRegisterTask(watcher, dir));
} else {
registerResult = pool.submit(newRegisterTask(watcher, dir));
closeResult = pool.submit(newCloserTask(watcher));
}
closeResult.get();
registerResult.get();
}
/**
* Returns a task that closes the given WatchService.
*/
static Callable<Void> newCloserTask(WatchService watcher) {
return () -> {
try {
watcher.close();
return null;
} catch (IOException ioe) {
throw new UncheckedIOException(ioe);
}
};
}
/**
* Returns a task that updates the registration of a directory with
* a WatchService.
*/
static Callable<Boolean> newRegisterTask(WatchService watcher, Path dir) {
return () -> {
try {
dir.register(watcher, StandardWatchEventKinds.ENTRY_DELETE);
return true;
} catch (ClosedWatchServiceException e) {
return false;
} catch (IOException ioe) {
throw new UncheckedIOException(ioe);
}
};
}
}
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