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

[srikalyan chandrashekar]

Hi David, yes thats right, only benefit i see is we can avoid assignment 
to 'r' if pending is null.

--
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
>>>>>
>>>