RFR(S): 8246493: JDI stress/serial/mixed002 needs to use WhiteBox.deflateIdleMonitors support

[serguei.spitsyn at oracle.com]

+1

Thanks,
Serguei


On 6/29/20 12:49, Chris Plummer wrote:
> Looks good.
>
> Chris
>
> On 6/29/20 12:45 PM, Daniel D. Daugherty wrote:
>> Chris and Serguei,
>>
>> Thanks for the fast reviews!!
>>
>> I generated the webrev in my "mach5" directory and that was baselined
>> on the jdk-16+3 snapshot and that doesn't include the ProblemList 
>> change.
>> Sigh...  I have updated the repo to "current" and regenerated the 
>> webrev.
>>
>> test/hotspot/jtreg/ProblemList.txt  now shows:
>>
>> @@ -126,11 +126,10 @@
>>  vmTestbase/nsk/monitoring/ThreadMXBean/ThreadInfo/Deadlock/JavaDeadlock001/TestDescription.java 
>> 8060733 generic-all
>>
>>  vmTestbase/nsk/jdi/ThreadReference/stop/stop001/TestDescription.java 
>> 7034630 generic-all
>>  vmTestbase/nsk/jdi/VirtualMachine/redefineClasses/redefineclasses021/TestDescription.java 
>> 8065773 generic-all
>>  vmTestbase/nsk/jdi/VirtualMachine/redefineClasses/redefineclasses023/TestDescription.java 
>> 8065773 generic-all
>> -vmTestbase/nsk/jdi/stress/serial/mixed002/TestDescription.java 
>> 8246493 generic-all
>>
>>  vmTestbase/nsk/jdb/eval/eval001/eval001.java 8221503 generic-all
>>
>>  vmTestbase/metaspace/gc/firstGC_10m/TestDescription.java 8208250 
>> generic-all
>>  vmTestbase/metaspace/gc/firstGC_50m/TestDescription.java 8208250 
>> generic-all
>>
>> Thanks again for the fast reviews!!
>>
>> Dan
>>
>>
>> On 6/29/20 3:41 PM, serguei.spitsyn at oracle.com wrote:
>>> Hi Dan,
>>>
>>> The same as from Chris.
>>> The ProblemList.txt has no changes.
>>> Otherwise, it looks good.
>>>
>>> Thanks,
>>> Serguei
>>>
>>>
>>>
>>> On 6/29/20 12:37, Chris Plummer wrote:
>>>> Hi Dan,
>>>>
>>>> Something is wrong with ProblemList.txt. It doesn't show any 
>>>> changes, but I also don't see mixed002 in the file anymore.
>>>>
>>>> Otherwise the changes look good.
>>>>
>>>> thanks,
>>>>
>>>> Chris
>>>>
>>>> On 6/29/20 12:21 PM, Daniel D. Daugherty wrote:
>>>>> Greetings,
>>>>>
>>>>> I have a fix for the following bug:
>>>>>
>>>>>     JDK-8246493 JDI stress/serial/mixed002 needs to use 
>>>>> WhiteBox.deflateIdleMonitors support
>>>>>     https://bugs.openjdk.java.net/browse/JDK-8246493
>>>>>
>>>>> Here's the webrev URL:
>>>>>
>>>>> http://cr.openjdk.java.net/~dcubed/8246493-webrev/0_for_jdk16/
>>>>>
>>>>> The test bug that's being fixed:
>>>>>
>>>>> vmTestbase/nsk/jdi/stress/serial/mixed002/TestDescription.java fails
>>>>>     intermittently with the following message:
>>>>>
>>>>>      nsk.share.TestBug: There are more than one(2) instance of 
>>>>> 'nsk.share.jpda.StateTestThread in debuggee
>>>>>
>>>>> Summary of the fix:
>>>>>
>>>>>     Use WhiteBox.deflateIdleMonitors() to make sure that all inflated
>>>>>     ObjectMonitors are deflated after each debuggee has been run.
>>>>>
>>>>> This fix has been tested with a Mach5 Tier5 test run that executes 
>>>>> all
>>>>> of the JDI tests (along with JDWP, JVM/TI and other Serviceability 
>>>>> tests).
>>>>> I also did five 100 iteration runs of the failing mix002 test. 
>>>>> Each Mach5
>>>>> job set ran the test 100 times on Linux-X64, macOSX, and Win-X64 
>>>>> for a
>>>>> total of (5 * 100 * 3) iterations of 
>>>>> nsk/jdi/stress/serial/mixed002. There
>>>>> were no failures.
>>>>>
>>>>> Thanks, in advance, for any comments, questions or suggestions.
