HADOOP-8894. GenericTestUtils.waitFor should dump thread stacks on timeout. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1395825 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -297,6 +297,9 @@ Release 2.0.3-alpha - Unreleased
     HADOOP-8804. Improve Web UIs when the wildcard address is used.
     (Senthil Kumar via eli)
 
+    HADOOP-8894. GenericTestUtils.waitFor should dump thread stacks on timeout
+    (todd)
+
   OPTIMIZATIONS
 
     HADOOP-8866. SampleQuantiles#query is O(N^2) instead of O(N). (Andrew Wang

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

@@ -104,7 +104,10 @@ public abstract class GenericTestUtils {
       
       Thread.sleep(checkEveryMillis);
     } while (Time.now() - st < waitForMillis);
-    throw new TimeoutException("Timed out waiting for condition");
+    
+    throw new TimeoutException("Timed out waiting for condition. " +
+        "Thread diagnostics:\n" +
+        TimedOutTestsListener.buildThreadDiagnosticString());
   }
   
   public static class LogCapturer {

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

@@ -58,18 +58,27 @@ public class TimedOutTestsListener extends RunListener {
         && failure.getMessage().startsWith(TEST_TIMED_OUT_PREFIX)) {
       output.println("====> TEST TIMED OUT. PRINTING THREAD DUMP. <====");
       output.println();
-      DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss,SSS");
-      output.println(String.format("Timestamp: %s", dateFormat.format(new Date())));
+      output.print(buildThreadDiagnosticString());
+    }
+  }
+  
+  public static String buildThreadDiagnosticString() {
+    StringWriter sw = new StringWriter();
+    PrintWriter output = new PrintWriter(sw);
+    
+    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss,SSS");
+    output.println(String.format("Timestamp: %s", dateFormat.format(new Date())));
+    output.println();
+    output.println(buildThreadDump());
+    
+    String deadlocksInfo = buildDeadlockInfo();
+    if (deadlocksInfo != null) {
+      output.println("====> DEADLOCKS DETECTED <====");
       output.println();
-      output.println(buildThreadDump());
-      
-      String deadlocksInfo = buildDeadlockInfo();
-      if (deadlocksInfo != null) {
-        output.println("====> DEADLOCKS DETECTED <====");
-        output.println();
-        output.println(deadlocksInfo);
-      }
+      output.println(deadlocksInfo);
     }
+
+    return sw.toString();
   }
 
   static String buildThreadDump() {