RFR(XS): 8059735: make_not_entrant_or_zombie sees zombies
tobias.hartmann at oracle.com
Tue Oct 7 12:24:14 UTC 2014
thanks for the information, I didn't know that.
I will change the fix according to Albert's proposal.
On 07.10.2014 13:35, Mikael Gerdin wrote:
> Hi Tobias,
> On 2014-10-07 13:03, Tobias Hartmann wrote:
>> please review the following patch.
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8059735
>> Webrev: http://cr.openjdk.java.net/~thartmann/8059735/webrev.00/
>> In 'NMethodSweeper::process_nmethod' a non-entrant nmethod is processed
>> and can be converted to zombie (line 549 of sweeper.cpp). To clean the
>> IC stubs of that nmethod  we acquire the CompiledIC_lock and check
>> for a safepoint. In this case, there is a safepoint request and we
>> block. During the safepoint a VM_Deoptimize operation is executed (due
>> to classloading) and the non-entrant nmethod is set to zombie by
>> 'CodeCache::make_marked_nmethods_zombies'. After the safepoint the
>> sweeper continues and tries to set the nmethod to zombie again.
>> Use a MutexLockerEx with the '_no_safepoint_check_flag' to acquire the
> This is an unsafe operation which will lead to a deadlock.
> You _cannot_ mix taking a single lock object with and without
>> - Failing tests
>> - JPRT
>>  https://bugs.openjdk.java.net/browse/JDK-8058737
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