>>>>>
>>>>> Dan
>>>>>
>>>>>
>>>>> Gory details:
>>>>>
>>>>> The primary focus of the fix is in the first three files in the 
>>>>> webrev:
>>>>>
>>>>> test/hotspot/jtreg/vmTestbase/nsk/share/jdi/SerialExecutionDebuggee.java 
>>>>>
>>>>> test/hotspot/jtreg/vmTestbase/nsk/jdi/stress/serial/mixed002/TestDescription.java 
>>>>>
>>>>> test/hotspot/jtreg/ProblemList.txt
>>>>>
>>>>> nsk.share.jdi.SerialExecutionDebuggee is the class that used to 
>>>>> serially
>>>>> execute the debuggee portion of a specific list of tests. After 
>>>>> this class
>>>>> is done executing a debuggee class, it needs to deflate idle 
>>>>> monitors in
>>>>> order to prevent a StateTestThread object created by one debuggee 
>>>>> class
>>>>> from confusing the next debuggee class. Each of the debuggee 
>>>>> classes that
>>>>> use StateTestThread expect there to be only one of these objects. 
>>>>> However,
>>>>> since we are running multiple debuggee classes serially *in the 
>>>>> same VM*,
>>>>> the StateTestThread object created in one debuggee can still be 
>>>>> around
>>>>> when the next debuggee runs.
>>>>>
>>>>> The COMMAND_CLEAR_DEBUGGEE implementation clears the 
>>>>> currentDebuggee variable
>>>>> which permits the debuggee to be GC'ed and is modified by this fix 
>>>>> to call
>>>>> WhiteBox.deflateIdleMonitors() to make sure that all inflated 
>>>>> ObjectMonitors
>>>>> are deflated after each debuggee has been run. This takes care of 
>>>>> any pinned
>>>>> StateTestThread objects (and any other inflated ObjectMonitors).
>>>>>
>>>>>
>>>>> vmTestbase/nsk/jdi/stress/serial/mixed002 is a wrapper style 
>>>>> stress test that
>>>>> executes the debugger and debuggee parts of a specific list of 
>>>>> tests serially
>>>>> *in the same VM*. Several of the tests executed by mixed002 make 
>>>>> use of the
>>>>> StateTestThread class. The failure is intermittent because the 
>>>>> order of test
>>>>> execution is shuffled automatically and sometimes the 
>>>>> ServiceThread manages
>>>>> to execute deflation at the right time to prevent more than one 
>>>>> StateTestThread
>>>>> object from existing at the same time.
>>>>>
>>>>> The additions to vmTestbase/nsk/jdi/stress/serial/mixed002 are the 
>>>>> standard
>>>>> boilerplate needed to call WhiteBox functions from test code. The 
>>>>> actual call
>>>>> to WhiteBox.deflateIdleMonitors() is made in 
>>>>> SerialExecutionDebuggee. I did
>>>>> attempt a fix where I modified the StateTestThread class to make 
>>>>> the call to
>>>>> WhiteBox.deflateIdleMonitors() after the internal waitOnObject is 
>>>>> no longer
>>>>> contended or waited on. That fix reduced the frequency of the 
>>>>> failures by
>>>>> about half, but it didn't solve the test bug entirely. So I had to 
>>>>> make the
>>>>> fix in SerialExecutionDebuggee instead.
>>>>>
>>>>>
>>>>> test/hotspot/jtreg/ProblemList.txt is modified to re-enable the 
>>>>> mix002 test.
>>>>>
>>>>>
>>>>> The remaining nine files are also wrapper style stress tests that 
>>>>> execute
>>>>> the debugger and debuggee parts of a specific list of tests 
>>>>> serially *in
>>>>> the same VM*. Because these tests also use 
>>>>> SerialExecutionDebuggee, they
>>>>> also need the boilerplate changes so that 
>>>>> WhiteBox.deflateIdleMonitors()
>>>>> can be called.
>>>>
>>>>
>>>
>>
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