Request for review (XS): crash in C2 when using -XX:+CountCompiledCalls

[Krystal Mok]

Thank you, Vladimir :-)

- Kris

On Thu, May 17, 2012 at 12:12 AM, Vladimir Kozlov <
vladimir.kozlov at oracle.com> wrote:

> Kris,
>
> Changes looks good. I will push it tomorrow.
>
> Thanks,
> Vladimir
>
>
> On 5/16/12 6:02 AM, Krystal Mok wrote:
>
>> Hi all,
>>
>> Could I get some reviews for this patch, please?
>> https://gist.github.com/**2710000#file_count_compiled_**calls.patch<https://gist.github.com/2710000#file_count_compiled_calls.patch>
>>
>> Description:
>>
>> C2 may crash when compiling methods with -XX:+CountCompiledCalls turned
>> on. The cause is
>> in Parse::count_compiled_calls(), where it made a TypeInstPtr from a
>> ciMethod:
>>
>> const TypeInstPtr* addr_type = TypeInstPtr::make(method());
>>
>> Since the klass of a ciMethod is a ciMethodKlass, which isn't a
>> ciInstanceKlass, an assertion is hit later in
>> Compile::flatten_alias_type(), where it's expecting a TypeInstPtr to have
>> a ciInstanceKlass:
>>
>> ciInstanceKlass *k = to->klass()->as_instance_**klass();
>>
>> An example of the crash is available here: https://gist.github.com/**
>> 2710000 <https://gist.github.com/2710000>
>> In the example, I started a Groovy shell with -XX:+CountCompiledCalls
>> set, and it crashed quickly when compiling
>> java.lang.String.charAt().
>>
>> The fix is to use TypeOopPtr::make_from_**constant(method()) instead of
>> TypeInstPtr::make(method()).
>> I did check the hg history, and looks like it's been like this since
>> duke at 0. Wonder if there's any history behind this.
>>
>> Note that this fix may have to be changed again when methodOopDesc's are
>> moved out of PermGen.
>>
>> Regards,
>> Kris
>>
>
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