Request for review (S) 7012088: jump to 0 address because of lack of memory ordering in SignatureHandler::add

[Dmitry Samersoff]

Coleen,

Should we NULL-check _handlers in the code also, before accessing it?

-Dmitry


On 2011-02-01 21:20, Coleen Phillimore wrote:
>
> Dmitry,   You are absolutely right.  We should check _handlers under the
> lock too.  It could be created in a separate thread.
>
> Thanks!
> Coleen
>
> On 2/1/2011 1:14 PM, Dmitry Samersoff wrote:
>> Coleen,
>>
>> assert code is not clean for me:
>>
>> if (_handlers != NULL){
>> }
>>
>> _handlers never checked for NULL before e.g. during printing we
>> use _handlers->length() etc.
>>
>> if we are fighting against race I guess we should take a lock before
>> null check.
>>
>> i.e.
>>
>> MutexLocker mu(SignatureHandlerLibrary_lock);
>> if (_handlers != NULL) {
>> ....
>>
>> -Dmitry
>>
>>
>> On 2011-02-01 19:48, Coleen Phillimore wrote:
>>> Summary: Write method signature handler under lock to prevent race with
>>> growable array resizing
>>>
>>> Also includes a fix to 6704010 which was broken with
>>> -XX:-UseFastSignatureHandlers
>>>
>>> This change was submitted and tested by the customer.
>>>
>>> open webrev at http://cr.openjdk.java.net/~coleenp/7012088/
>>> bug link at http://bugs.sun.com/view_bug.do?bug_id=7012088
>>>
>>> Thanks,
>>> Coleen
>>
>


-- 
Dmitry Samersoff
Java Hotspot development team, SPB04
* There will come soft rains ...