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/*
* Copyright (c) 2013, 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 8024833
* @key intermittent
* @summary Tests interruption of threads mapping sections of a file channel in
* an attempt to deadlock due to nesting of begin calls.
*/
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.nio.channels.FileChannel.MapMode;
import java.nio.file.*;
import java.util.concurrent.Semaphore;
import static java.nio.file.StandardOpenOption.*;
public class InterruptMapDeadlock {
static class Mapper extends Thread {
final FileChannel fc;
final Semaphore gate;
volatile Exception exception;
Mapper(FileChannel fc, Semaphore gate) {
this.fc = fc;
this.gate = gate;
}
@Override
public void run() {
try {
gate.acquireUninterruptibly();
fc.map(MapMode.READ_ONLY, 0, 1);
throw new Exception("Map succeeded");
} catch (IOException x) {
System.out.println(x.getClass() + " (expected)");
} catch (Exception unexpected) {
this.exception = unexpected;
}
}
Exception exception() {
return exception;
}
static Mapper startMapper(FileChannel fc, Semaphore gate) {
Mapper r = new Mapper(fc, gate);
r.setDaemon(true);
r.start();
return r;
}
}
static class Interruptor extends Thread {
final Mapper[] mappers;
final Semaphore gate;
Interruptor(Mapper[] mappers, Semaphore gate) {
this.mappers = mappers;
this.gate = gate;
}
public void run() {
gate.release(mappers.length);
for (Mapper m : mappers) {
m.interrupt();
}
}
}
// the number of mapper threads to start
private static final int MAPPER_COUNT = 4;
public static void main(String[] args) throws Exception {
Path file = Paths.get("data.txt");
FileChannel.open(file, CREATE, TRUNCATE_EXISTING, WRITE).close();
Mapper[] mappers = new Mapper[MAPPER_COUNT];
for (int i=1; i<=20; i++) {
System.out.format("Iteration: %s%n", i);
FileChannel fc = FileChannel.open(file);
boolean failed = false;
Semaphore gate = new Semaphore(0);
// start mapper threads
for (int j=0; j<MAPPER_COUNT; j++) {
mappers[j] = Mapper.startMapper(fc, gate);
}
// interrupt and wait for the mappers to terminate
Interruptor interruptor = new Interruptor(mappers, gate);
interruptor.start();
try {
interruptor.join(10000);
if (interruptor.isAlive()) {
System.err.println("Interruptor thread did not terminate:");
Throwable t = new Exception("Stack trace");
t.setStackTrace(interruptor.getStackTrace());
t.printStackTrace();
failed = true;
}
} catch (InterruptedException x) {
System.err.println("Main thread was interrupted");
failed = true;
}
for (Mapper m: mappers) {
try {
m.join(10000);
Exception e = m.exception();
if (e != null) {
System.err.println("Mapper thread failed with: " + e);
failed = true;
} else if (m.isAlive()) {
System.err.println("Mapper thread did not terminate:");
Throwable t = new Exception("Stack trace");
t.setStackTrace(m.getStackTrace());
t.printStackTrace();
failed = true;
}
} catch (InterruptedException x) {
System.err.println("Main thread was interrupted");
failed = true;
}
}
if (failed)
throw new RuntimeException("Test failed - see log for details");
else
fc.close();
}
}
}
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