RFR: 8220657: JFR.dump does not work when filename is set

[Yasumasa Suenaga]

Hi,

Do you have concern(s) about this change?

>>>    http://cr.openjdk.java.net/~ysuenaga/JDK-8220657/webrev.01/

As in the email below, I think it does not affect scenarios except snapshot cloning.
Please tell me if you have any opinions about this.


Thanks,

Yasumasa


On 2019/03/20 10:37, Yasumasa Suenaga wrote:
> Hi Erik,
> 
> I think this change does not affect other scenarios.
> 
> :jdk_jfr jtreg tests and submit repo have passed with this change.
> newSnapshotClone() is called by PlatformRecording::dump and
> DCmdDump::newSnapshot.
> Both methods are related to user-requested dump.
> 
> What scenarios do you think? I want to check them.
> 
> 
> Thanks,
> 
> Yasumasa
> 
> 
> 2019年3月19日(火) 23:59 Erik Gahlin <erik.gahlin at oracle.com>:
>>
>> Yes, but then you would lose the original destination in other scenarios
>>
>> Maybe I can look at this next week.
>>
>> Erik
>>
>>> Hi Erik,
>>>
>>> Thank you for your reply.
>>>
>>> How about this changeset?
>>>
>>>    http://cr.openjdk.java.net/~ysuenaga/JDK-8220657/webrev.01/
>>>
>>> I think PlatformRecording#newSnapshotClone() should not dump.
>>> So I removed `setDestination()` from this.
>>>
>>>
>>> Yasumasa
>>>
>>>
>>> On 2019/03/19 22:04, Erik Gahlin wrote:
>>>> This looks a bit hackish.
>>>>
>>>> The real issue seems to be that the method
>>>> PlatformRecording#newSnapshotClone incorrectly sets the destination in
>>>> the clone, which then triggers a dump prematurely (when stop is called).
>>>>
>>>> Purpose of that method is just to take a snapshot of existing chunks in
>>>> the disk repository (or from memory). and then let dumpStopped(path) do
>>>> the actual dump (copy out the data from the disk repository).
>>>>
>>>> To make it work, some other changes would be needed as well, but I don't
>>>> have time to investigate.
>>>>
>>>> Erik
>>>>
>>>>> Hi all,
>>>>>
>>>>> Please review this change.
>>>>>
>>>>>      JBS: https://bugs.openjdk.java.net/browse/JDK-8220657
>>>>>      webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8220657/webrev.00/
>>>>>
>>>>> The user might not get flight record via JFR.dump if JFR is started
>>>>> with filename option on target process.
>>>>>
>>>>> Please see JBS if you want to know how to reproduce.
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Yasumasa
>>