merge -r 1357936:1357937 from trunk. FIXES: MAPREDUCE-4384

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1357940 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Thomas Graves 2012-07-05 21:37:53 +00:00
parent 9e4b5f52ea
commit ca78b62579
2 changed files with 23 additions and 15 deletions

View File

@ -514,6 +514,8 @@ Release 0.23.3 - UNRELEASED
MAPREDUCE-4392. Counters.makeCompactString() changed behavior from 0.20
(Jason Lowe via bobby)
MAPREDUCE-4384. Race conditions in IndexCache (Kihwal Lee via tgraves)
Release 0.23.2 - UNRELEASED
INCOMPATIBLE CHANGES

View File

@ -67,13 +67,13 @@ class IndexCache {
if (info == null) {
info = readIndexFileToCache(fileName, mapId, expectedIndexOwner);
} else {
synchronized (info) {
while (null == info.mapSpillRecord) {
try {
info.wait();
} catch (InterruptedException e) {
throw new IOException("Interrupted waiting for construction", e);
}
while (isUnderConstruction(info)) {
try {
// In case the entry is ready after the above check but
// before the following wait, we do timed wait.
info.wait(200);
} catch (InterruptedException e) {
throw new IOException("Interrupted waiting for construction", e);
}
}
LOG.debug("IndexCache HIT: MapId " + mapId + " found");
@ -88,6 +88,12 @@ class IndexCache {
return info.mapSpillRecord.getIndex(reduce);
}
private boolean isUnderConstruction(IndexInformation info) {
synchronized(info) {
return (null == info.mapSpillRecord);
}
}
private IndexInformation readIndexFileToCache(Path indexFileName,
String mapId,
String expectedIndexOwner)
@ -95,13 +101,13 @@ class IndexCache {
IndexInformation info;
IndexInformation newInd = new IndexInformation();
if ((info = cache.putIfAbsent(mapId, newInd)) != null) {
synchronized (info) {
while (null == info.mapSpillRecord) {
try {
info.wait();
} catch (InterruptedException e) {
throw new IOException("Interrupted waiting for construction", e);
}
while (isUnderConstruction(info)) {
try {
// In case the entry is ready after the above check but
// before the following wait, we do timed wait.
info.wait(200);
} catch (InterruptedException e) {
throw new IOException("Interrupted waiting for construction", e);
}
}
LOG.debug("IndexCache HIT: MapId " + mapId + " found");
@ -139,7 +145,7 @@ class IndexCache {
*/
public void removeMap(String mapId) {
IndexInformation info = cache.get(mapId);
if ((info != null) && (info.getSize() == 0)) {
if (info == null || ((info != null) && isUnderConstruction(info))) {
return;
}
info = cache.remove(mapId);