RFR (XXXS) 8173693 disable post_class_unload() for non JavaThread initiators

[Daniel D. Daugherty]

Jerry,

Thanks for the fast review!

Dan


On 1/31/17 11:36 AM, Gerald Thornbrugh wrote:
> Hi Dan,
>
> Your changes look good.
>
> Thanks,
>
> Jerry
>> On Jan 31, 2017, at 10:18 AM, Daniel D. Daugherty <daniel.daugherty at oracle.com> wrote:
>>
>> Greetings,
>>
>> I have a very small work around for a JVM/TI event posting bug:
>>
>>     JDK-8173693 disable post_class_unload() for non JavaThread initiators
>>     https://bugs.openjdk.java.net/browse/JDK-8173693
>>
>> This work around disables the JVM/TI post_class_unload() function
>> when the thread requesting the event is not a JavaThread. See:
>>
>>     JDK-8173658 JvmtiExport::post_class_unload() is broken for non-JavaThread initiators
>>     https://bugs.openjdk.java.net/browse/JDK-8173658
>>
>> for the gory details of what can (and has) gone wrong.
>>
>> Fixing JDK-8173658 is non-trivial so this work around is proposed
>> to avoid allowing a Class Unload event to crash the VM or silently
>> corrupt the non JavaThread that tried to post the event.
>>
>> Webrev URL: http://cr.openjdk.java.net/~dcubed/8173693-webrev/0-jdk9-hs/
>>
>> Testing: Oracle internal VM/NSK JVM/TI test suite
>>          JPRT testing (in progress)
>>
>>
>> Thanks, in advance, for any comments, questions or suggestions.
>>
>> Dan