HDFS-6433. Replace BytesMoved class with AtomicLong. Contributed by Benoy Antony.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1596742 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -575,6 +575,9 @@ Release 2.5.0 - UNRELEASED
     HDFS-6409. Fix typo in log message about NameNode layout version upgrade.
     (Chen He via cnauroth)
 
+    HDFS-6433. Replace BytesMoved class with AtomicLong.
+    (Benoy Antony via cnauroth)
+
 Release 2.4.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/balancer/Balancer.java

@@ -47,6 +47,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
+import java.util.concurrent.atomic.AtomicLong;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -365,7 +366,7 @@ public class Balancer {
         
         sendRequest(out);
         receiveResponse(in);
-        bytesMoved.inc(block.getNumBytes());
+        bytesMoved.addAndGet(block.getNumBytes());
         LOG.info("Successfully moved " + this);
       } catch (IOException e) {
         LOG.warn("Failed to move " + this + ": " + e.getMessage());
@@ -1111,17 +1112,7 @@ public class Balancer {
     return null;
   }
 
-  private static class BytesMoved {
-    private long bytesMoved = 0L;;
-    private synchronized void inc( long bytes ) {
-      bytesMoved += bytes;
-    }
-
-    private synchronized long get() {
-      return bytesMoved;
-    }
-  };
-  private final BytesMoved bytesMoved = new BytesMoved();
+  private final AtomicLong bytesMoved = new AtomicLong();
   
   /* Start a thread to dispatch block moves for each source. 
    * The thread selects blocks to move & sends request to proxy source to