RFR: 8215206: VtableStubs::find_stub is not appropriately protected by VtableStubs_lock

[Erik Österlund]

Hi Tobias,

On 2018-12-11 12:55, Tobias Hartmann wrote:
> Hi Erik,
> 
> looks good to me too.

Thanks for the review!

> Any reason you are not using [1] for your webrevs? The sdiffs seem to be slightly different (worse).

Yeah, I'm using git!

Thanks,
/Erik

> Best regards,
> Tobias
> 
> [1] http://hg.openjdk.java.net/code-tools/webrev/raw-file/tip/webrev.ksh
> 
> On 11.12.18 12:10, Erik Österlund wrote:
>> Hi,
>>
>> In VtableStubs::find_stub we first perform a lookup in the table to check for already created stubs
>> under the VtableStubs_lock, then if not found we create a new stub without the lock held, and then
>> insert it under the VtableStubs_lock without checking for entries inserted between the lookup and
>> insertion.
>> If the VtableStubs_lock is to protect the table (which is the intention), the lock should not be
>> unlocked before lookup and insert.
>>
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8215206
>>
>> Webrev:
>> http://cr.openjdk.java.net/~eosterlund/8215206/webrev.00/
>>
>> Thanks,
>> /Erik