RFR(XS): 8212220 add code to verify results to metaspace/stressDictionary/StressDictionary.java

[Daniel D. Daugherty]

Greetings,

The following test has been timing out intermittently in the
jdk/jdk CI lately:

     vmTestbase/metaspace/stressDictionary/StressDictionary.java

Those failures are being tracked by the following bug:

     JDK-8211211 
vmTestbase/metaspace/stressDictionary/StressDictionary.java timeout
     https://bugs.openjdk.java.net/browse/JDK-8211211

While investigating the timeouts, I noticed that the test is not doing
explicit verification of the results from the ExecutorService so I have
added code to do that.

With the fix for JDK-8212028 in place, the test is timing out much more
frequently in the jdk/jdk CI; the total timeout for the test went from
20 minutes down to 8 minutes. I have changed the default timeout value
for the test to 5 minutes (from 2 minutes) and with the new default
TIMEOUT_FACTOR of 4 (was 10), the total timeout for the test will be
restored to 20 minutes.

The total timeout changes will allow the new results verification code
to be used in the infrequent 20 minute timeout cases that we originally
saw when JDK-8211211 was filed.

Here's the URL for the test changes:

http://cr.openjdk.java.net/~dcubed/8212220-webrev/0-for-jdk-jdk/

Here's the sub-task bug ID for the test changes:

     JDK-8212220 add code to verify results to 
metaspace/stressDictionary/StressDictionary.java
     https://bugs.openjdk.java.net/browse/JDK-8212220

I'm currently running the revised test thru the Mach5 system:

     builds-tier1,jdk-tier1,jdk-tier2,hs-tier1,hs-tier2,hs-tier3

It's a bit of overkill, but I don't know how much of the timeout
is being caused by test system load so I'm trying to replicate
what is being done by the jdk/jdk CI system.

Thanks, in advance, for any comments, questions or suggestions.

Dan.