<Swing Dev> [9] Review Request for 8030702: Deadlock between subclass of AbstractDocument and UndoManager

[Semyon Sadetsky]

UndoManager stores this reference if it is assigned for an Abstract 
document. I can wrap it with a WeakReference.
   >>> It looks like AbstractDocument violates UndoManager 
synchronization contract when it both use lock to work with UndoManager 
and in the implemented undo() method.
It is definitely about that. But what is your point?

--Semyon

On 7/30/2015 3:26 PM, Alexander Scherbatiy wrote:
> On 7/28/2015 8:24 PM, Semyon Sadetsky wrote:
>> Hello,
>>
>> Please review fix for JDK9:
>> bug: https://bugs.openjdk.java.net/browse/JDK-8030702
>> webrev: http://cr.openjdk.java.net/~ssadetsky/8030702/webrev.00/
>>
>> The deadlock happens if undo/redo is called on the document while its 
>> content is being updated from another thread.
>> The proposed solution is to reorder mutex acquisitions in the undo 
>> manager assigned to an AbstractDocument. Document's lock is obtained 
>> in its undo manager with a minimal change of the current API. A 
>> stress test scenario is added to reproduce the issue.
>
>    UndoManager is a general class that can be used not only by 
> AbstractDocument. It does not seem as good idea to store references 
> from other classes that have deadlocks with UndoManager in the 
> UndoManager.
>    It looks like AbstractDocument violates UndoManager synchronization 
> contract when it both use lock to work with UndoManager and in the 
> implemented undo() method.
>
>   Thanks,
>   Alexandr.
>
>>
>> --Semyon
>>
>