On Mon, Oct 27, 2014 at 9:19 AM, Levente Uzonyi leves@elte.hu wrote:
On Mon, 27 Oct 2014, Clément Bera wrote:
Hey guys,
I was discussing about methods like that with Marcus:
MyClass>>foo #(false) first ifFalse: [ 'first call since compilation' logCr. #(false) at: 1 put: true ] ifTrue: [ 'other calls' logCr ]
DoIt: 4 timesRepeat: [MyClass new foo ]
Transcript: 'first call since compilation' 'other calls' 'other calls' 'other calls'
In the sista image/VM, we are most probably going with Eliot to implement a slow path when you edit the literal of a method (deoptimizing the method) so we can consider that the literals are immutable in the generic case (and if it's not true, execution falls back to a slow path).
But I was thinking, does it worth it to implement the slow path ? Couldn't we just put literals as immutable all the time ? The methods as the one shown before would not work any more. But does someone use it ?
This method was used in Seaside (or some Seaside extension) to cache the contents of files in methods.
By the way, how would you ensure immutability?
See my message earlier in the thread. Via a per-object isImmutable bit.
I mean, how would you prevent something like this?
MyClass >> foo
^#('placeHolder')And then
(((MyClass >> #foo) literalAt: 1) at: 1) becomeForward: Object new
Levente
P.S.: why isn't this on the vm-dev list?
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