MAPREDUCE-4467. IndexCache failures due to missing synchronization (Kihwal Lee via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1365240 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -749,6 +749,9 @@ Release 0.23.3 - UNRELEASED
     maximum-am-resource-percent configurable on a per queue basis (tgraves via
     bobby)
 
+    MAPREDUCE-4467. IndexCache failures due to missing synchronization
+    (Kihwal Lee via tgraves)
+
 Release 0.23.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/IndexCache.java

@@ -67,13 +67,13 @@ class IndexCache {
     if (info == null) {
       info = readIndexFileToCache(fileName, mapId, expectedIndexOwner);
     } else {
-      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);
+      synchronized(info) {
+        while (isUnderConstruction(info)) {
+          try {
+            info.wait();
+          } catch (InterruptedException e) {
+            throw new IOException("Interrupted waiting for construction", e);
+          }
         }
       }
       LOG.debug("IndexCache HIT: MapId " + mapId + " found");
@@ -101,13 +101,13 @@ class IndexCache {
     IndexInformation info;
     IndexInformation newInd = new IndexInformation();
     if ((info = cache.putIfAbsent(mapId, newInd)) != null) {
-      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);
+      synchronized(info) {
+        while (isUnderConstruction(info)) {
+          try {
+            info.wait();
+          } catch (InterruptedException e) {
+            throw new IOException("Interrupted waiting for construction", e);
+          }
         }
       }
       LOG.debug("IndexCache HIT: MapId " + mapId + " found");