infernap12/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2026-04-22 21:00:31 +00:00
Code Issues Packages Projects Releases Wiki Activity

8166253: (ch) FileLock object can get GC'd and result in unexpected release of file lock

Browse Source 
Reviewed-by: alanb, dfuchs, mli, rriggs
This commit is contained in:
Brian Burkhalter 2018-02-02 13:44:26 -08:00
parent 0b8689b331
commit 073cfe14a5
2 changed files with 155 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
src/java.base/share/classes/sun/nio/ch/FileLockTable.java
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2005, 2018, 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
@ -115,9 +115,13 @@ class SharedFileLockTable extends FileLockTable {
// File key for the file that this channel is connected to
private final FileKey fileKey;
// Locks obtained for this channel
private final Set<FileLock> locks;
SharedFileLockTable(Channel channel, FileDescriptor fd) throws IOException {
this.channel = channel;
this.fileKey = FileKey.create(fd);
this.locks = new HashSet<FileLock>();
}
@Override
@ -135,6 +139,7 @@ class SharedFileLockTable extends FileLockTable {
if (prev == null) {
// we successfully created the key so we add the file lock
list.add(new FileLockReference(fl, queue, fileKey));
locks.add(fl);
break;
}
}
@ -151,6 +156,7 @@ class SharedFileLockTable extends FileLockTable {
if (list == current) {
checkList(list, fl.position(), fl.size());
list.add(new FileLockReference(fl, queue, fileKey));
locks.add(fl);
break;
}
list = current;
@ -187,6 +193,7 @@ class SharedFileLockTable extends FileLockTable {
assert (lock != null) && (lock.acquiredBy() == channel);
ref.clear();
list.remove(index);
locks.remove(fl);
break;
}
index++;
@ -220,6 +227,8 @@ class SharedFileLockTable extends FileLockTable {
// once the lock list is empty we remove it from the map
removeKeyIfEmpty(fileKey, list);
locks.clear();
}
}
return result;
@ -238,6 +247,8 @@ class SharedFileLockTable extends FileLockTable {
if (lock == fromLock) {
ref.clear();
list.set(index, new FileLockReference(toLock, queue, fileKey));
locks.remove(fromLock);
locks.add(toLock);
break;
}
}

143
test/jdk/java/nio/channels/FileLock/FileLockGC.java Normal file
View File

@ -0,0 +1,143 @@
/*
* Copyright (c) 2018, 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.
*/
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import java.nio.channels.FileLock;
import java.nio.channels.OverlappingFileLockException;
import java.nio.file.Files;
import java.nio.file.Path;
import jdk.test.lib.util.FileUtils;
/*
* @test
* @bug 8166253
* @summary Verify that OverlappingFileLockException is thrown when expected.
* @library .. /test/lib
* @build jdk.test.lib.util.FileUtils
* @run main/othervm FileLockGC
*/
public class FileLockGC {
public enum TestType {
NO_GC_NO_RELEASE(true),
// A hypothetical 'GC_THEN_RELEASE' case is infeasible
RELEASE(false),
RELEASE_THEN_GC(false),
GC(true);
private final boolean exceptionExpected;
TestType(boolean exceptionExpected) {
this.exceptionExpected = exceptionExpected;
}
boolean exceptionExpected() {
return exceptionExpected;
}
}
public static void main(String[] args) throws Exception {
final File f = new File(System.getProperty("test.dir", ".")
+ File.separator + "junk.txt");
final Path p = f.toPath();
int failures = 0;
for (TestType t : TestType.values()) {
try {
if (!testFileLockGC(f, t)) {
failures++;
}
} finally {
FileUtils.deleteFileIfExistsWithRetry(p);
}
}
if (failures != 0) {
throw new RuntimeException("Test had " + failures + " failure(s)");
}
}
private static boolean testFileLockGC(File f, TestType type)
throws InterruptedException, IOException {
System.out.printf("Test %s starting%n", type.toString());
final RandomAccessFile raf1 = new RandomAccessFile(f, "rw");
FileLock lock1 = raf1.getChannel().tryLock();
WeakReference<FileLock> ref1 = new WeakReference(lock1);
switch (type) {
case GC:
lock1 = null;
System.gc();
break;
case RELEASE:
lock1.release();
break;
case RELEASE_THEN_GC:
lock1.release();
lock1 = null;
System.gc();
break;
default: // NO_GC_NO_RELEASE
// lock1 is neither collected nor released
break;
}
final RandomAccessFile raf2 = new RandomAccessFile(f, "rw");
boolean success = true;
FileLock lock2 = null;
try {
lock2 = raf2.getChannel().tryLock();
if (type.exceptionExpected()) {
System.err.printf
("No expected OverlappingFileLockException for test %s%n",
type.toString());
success = false;
}
} catch (OverlappingFileLockException ofe) {
if (!type.exceptionExpected()) {
System.err.printf
("Unexpected OverlappingFileLockException for test %s%n",
type.toString());
success = false;
}
} finally {
if (lock1 != null) {
lock1.release();
}
if (lock2 != null) {
lock2.release();
}
raf2.close();
raf1.close();
System.out.printf("Test %s finished%n", type.toString());
}
return success;
}
}