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

[Christian Thalinger]

On May 18, 2012, at 12:16 PM, Christian Thalinger wrote:

> 
> On May 16, 2012, at 9:12 AM, Vladimir Kozlov wrote:
> 
>> Kris,
>> 
>> Changes looks good. I will push it tomorrow.
> 
> I created:
> 
> 7170053: crash in C2 when using -XX:+CountCompiledCalls
> 
> and will push it in a minute.  Thanks for the fix.

Here is the webrev (for the record):

http://cr.openjdk.java.net/~twisti/7170053/

-- Chris

> 
> -- Chris
> 
>> 
>> 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
>>> 
>>> 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
>>> 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
>