[Vm-dev] Explicitly avoiding process switch
henrik.s.johansen at veloxit.no
Thu Aug 11 13:56:20 UTC 2011
On Aug 11, 2011, at 2:59 56PM, Igor Stasenko wrote:
> On 11 August 2011 14:28, Henrik Johansen <henrik.s.johansen at veloxit.no> wrote:
>> On Aug 11, 2011, at 2:11 37PM, Igor Stasenko wrote:
>> On 11 August 2011 13:17, Nicolas Cellier
>> <nicolas.cellier.aka.nice at gmail.com> wrote:
>> I would properly comment the places where this "ATOMIC" operation is
>> really used.
>> Like in
>> AtomicQueueItem>>makeCircular? :)
>> I also remember discussion that some precautions in code to not insert
>> suspension point(s) in ProcessorScheduler/Process/or Semaphore..
>> but i forgot which one exactly.
>> Is it LinkedList>>removeLink:?
>> So suspension points in remove:ifAbsent (as written now) and removeLink: are ok.
>> Not in removeLink:ifAbsent: though.
>> Used to be:
>> link := self linkOf: aLinkOrObject ifAbsent: [^aBlock value].
>> self removeLink: link.
> i don't like this code, because it iterating list twice, first to find a link,
> and second time to remove it.
> I don't think it is a big secret that removing an element from linked
> list could be done using single iteration :)
You really only need to iterate to find the correct one if passed a non-link.
So the following is probably better:
linkOf: anObject ifAbsent: errorBlock
anObject asLink == anObject ifTrue: [^anObject].
linksDo: [:el | el value = anObject
ifTrue: [^ el]].
^ errorBlock value
ll := LinkedList new.
link := ll addFirst: 5.
ll remove: link ifAbsent: [self halt]
works without halting as well :)
More information about the Vm-dev