RFR: JDK-8208473: [TESTBUG] nsk/jdb/exclude/exclude001/exclude001.java is timing out on solaris-sparc again

[Gary Adams]

Speaking of not being bullet proof, during testing of the fix to
wait for a specific prompt an intermittent failure was observed.
...

Sending command: trace methods 0x2a9
reply[0]: MyThread-0[1]
Sending command: cont
WARNING: message not recieved: MyThread-0[1]
Remaining debugger output follows:
reply[0]:>
reply[1]: Method exited: return value =<void value>, "thread=MyThread-0", nsk.jdb.exclude.exclude001.MyThread.run(), line=93 bci=14
reply[2]: 93        }
reply[3]:
reply[4]: MyThread-0[1]
# ERROR: Caught unexpected exception while executing the test: nsk.share.Failure: Expected message not received during 420200 milliseconds:
...

The wait for message times out looking for "MyThread-0[1]".
A WARNING is printed and the "remaining debugger output"
shows that "MyThread-0[1]" is in the buffer.

I'm still investigating why the message match is not found.

Adding a final check before failing the wait for message
seems to workaround the problem.

diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/jdb/Jdb.java 
b/test/hotspot/jtreg/vmTestbase/nsk/share/jdb/Jdb.java
--- a/test/hotspot/jtreg/vmTestbase/nsk/share/jdb/Jdb.java
+++ b/test/hotspot/jtreg/vmTestbase/nsk/share/jdb/Jdb.java
@@ -515,10 +515,11 @@
          long delta = 200; // time in milliseconds to wait at every 
iteration.
          long total = 0;    // total time has waited.
          long max = getLauncher().getJdbArgumentHandler().getWaitTime() 
* 60 * 1000;  // maximum time to wait.
+        int found = 0;

          Object dummy = new Object();
          while ((total += delta) <= max) {
-            int found = 0;
+            found = 0;

              // search for message
              {
@@ -553,6 +554,12 @@
          log.display("WARNING: message not recieved: " + message);
          log.display("Remaining debugger output follows:");
          receiveReply(startPos);
+
+        // One last chance
+        found = findMessage(startPos, message);
+        if (found > 0) {
+            return found;
+        }
          throw new Failure("Expected message not received during " + 
total + " milliseconds:"
                              + "\n\t" + message);
      }


On 9/20/18, 5:47 PM, Chris Plummer wrote:
> Looks good. Still not bullet proof, but I'm not sure it's possible to 
> write tests like this in a way that will work no matter what output is 
> produced by the method enter/exit events.
>
> Chris
>
> On 9/20/18 10:59 AM, Gary Adams wrote:
>> The test failure has been identified due to the "int[2]"
>> being misrecognized as a compound prompt.  This caused a cont
>> command to be sent prematurely.
>>
>> The proposed fix waits for the correct prompt before
>> advancing to the next command.
>>
>>   Webrev: http://cr.openjdk.java.net/~gadams/8208473/webrev/
>>   Issue: https://bugs.openjdk.java.net/browse/JDK-8208473
>>
>> Testing is in progress.
>
>
>