svn commit: r1466253 - /hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java

[todd]

Author: todd
Date: Tue Apr  9 21:34:12 2013
New Revision: 1466253

URL: http://svn.apache.org/r1466253
Log:
HDFS-4643. Fix flakiness in TestQuorumJournalManager. Contributed by Todd 
Lipcon.

Modified:
    
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java

Modified: 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java
URL: 
http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java?rev=1466253&r1=1466252&r2=1466253&view=diff
==============================================================================
--- 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java
 (original)
+++ 
hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java
 Tue Apr  9 21:34:12 2013
@@ -20,6 +20,9 @@ package org.apache.hadoop.test;
 import java.io.File;
 import java.io.IOException;
 import java.io.StringWriter;
+import java.lang.management.ManagementFactory;
+import java.lang.management.ThreadInfo;
+import java.lang.management.ThreadMXBean;
 import java.lang.reflect.InvocationTargetException;
 import java.util.Arrays;
 import java.util.Random;
@@ -340,4 +343,23 @@ public abstract class GenericTestUtils {
     Assert.assertTrue("Expected " + actual + " to be in range (" + expectedMin 
+ ","
         + expectedMax + ")", expectedMin <= actual && actual <= expectedMax);
   }
+
+  /**
+   * Assert that there are no threads running whose name matches the
+   * given regular expression.
+   * @param regex the regex to match against
+   */
+  public static void assertNoThreadsMatching(String regex) {
+    Pattern pattern = Pattern.compile(regex);
+    ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
+    
+    ThreadInfo[] infos = 
threadBean.getThreadInfo(threadBean.getAllThreadIds(), 20);
+    for (ThreadInfo info : infos) {
+      if (info == null) continue;
+      if (pattern.matcher(info.getThreadName()).matches()) {
+        Assert.fail("Leaked thread: " + info + "\n" +
+            Joiner.on("\n").join(info.getStackTrace()));
+      }
+    }
+  }
 }