[9] RFR(XS): 8059735: make_not_entrant_or_zombie sees zombies

[Tobias Hartmann]

Hi,

please review the following patch.

Bug: https://bugs.openjdk.java.net/browse/JDK-8059735
Webrev: http://cr.openjdk.java.net/~thartmann/8059735/webrev.00/

Problem:
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 [1] 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.

Solution:
Use a MutexLockerEx with the '_no_safepoint_check_flag' to acquire the 
CompiledIC_lock.

Testing:
- Failing tests
- JPRT

Thanks,
Tobias

[1] https://bugs.openjdk.java.net/browse/JDK-8058737
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/attachments/20141007/122a74d7/attachment.html>