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* 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.
*
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* questions.
*/
/* @test
* @bug 4429043 4493595 6332756 6709457 7146506
* @summary Test FileChannel file locking
*/
import java.io.*;
import java.nio.channels.*;
import static java.nio.file.StandardOpenOption.*;
/**
* Testing FileChannel's lock method.
*/
public class Lock {
public static void main(String[] args) throws Exception {
if (args.length == 2) {
attemptLock(args[1], args[0].equals("2"));
return;
} else if (args.length != 0) {
throw new RuntimeException("Wrong number of parameters.");
}
File blah = File.createTempFile("blah", null);
blah.deleteOnExit();
RandomAccessFile raf = new RandomAccessFile(blah, "rw");
raf.write(1);
raf.close();
test1(blah, "1");
test1(blah, "2");
test2(blah, true);
test2(blah, false);
test3(blah);
test4(blah);
}
/**
* Test mutual locking with other process
*/
static void test1(File blah, String str) throws Exception {
try (RandomAccessFile fis = new RandomAccessFile(blah, "rw")) {
FileChannel fc = fis.getChannel();
FileLock lock = null;
// grab the lock
if (str.equals("1")) {
lock = fc.lock(0, 10, false);
if (lock == null)
throw new RuntimeException("Lock should not return null");
try {
fc.lock(5, 10, false);
throw new RuntimeException("Overlapping locks allowed");
} catch (OverlappingFileLockException e) {} // correct result
}
// execute the tamperer
String command = System.getProperty("java.home") +
File.separator + "bin" + File.separator + "java";
String testClasses = System.getProperty("test.classes");
if (testClasses != null)
command += " -cp " + testClasses;
command += " Lock " + str + " " + blah;
Process p = Runtime.getRuntime().exec(command);
// evaluate System.out of child process
String s;
boolean hasOutput = false;
InputStreamReader isr;
isr = new InputStreamReader(p.getInputStream());
BufferedReader br = new BufferedReader(isr);
while ((s = br.readLine()) != null) {
// only throw on Unix as windows over NFS fails...
if ((File.separatorChar == '/') && !s.equals("good")) {
throw new RuntimeException("Failed: " + s);
}
hasOutput = true;
}
// evaluate System.err in case of System.out of child process
// was empty
if (!hasOutput) {
isr = new InputStreamReader(p.getErrorStream());
br = new BufferedReader(isr);
if ((s = br.readLine()) != null) {
System.err.println("Error output:");
System.err.println(s);
while ((s = br.readLine()) != null) {
System.err.println(s);
}
}
throw new RuntimeException("Failed, no output");
}
// clean up, check multiple releases
if (lock != null) {
lock.release();
lock.release();
}
}
}
/**
* Basic test for FileChannel.lock() and FileChannel.tryLock()
*/
static void test2(File blah, boolean b) throws Exception {
try (RandomAccessFile raf = new RandomAccessFile(blah, "rw")) {
FileChannel channel = raf.getChannel();
FileLock lock;
if (b)
lock = channel.lock();
else
lock = channel.tryLock();
lock.release();
}
}
/**
* Test that overlapping file locking is not possible when using different
* FileChannel objects to the same file path
*/
static void test3(File blah) throws Exception {
try (RandomAccessFile raf1 = new RandomAccessFile(blah, "rw");
RandomAccessFile raf2 = new RandomAccessFile(blah, "rw"))
{
FileChannel fc1 = raf1.getChannel();
FileChannel fc2 = raf2.getChannel();
// lock via one channel, and then attempt to lock the same file
// using a second channel
FileLock fl1 = fc1.lock();
try {
fc2.tryLock();
throw new RuntimeException("Overlapping locks allowed");
} catch (OverlappingFileLockException x) {}
try {
fc2.lock();
throw new RuntimeException("Overlapping locks allowed");
} catch (OverlappingFileLockException x) {}
// release lock and the attempt to lock with the second channel
// should succeed.
fl1.release();
fc2.lock();
try {
fc1.lock();
throw new RuntimeException("Overlapping locks allowed");
} catch (OverlappingFileLockException x) {}
}
}
/**
* Test file locking when file is opened for append
*/
static void test4(File blah) throws Exception {
try (FileOutputStream fos = new FileOutputStream(blah, true)) {
FileChannel fc = fos.getChannel();
fc.tryLock().release();
fc.tryLock(0L, 1L, false).release();
fc.lock().release();
fc.lock(0L, 1L, false).release();
}
try (FileChannel fc = FileChannel.open(blah.toPath(), APPEND)) {
fc.tryLock().release();
fc.tryLock(0L, 1L, false).release();
fc.lock().release();
fc.lock(0L, 1L, false).release();
}
}
/**
* Utility method to be run in secondary process which tries to acquire a
* lock on a FileChannel
*/
static void attemptLock(String fileName,
boolean expectsLock) throws Exception
{
File f = new File(fileName);
try (RandomAccessFile raf = new RandomAccessFile(f, "rw")) {
FileChannel fc = raf.getChannel();
if (fc.tryLock(10, 10, false) == null) {
System.out.println("bad: Failed to grab adjacent lock");
}
if (fc.tryLock(0, 10, false) == null) {
if (expectsLock)
System.out.println("bad");
else
System.out.println("good");
} else {
if (expectsLock)
System.out.println("good");
else
System.out.println("bad");
}
}
}
}