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

Semyon Sadetsky semyon.sadetsky at oracle.com
Thu Sep 15 09:43:02 UTC 2016



On 15.09.2016 11:08, Anton Tarasov wrote:
> 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

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