RFR(S): 8203664: JFR start failure after AppCDS archive created with JFR StartFlightRecording

[Lois Foltan]

+1.  Looks good Calvin.
Lois

On 6/25/2018 2:33 PM, Calvin Cheung wrote:
> Hi Jiangli,
>
> Thanks for your quick review.
>
> I've created a release note subtask JDK-8205622 
> <https://bugs.openjdk.java.net/browse/JDK-8205622> and have added some 
> release notes there.
>
> thanks,
> Calvin
>
> On 6/25/18, 11:00 AM, Jiangli Zhou wrote:
>> Hi Calvin,
>>
>>> On Jun 25, 2018, at 10:15 AM, Calvin 
>>> Cheung<calvin.cheung at oracle.com>  wrote:
>>>
>>> After some off-list discussions, I've modified the change to disable 
>>> JFR and output a warning message during CDS dump time if JFR is 
>>> specified.
>>>
>>> webrev: http://cr.openjdk.java.net/~ccheung/8203664/webrev.01/
>>>
>>> warning message:
>>> Java HotSpot(TM) 64-Bit Server VM warning: JFR will be disabled 
>>> during CDS dumping
>> This seems to be ok. The behavior should be documented for CDS. If 
>> the change goes to JDK 11, then the release notes for JDK 11 needs to 
>> be updated.
>>
>> Thanks,
>> Jiangli
>>
>>> The change passed hs-tier[1,2,3] testing.
>>>
>>> thanks,
>>> Calvin
>>>
>>> On 6/20/18, 11:18 AM, Calvin Cheung wrote:
>>>> Corrected the bug id in the subject and also the link to webrev:
>>>>
>>>> http://cr.openjdk.java.net/~ccheung/8203664/webrev.00/
>>>>
>>>> (Note: 8203*6*64 instead of 8203*3*64)
>>>>
>>>> thanks,
>>>> Calvin
>>>>
>>>> On 6/20/2018 11:04 AM, Calvin Cheung wrote:
>>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8203664
>>>>>
>>>>> webrev: http://cr.openjdk.java.net/~ccheung/8203364/webrev.00/
>>>>>
>>>>> The bug is due to some classes are being redefined during JFR 
>>>>> startup. The proposed change is to handle redefined classes better 
>>>>> during dump time.
>>>>>
>>>>> Summary of changes:
>>>>>
>>>>> klassFactory.cpp:
>>>>>
>>>>>     Only do the following assert if a class hasn't been redefined:
>>>>>
>>>>>     244       assert(cached_class_file == NULL, "Sanity");
>>>>>
>>>>> classLoader.cpp:
>>>>>
>>>>>     include JFR classes which are loaded via 'JVM_DefineClass'
>>>>>
>>>>> dictionary.cpp:
>>>>>
>>>>>     during dumping, exclude classes which have been redefined.
>>>>>
>>>>>     Only very few classes are being redefined with JFR enabled 
>>>>> during dumping:
>>>>>
>>>>>     java/lang/Throwable
>>>>>     java/net/SocketOutputStream
>>>>>     java/net/SocketInputStream
>>>>>     sun/nio/ch/SocketChannelImpl
>>>>>     java/io/FileOutputStream
>>>>>     java/lang/Error
>>>>>     sun/nio/ch/FileChannelImpl
>>>>>     java/io/FileInputStream
>>>>>     java/io/RandomAccessFile
>>>>>
>>>>> The change passed hs-tier[1,2,3] testing.
>>>>>
>>>>> thanks,
>>>>>
>>>>> Calvin
>>>>>