RFR (S) JDK-8025004: -XX:+CheckUnhandledOops asserts for JDK 8 solaris sparc fastdebug binaries

[Lois Foltan]

On 10/3/2013 1:59 PM, Daniel D. Daugherty wrote:
> On 10/2/13 10:38 AM, Lois Foltan wrote:
>>
>> Please review the following fix:
>>
>> Webrev:
>>     http://cr.openjdk.java.net/~coleenp/bug_jdk8025004/
>
> src/share/vm/oops/instanceKlass.hpp
>     No comments.
>
> src/share/vm/oops/instanceKlass.cpp
>     No comments.
>
> Thumbs up.
>
> I realize that this particular instance of the compiler bug
> is somewhat artificial because it is only tickled when the
> CHECK_UNHANDLED_OOPS feature is used. However, my mind now
> wonders if this compiler bug impacts other uses of volatile
> in the VM and, if so, how do we detect it?
Hi Dan,
Thanks for the code review.  Yes, I have discussed this a bit with 
Coleen as well.  She was going to look through some of her work to 
check.  I did do a cursory look through the vm and most of the volatiles 
are of primitive or pointer types which is a non-issue. This bug also 
does not manifest itself if a data member within a class is defined 
volatile.
>
> Also, the bug says 'solaris sparc'. Is there some reason that
> this bug doesn't impact 'solaris x64'?
The bug does impact both sparc and x64 and this was reported in bugDB to 
the compiler team.  I will update the bug title.
Thanks again,
Lois

>
> Dan
>
>
>>
>> Bug: -XX:+CheckUnhandledOops asserts for JDK 8 solaris sparc 
>> fastdebug binaries
>>     https://bugs.openjdk.java.net/browse/JDK-8025004
>>
>> Summary of fix:
>>     This fix is to work around a Solaris Studio C++ 12u1 & 12u3 
>> compiler bug. Basically in fastdebug builds
>>     on Solaris, CHECK_UNHANDLED_OOPs is defined causing an oop to be 
>> defined as a class instead of a oopDesc *.
>>     Code within oops/instanceKlass.cpp defines several stack local 
>> variables as "volatile oop init_lock". Solaris Studio C++
>>     compilers erroneously call the oop's destructor twice for the 
>> volatile oop upon exit from the code segment
>>     within the member functions. Remove the keyword "volatile" from 
>> all "init_lock" stack local variables defined
>>     within oops/instanceKlass.cpp. This bug has been reported to the 
>> Solaris Studio C++ compiler team.
>>
>> Tests:
>>     JTREG, vm.quick.testlist on Solaris with -XX:+CheckUnhandledOops 
>> specified
>>
>> Thank you, Lois
>>
>>
>