[Vm-dev] normalSend, specialObjectsArray and VM

[Igor Stasenko]

Since during message send, you discovered particular method,
it should be also marked as 'used object', and all its literals etc.

On 3 October 2010 13:45, Mariano Martinez Peck <marianopeck at gmail.com> wrote:
>
>
>
> On Sun, Oct 3, 2010 at 12:42 PM, Bert Freudenberg <bert at freudenbergs.de> wrote:
>>
>>
>> What exactly are you trying to do?
>
> hehehe sorry. I am trying to "detect unused objects".
>
>>
>>  When do you consider an object to be "used"?
>
> When it receives a message. This is why I changed #normalSend
>
> Thanks in advance,
>
> Mariano
>
>
>>
>> - Bert -
>> On 03.10.2010, at 12:12, Mariano Martinez Peck wrote:
>>
>> Hi. I have a related question once again with this topic. I've changed Interpreter >> normalSend to something like this:
>>
>>
>> normalSend
>>     "Send a message, starting lookup with the receiver's class."
>>     "Assume: messageSelector and argumentCount have been set, and that
>>     the receiver and arguments have been pushed onto the stack,"
>>     "Note: This method is inlined into the interpreter dispatch loop."
>>     | rcvr |
>>     self inline: true.
>>     self sharedCodeNamed: 'normalSend' inCase: 131.
>>     rcvr := self internalStackValue: argumentCount.
>>     ((self isIntegerObject: rcvr) not and: [hasToTrace])
>>         ifTrue: [
>>             self internalTurnOnUsedBit: rcvr.
>>             ].
>>     lkupClass := self fetchClassOf: rcvr.
>>     receiverClass := lkupClass.
>>     self commonSend.
>>
>>
>> So...if it is not a SmallInetger and if the flag is on, I turn on a bit.
>>
>> The question is, if I send a normal message to a normal object. Example:
>>
>> | anObject |
>> anObject := MyClass new.
>> anObject foo
>>
>> Now...I am sure that "anObject" was marked with the bit. But what about:
>> a) the compiled method  MyClass >> #foo
>> b) MyClass
>>
>> should they be marked?
>>
>> In other words:
>>
>> self deny: (unUsed primitiveGetUsedBit: anObject).
>>     self deny: (unUsed primitiveGetUsedBit: anObject class).
>>     self deny: (unUsed primitiveGetUsedBit: (anObject class >> #foo)).
>>
>>      anObject foo.
>>
>>     self assert: (unUsed primitiveGetUsedBit: anObject).
>>     self assert: (unUsed primitiveGetUsedBit: anObject class).
>>     self assert: (unUsed primitiveGetUsedBit: (anObject class >> #foo)).
>>
>>
>> should all the asserts pass?  I ask because I don't know how CompiledMethods are executed (they receive a normalSend like any other object?) nor how class are accessed.
>>
>> Thanks in advance,
>>
>> Mariano
>>
>>
>> On Tue, May 11, 2010 at 5:43 PM, Igor Stasenko <siguctua at gmail.com> wrote:
>>>
>>> On 11 May 2010 17:40, Mariano Martinez Peck <marianopeck at gmail.com> wrote:
>>> >
>>> >
>>> >> >
>>> >> > Thanks Igor. I could see #class does not the normal way. It was logic as it already has the pointer there ;)
>>> >> >
>>> >> > Now I wonder...to avoid those special cases, do you think it makes sense to intercept in commonSend rather than commonSend ?  or it would be the same ?
>>> >> >
>>> >> err... commonSend or commonSend? i think it would be the same :)
>>> >>
>>> >
>>> > hahahah sorry, I meant commonSend instead of normalSend.
>>> >
>>> >
>>> >>
>>> >> the other point, where you can try intercept a send is cache lookup.
>>> >>
>>> >
>>> > internalFindNewMethod  ?
>>> >
>>>
>>> I don't know, maybe :)
>>>
>>> > Thanks
>>> >
>>> > Mariano
>>> >
>>
>>
>
>
>



-- 
Best regards,
Igor Stasenko AKA sig.