A process doesn't always terminate, does it? For example, could it be
suspended and garbage collected?:
([Transcript show: 'hello'] forkAt: 30)
name: 'test';
suspend.
ObjectMemory garbageCollect.
(Process allInstances select: [:p | p name = 'test']) inspect
I suppose in your scenario the semaphores would keep the process from
being gc'd in the above example, but my point is that we cannot be 100%
sure the semaphores will eventually be signalled for every process,
because not every process runs to completion. Are there other
situations besides suspend/gc where a process would never terminate?
Dave
Georg Heeg wrote:
> All,
>
> In the ObjectStudio 8 project we have developed a solution for a similar
> task: In ObjectStudio 8 you can attach semaphore to a process which will be
> signalled when the process terminates.
>
> AR 50827 describes the setup to hook into class Process and introduces a new
> method called finalTerminate which calls primTerminate by default and is
> used in ObjectStudio 8 to be overridden by triggering any termination
> semaphore:
>
> finalTerminate
> (self environment at: #terminationSemaphores
> ifAbsent: [OrderedCollection new]) do: [:each | each
> signal].
> ^self primTerminate
>
> Maybe we can use this discussion to generalize the ObjectStudio 8 solution
> and to have it included directly in the base. I still hope that AR 50827
> will make it soon.
>
> Georg
>
> PS: This is the ObjectStudio 8 way to set up the semaphore (Method from
> class Process:
>
> waitForThreadExitMilliseconds: aNumber
> | sem coll result |
> sem := Semaphore new.
> coll := self environment at: #terminationSemaphores
> ifAbsent:
> [self environment at: #terminationSemaphores put:
> OrderedCollection new].
> coll add: sem.
> self isTerminated ifTrue: [^#Exit].
> result := (sem waitFor: aNumber) ifTrue: [#Exit] ifFalse:
> [#Timeout].
> coll remove: sem.
> ^result
> ":Section Reference waitForThreadExitMilliseconds: aNumber
> Description: Wait for the completion of this thread but no more than
> specified number of milliseconds. nil means
> indefinite
> wait.
> Assumptions: None.
> Return Value: A symbol.
> #Error -- error has occurred
> #Exit -- thread has terminated
> #Timeout -- wait has timed out
> Receiver Modified: No.
> :End"
>
> -----Ursprüngliche Nachricht-----
> Von:
[hidden email] [mailto:
[hidden email]]
> Gesendet: Freitag, 13. Oktober 2006 01:43
> An:
[hidden email]
> Cc:
[hidden email];
[hidden email]
> Betreff: Re: Terminate and #ensure: blocks [was: Re: How to be informed when
> a process terminates]
>
> [...]
>
>
Locked
