Analysis on JDK-8022321 java/lang/ref/OOMEInReferenceHandler.java fails intermittently

[David Holmes]

On 24/01/2014 11:53 AM, srikalyan chandrashekar wrote:
> Hi David, yes thats right, only benefit i see is we can avoid assignment
> to 'r' if pending is null.

I'm okay with either version.

David

> --
> Thanks
> kalyan
>
> On 1/23/14 4:33 PM, David Holmes wrote:
>> On 24/01/2014 6:10 AM, srikalyan wrote:
>>> Hi Peter, i have modified your code from
>>>
>>> r = pending;
>>> if (r != null) {
>>>       ......
>>>        TO
>>> if (pending != null) {
>>>       r = pending;
>>>
>>> This is because the r is used later in the code and must not be assigned
>>> pending unless it is not null(this was as is earlier).
>>
>> If r is null, because pending is null then you perform the wait() and
>> then continue - back to the top of the loop. There is no bug in
>> Peter's code.
>>
>> The new webrev is
>>> posted here
>>> http://cr.openjdk.java.net/~srikchan/Regression/JDK-8022321_OOMEInReferenceHandler-webrev-V2/
>>>
>>> . I ran a 1000 run and no failures so far, however i would like to run a
>>> couple more 1000 runs to assert the fix.
>>>
>>> PS: The description section of JEP-122
>>> (http://openjdk.java.net/jeps/122) says meta-data would be in native
>>> memory(not heap).
>>
>> The class_mirror is a Java object not meta-data.
>>
>> David
>>
>>> --
>>> Thanks
>>> kalyan
>>> Ph: (408)-585-8040
>>>
>>>
>>> On 1/21/14, 2:31 PM, Peter Levart wrote:
>>>>
>>>> On 01/21/2014 07:17 PM, srikalyan wrote:
>>>>> Hi Peter/David, catching up after long weekend. Why would there be an
>>>>> OOME in object heap due to class loading in perm gen space ?
>>>>
>>>> The perm gen is not a problem her (JDK 8 does not have it and we see
>>>> OOME on JDK8 too). Each time a class is loaded, new java.lang.Class
>>>> object is allocated on heap.
>>>>
>>>> Regards, Peter
>>>>
>>>>> Please correct if i am missing something here. Meanwhile i will give
>>>>> the version of Reference Handler you both agreed on a try.
>>>>> --
>>>>> Thanks
>>>>> kalyan
>>>>> Ph: (408)-585-8040
>>>>>
>>>>> On 1/21/14, 7:24 AM, Peter Levart wrote:
>>>>>> On 01/21/2014 07:54 AM, Peter Levart wrote:
>>>>>>> *[Loaded sun.misc.Cleaner from
>>>>>>> /home/peter/Apps64/jdk1.8.0-ea-b121/jre/lib/rt.jar]*
>>>>>>> [Loaded java.io.ByteArrayInputStream from
>>>>>>> /home/peter/Apps64/jdk1.8.0-ea-b121/jre/lib/rt.jar]
>>>>>>> [Loaded sun.util.calendar.ZoneInfoFile$ZoneOffsetTransitionRule
>>>>>>> from /home/peter/Apps64/jdk1.8.0-ea-b121/jre/lib/rt.jar]
>>>>>>> ...
>>>>>>>
>>>>>>>
>>>>>>> I'm on linux, 64bit and using official EA build 121 of JDK 8...
>>>>>>>
>>>>>>> But if I try with JDK 7u45, I don't see it.
>>>>>>
>>>>>> So what changed between JDK 7 and JDK 8?
>>>>>>
>>>>>> I suspect the following: 8007572: Replace existing jdk timezone data
>>>>>> at <java.home>/lib/zi with JSR310's tzdb
>>>>>>
>>>>>>
>>>>>> Regards, Peter
>>>>>>
>>>>
>