<AWT Dev> [9] Review Request: 8165717 Various memory leaks in jdk9

[Anton Tarasov]

Hi Sergey,

The fix looks correct to me.

On 9/14/2016 6:35 PM, Sergey Bylokhov wrote:
> Hello.
>
> Please review the small fix for jdk9. Note that I plan to backport it 
> to jdk8:
That would be really good, thanks!

Regards,
Anton.

>
> NSApplicationAWT class have a special method which posts event to the 
> native queue. This event is used to execute the block of code which 
> contains CFRelease for some native resource. It was implemented in 
> this way (instead of simple "performOnmMainThread") because we should 
> filter this event when the nested native loop is active. The problem 
> is that this method overretain the block. [block copy] copy the block 
> from the stack and retain it(or just retain if the block is in memory 
> already), and since we retain it again we get a memory leak, because 
> we release it only once in NSApplicationAWT.sendEvent(). The leak is 
> quite small but the code can be executed lots of time which cause 
> allocation of unreasonable amount of memory. There is no test since 
> the leak is native, and it will be necessary to spend lots of time to 
> fill the whole native memory and swap.
>
> The bug was found when I worked on 'other fix', and some other memory 
> leaks will be fixed separately in 'other fix'.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8165717
> Patch can be found at: http://cr.openjdk.java.net/~serb/8165717/webrev.00
>