Hi Marcell,

On Mon, 11 Apr 2016, marcel.taeumel wrote:

> Hi, there!
>
> Please, have a look at WorldState >> #runStepMethodsIn:, which processes the
> list of deferred UI messages in a loop:
>
> runStepMethodsIn: aWorld
> 	"Perform periodic activity inbetween event cycles"
> 	| queue msg limit stamp |
> 	"Limit processing of deferredUIMessages to a max. amount of time"
> 	limit := self class deferredExecutionTimeLimit.
> 	stamp := Time millisecondClockValue.
> 	queue := self class deferredUIMessages.
> 	[(Time millisecondsSince: stamp) >= limit
> 		or:[(msg := queue nextOrNil) == nil]]
> 			whileFalse: [msg value].
> 	"..."
>
> There is a time limit to keep the UI responsive.
>
> Now look at WeakArray class >> finalizationProcess:
>
> finalizationProcess
>
> 	[FinalizationSemaphore wait.
> 	 FinalizationLock
> 		critical:
> 			[FinalizationDependents do:
> 				[ :weakDependent |
> 				weakDependent ifNotNil:
> 					[weakDependent finalizeValues]]]
> 		ifError:
> 			[:msg :rcvr | rcvr error: msg]] repeat
>
> Could be add a "Process yield" in the loop to keep the system responsive
> when facing complex finalization routines? Or would that just post-pone the

The finalization process runs at priority 50, so #yield wouldn't make the 
UI more responsive at all, only delays would.

> problem? We could add support for having many-many small finalizers, which
> add up to a big amount of time to finalize. Like Morphic's deferred UI
> message handling does.

Finalization will change as soon as the VMs support ephemerons. It might 
be the case that they already do.

>
> What about priorities? At the moment, we have to ways to specify the
> priority at which priority Object >> #finalize is called.
>
> Has this finalization mechanism been used extensively in some project?

In a Trunk image Files, Sockets and HostWindowProxies use the finalization 
process. Files rely on the higher priority of it. They keep forcing GCs 
until there's a new file descriptor available, which only works when the 
finalization process is able to release one. So, I think currently there 
would be a problem when a higher priority process were trying to open 
files and all file descriptors were in use.

Levente

>
> Best,
> Marcel
>
>
>
> --
> View this message in context: http://forum.world.st/WeakArray-finalization-never-yields-tp4889361.html
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>
>