HADOOP-7166. Add DaemonFactory to common. Contributed by Erik Steffl and jitendra.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1080775 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -74,6 +74,8 @@ Trunk (unreleased changes)
     HADOOP-7133. Batch the calls in DataStorage to FileUtil.createHardLink().
     (Matt Foley via jghoman)
 
+    HADOOP-7166. Add DaemonFactory to common. (Erik Steffl & jitendra)
+
   OPTIMIZATIONS
 
   BUG FIXES

src/java/org/apache/hadoop/util/Daemon.java

@@ -18,6 +18,8 @@
 
 package org.apache.hadoop.util;
 
+import java.util.concurrent.ThreadFactory;
+
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 
@@ -30,6 +32,20 @@ public class Daemon extends Thread {
     setDaemon(true);                              // always a daemon
   }
 
+  /**
+   * Provide a factory for named daemon threads,
+   * for use in ExecutorServices constructors
+   */
+  @InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
+  public static class DaemonFactory extends Daemon implements ThreadFactory {
+
+    @Override
+    public Thread newThread(Runnable runnable) {
+      return new Daemon(runnable);
+    }
+
+  }
+
   Runnable runnable = null;
   /** Construct a daemon thread. */
   public Daemon() {