Serguei, OK. Closing as a dup.
-Dmitry On 2016-09-01 13:40, serguei.spit...@oracle.com wrote: > Hi David, > > Thank you for the comment. > > Dmitry, > > It seems, Chris and David are not comfortable with current fix. > Are you Ok to close this bug as a dup? > > Thanks, > Serguei > > > On 8/29/16 20:05, David Holmes wrote: >> Hi Serguei, >> >> On 30/08/2016 4:46 AM, serguei.spit...@oracle.com wrote: >>> Chris and David, >>> >>> We had a private discussion about this bug with Dmitry last week. >>> I initially suggested to close it as a dup of JDK-8134103 but then >>> agreed with a fix replacing crash symptom with AGENT_ERROR_INTERNAL. >>> I still have some doubt if it makes sense, as it does not look as >>> important. >>> >>> Now, it seems you also prefer to close this bug as a dup. >>> But let's check your opinion on the Dmitry's reasoning below. >> >> The problem is that the "fix" still doesn't guarantee that we will get >> the more informative AGENT_ERROR_INTERNAL. The whole situation is racy. >> >> But I won't block it and don't want to waste time arguing over it. So >> if Dmitry wants to proceed then you can count this as Reviewed. >> >> Thanks, >> David >> ----- >> >>> Thanks, >>> Serguei >>> >>> >>> On 8/29/16 06:12, Dmitry Samersoff wrote: >>>> Chris & David, >>>> >>>> JVMTI_ERROR_WRONG_PHASE problem is complicated and requires significant >>>> work probably on both JDWP and JVMTI side. Serguei plan to do it as a >>>> part of JDK-8134103 and not for JDK 9. >>>> >>>> So yes, we can close this one as a dup of JDK-8134103 - it has the same >>>> root cause and should be addressed as the part of JDK-8134103 >>>> (particularly, we have to cleanup ignore_vm_death logic) >>>> >>>> But the crash is observed only once in a nightly, so my intention is to >>>> save us a bit of time next time when this situation happens. >>>> >>>> i.e. before the changes we get JVMTI_ERROR_WRONG_PHASE message and >>>> *crash*, after the changes we get JVMTI_ERROR_WRONG_PHASE message >>>> and AGENT_ERROR_INTERNAL message. >>>> >>>> >>>> -Dmitry >>>> >>>> >>>> >>>> On 2016-08-29 09:43, Chris Plummer wrote: >>>>> 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. >>>>> >>>>> Chris >>>>>> David >>>>>> >>>>>>> thanks, >>>>>>> >>>>>>> Chris >>>>>>> >>>>>>> On 8/26/16 4:00 AM, Dmitry Samersoff wrote: >>>>>>>> Everybody, >>>>>>>> >>>>>>>> Please review the fix. >>>>>>>> >>>>>>>> http://cr.openjdk.java.net/~dsamersoff/JDK-8163994/webrev.02/ >>>>>>>> >>>>>>>> *Problem* >>>>>>>> >>>>>>>> Under some circumstances, when JVMTI_ERROR_WRONG_PHASE(112) is >>>>>>>> received, >>>>>>>> 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. >>>>>>>> >>>>>>>> *Solution* >>>>>>>> >>>>>>>> Guard added to jvmtiAllocate to get meaningful error message >>>>>>>> instead of >>>>>>>> crash. >>>>>>>> >>>>>>>> These fix doesn't fix root cause - JVMTI_ERROR_WRONG_PHASE >>>>>>>> problem is >>>>>>>> going to be addressed under JDK-8134103. >>>>>>>> >>>>>>>> -Dmitry >>>>>>>> >>>> >>> > -- Dmitry Samersoff Oracle Java development team, Saint Petersburg, Russia * I would love to change the world, but they won't give me the sources.
