[OpenJDK 2D-Dev] [14] RFR JDK-8235147: Release HDC from passiveDCList sooner

[Alexey Ivanov]

I'm still waiting for a second reviewer.

Anyone?
Thank you in advance!


On 17/02/2020 12:56, Alexey Ivanov wrote:
> Thank you, Sergey, for your review!
>
> Any other volunteers?
>
>
> On 06/02/2020 23:10, Sergey Bylokhov wrote:
>> Looks fine.
>>
>> On 2/6/20 1:39 pm, Alexey Ivanov wrote:
>>> Hello once again,
>>>
>>> After trying a few things suggested by Sergey, I found serious 
>>> issues in the new approaches although the code looked a bit cleaner. 
>>> Resolving those issues requires substantial changes to the way we 
>>> handle the active and passive DC lists.
>>>
>>> Thus, it's safer to postpone further refactoring to a later time.
>>>
>>> So we're back to the original proposal.
>>>
>>> I'm quoting it for your convenience below:
>>>
>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8235147
>>> Webrev: http://cr.openjdk.java.net/~aivanov/8235147/webrev.00/
>>>
>>>
>>> When a DC becomes unused, it is moved from activeDCList to 
>>> passiveDCList to be released later. It will stay in the 
>>> passiveDCList until a new DC is requested for the same window or the 
>>> window is destroyed.
>>>
>>> The DCs in passiveDCList will never be used again, so we can release 
>>> them as soon as another request for a DC comes in.
>>>
>>> The test case, ManyFramesTest.java, attached to the bug creates and 
>>> displays 10 frames. Then it hides the 9 frames. At this point, 
>>> passiveDCList contains 9 entries. These DCs will not be released 
>>> until the corresponding frame is shown and painted again or the 
>>> frame is destroyed.
>>>
>>>
>>> The fix releases all DCs currently in passiveDCList when another DC 
>>> is requested.
>>> With the fix, when running ManyFramesTest.java test case, the number 
>>> of entries in passiveDCList does not grow, the list contains at most 
>>> 1 entry.
-- 
Regards,
Alexey