HBASE-19986 If HBaseTestClassRule timesout a test, thread dump

hbase-common/src/test/java/org/apache/hadoop/hbase/HBaseClassTestRule.java

@@ -1,4 +1,4 @@
-/**
+/*
  * 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
@@ -18,6 +18,7 @@
 package org.apache.hadoop.hbase;
 
 import java.util.concurrent.TimeUnit;
+
 import org.apache.hadoop.hbase.testclassification.LargeTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.SmallTests;

hbase-common/src/test/java/org/apache/hadoop/hbase/TestTimeout.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.hbase;
 
 import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.apache.hadoop.hbase.util.Threads;
 import org.junit.ClassRule;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -41,6 +42,18 @@ public class TestTimeout {
      */
     @Ignore @Test
     public void infiniteLoop() {
-        while (true) {}
+      // Launch a background non-daemon thread.
+      Thread t = new Thread("HangingThread") {
+        public void run() {
+          synchronized(this) {
+            while(true) {
+            }
+          }
+        }
+      };
+      t.start();
+      while (true) {
+        // Just hang out too.
+      }
    }
 }

hbase-common/src/test/java/org/apache/hadoop/hbase/TimedOutTestsListener.java

@@ -61,6 +61,7 @@ public class TimedOutTestsListener extends RunListener {
       output.println();
       output.print(buildThreadDiagnosticString());
     }
+    output.flush();
   }
   
   public static String buildThreadDiagnosticString() {

pom.xml

@@ -677,7 +677,7 @@
             <properties>
               <property>
                 <name>listener</name>
-                <value>org.apache.hadoop.hbase.HBaseClassTestRuleChecker,org.apache.hadoop.hbase.ResourceCheckerJUnitListener</value>
+                <value>org.apache.hadoop.hbase.TimedOutTestsListener,org.apache.hadoop.hbase.HBaseClassTestRuleChecker,org.apache.hadoop.hbase.ResourceCheckerJUnitListener</value>
               </property>
             </properties>
           </configuration>