RFR (S) JDK-8178712: ResourceMark may be missing inside initialize_[vi]table

[Calvin Cheung]

On 7/10/18, 12:34 PM, Lois Foltan wrote:
> On 7/10/2018 3:10 PM, Calvin Cheung wrote:
>
>> Hi Lois,
>>
>> I'm wondering if the ResourceMark in the following function in 
>> universe.cpp could be removed?
>> If I understand the code correctly, the ResourceMark is necessary for 
>> Universe::reinitialize_itables() which calls into 
>> klassItable::initialize_itable() where you've added ResourceMark with 
>> your change.
>>
>> bool universe_post_init() {
>>   assert(!is_init_completed(), "Error: initialization not yet 
>> completed!");
>>   Universe::_fully_initialized = true;
>>   EXCEPTION_MARK;
>>   { ResourceMark rm;
>>     Interpreter::initialize();      // needed for interpreter entry 
>> points
>>     if (!UseSharedSpaces) {
>>       HandleMark hm(THREAD);
>>       Klass* ok = SystemDictionary::Object_klass();
>>       Universe::reinitialize_vtable_of(ok, CHECK_false);
>>       Universe::reinitialize_itables(CHECK_false);
>>     }
>>   }
>
> Thanks Calvin for the review!  I wondered that as well, but I think 
> the ResourceMark may be needed for the Interpreter::initialize(). For 
> example, it calls TemplateTable::initialize() which logs timer 
> information which I suspect may need a ResourceMark.  So, it wasn't 
> clear that the ResourceMark in universe_post_init() was solely needed 
> for the reinitialize_vtable and itables.
In timerTrace.hpp:
// TraceTime is used for tracing the execution time of a block
// Usage:
//  {
//    TraceTime t("some timer", TIMERTRACE_LOG(Info, startuptime, tagX...));
//    some_code();
//  }
//

I looked at several usage of TraceTime and they all don't have 
ResourceMark before it.

I'm fine with leaving the ResourceMark in universe_post_init() if you 
want to play it safe.

thanks,
Calvin

>
> Thanks,
> Lois
>
>>
>> It looks good otherwise.
>>
>> thanks,
>> Calvin
>>
>> On 7/10/18, 10:19 AM, Lois Foltan wrote:
>>> Please review this clean up change to correctly set ResourceMark 
>>> from within klassVtable::initialize_vtable() and 
>>> klassItable::initialize_itable() when applicable, instead of having 
>>> all instances of calls to these two methods establish a ResourceMark 
>>> unnecessarily prior to.
>>>
>>> open webrev at http://cr.openjdk.java.net/~lfoltan/bug_jdk8178712/
>>> bug link at https://bugs.openjdk.java.net/browse/JDK-8178712
>>>
>>> Testing: hs-tier1-3, jdk-tier1-3 (complete)
>>>                hs-tier4-5 (in progress)
>>>
>>> Thanks,
>>> Lois
>