RFR(S): 8163994: Nightly test crashed in jvmtiAllocate
chris.plummer at oracle.com
Mon Aug 29 06:43:30 UTC 2016
On 8/28/16 6:14 PM, David Holmes wrote:
> On 27/08/2016 7:35 AM, Chris Plummer wrote:
>> Hi Dmitry,
>> Although the fix is addressing the specific issue described in the bug,
>> what about the general issue of referencing gdata after a call to
>> cbEarlyVMDeath(). Do more references to gdata need to be protected?
>> Also, is there the possibility of a multi-threading race condition here?
>> Could gdata be cleared by another thread after it is checked?
> Certainly. This really isn't fixing anything just adding a bailout
> check before the crashing code. We can still crash and not be any the
> wiser as to why.
> Not sure I really see the point of doing this instead of closing this
> as a dup of JDK-8134103 and fixing things properly.
It it correct to say that Dmitry is fixing a bug exposed by JDK-8134103,
or that he is temporarily working around something that is not a true
bug, but is indirectly caused by JDK-8134103. I'm not sure, but the
answer will dictate the correct course of action here.
>> On 8/26/16 4:00 AM, Dmitry Samersoff wrote:
>>> Please review the fix.
>>> Under some circumstances, when JVMTI_ERROR_WRONG_PHASE(112) is
>>> jvmtiAllocate could be called after call to cbEarlyVMDeath.
>>> cbEarlyVMDeath set gdata->jvmti to NULL, so jvmtiAllocate crashes.
>>> The problem appears only once in nightly testing and I was not able to
>>> reproduce it locally.
>>> Guard added to jvmtiAllocate to get meaningful error message instead of
>>> These fix doesn't fix root cause - JVMTI_ERROR_WRONG_PHASE problem is
>>> going to be addressed under JDK-8134103.
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