MAPREDUCE-4194. ConcurrentModificationError in DirectoryCollection (Jonathan Eagles via bobby)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1330552 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Robert Joseph Evans 2012-04-25 20:49:41 +00:00
parent 3b773da036
commit 719b719e3d
3 changed files with 80 additions and 16 deletions

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@ -406,6 +406,9 @@ Release 0.23.3 - UNRELEASED
MAPREDUCE-4133. MR over viewfs is broken (John George via bobby)
MAPREDUCE-4194. ConcurrentModificationError in DirectoryCollection
(Jonathan Eagles via bobby)
Release 0.23.2 - UNRELEASED
INCOMPATIBLE CHANGES

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@ -19,10 +19,9 @@
package org.apache.hadoop.yarn.server.nodemanager;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.Collections;
import java.util.List;
import java.util.ListIterator;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
@ -41,23 +40,22 @@ class DirectoryCollection {
private int numFailures;
public DirectoryCollection(String[] dirs) {
localDirs = new ArrayList<String>();
localDirs.addAll(Arrays.asList(dirs));
failedDirs = new ArrayList<String>();
localDirs = new CopyOnWriteArrayList<String>(dirs);
failedDirs = new CopyOnWriteArrayList<String>();
}
/**
* @return the current valid directories
*/
synchronized List<String> getGoodDirs() {
return localDirs;
return Collections.unmodifiableList(localDirs);
}
/**
* @return the failed directories
*/
synchronized List<String> getFailedDirs() {
return failedDirs;
return Collections.unmodifiableList(failedDirs);
}
/**
@ -75,22 +73,17 @@ synchronized int getNumFailures() {
*/
synchronized boolean checkDirs() {
int oldNumFailures = numFailures;
ListIterator<String> it = localDirs.listIterator();
while (it.hasNext()) {
final String dir = it.next();
for (final String dir : localDirs) {
try {
DiskChecker.checkDir(new File(dir));
} catch (DiskErrorException de) {
LOG.warn("Directory " + dir + " error " +
de.getMessage() + ", removing from the list of valid directories.");
it.remove();
localDirs.remove(dir);
failedDirs.add(dir);
numFailures++;
}
}
if (numFailures > oldNumFailures) {
return true;
}
return false;
return numFailures > oldNumFailures;
}
}

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@ -0,0 +1,68 @@
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.yarn.server.nodemanager;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.ListIterator;
import org.apache.hadoop.fs.FileUtil;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
public class TestDirectoryCollection {
private static final File testDir = new File("target",
TestDirectoryCollection.class.getName()).getAbsoluteFile();
private static final File testFile = new File(testDir, "testfile");
@BeforeClass
public static void setup() throws IOException {
testDir.mkdirs();
testFile.createNewFile();
}
@AfterClass
public static void teardown() {
FileUtil.fullyDelete(testDir);
}
@Test
public void testConcurrentAccess() throws IOException {
// Initialize DirectoryCollection with a file instead of a directory
String[] dirs = {testFile.getPath()};
DirectoryCollection dc = new DirectoryCollection(dirs);
// Create an iterator before checkDirs is called to reliable test case
List<String> list = dc.getGoodDirs();
ListIterator<String> li = list.listIterator();
// DiskErrorException will invalidate iterator of non-concurrent
// collections. ConcurrentModificationException will be thrown upon next
// use of the iterator.
Assert.assertTrue("checkDirs did not remove test file from directory list",
dc.checkDirs());
// Verify no ConcurrentModification is thrown
li.next();
}
}