RFR 9: 8138696 : java.lang.ref.Cleaner - an easy to use alternative to finalization
Alan.Bateman at oracle.com
Wed Oct 14 14:01:20 UTC 2015
On 14/10/2015 14:54, Roger Riggs wrote:
> Being able to subclass the XXXCleanable classes allows more efficient
> implementation of the cleaners
> in both size and performance. The subclass adds the necessary state
> for the cleanup and implements
> the performCleanup method. Only a single object is created (and
> gc'd), reducing the size of headers
> and cross references between separate objects. Only the
> performCleanup method is overridable to
> maintain the robustness of the Cleaner implementation.
> If the XXXCleaner classes are not subclassed, a separate object is
> needed for the state and behavior.
> Either that extra object is created by the binding if lambda is used,
> or by the class needing the cleanup.
> It is not a big cost but is proposed to optimize the design and
> Peter's email  provided another description of the use case for
> I'm working on a webrev to show how the Cleaner would be used instead
> of finalizers
> and it will show use use of both lambdas and explicit cleanup classes.
No issue with sub-classing for the implementation, it's just not clear
why they need to be in the public API.
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