[Vm-dev] [COG] primitiveClosureValue assert is failing with StackVM (possible BUG in bytecodes!!)

[Mariano Martinez Peck]

On Thu, Dec 23, 2010 at 7:00 PM, Eliot Miranda <eliot.miranda at gmail.com>wrote:

>
>
>
> On Thu, Dec 23, 2010 at 2:05 AM, Mariano Martinez Peck <
> marianopeck at gmail.com> wrote:
>
>>
>>
>>
>> On Wed, Dec 22, 2010 at 10:34 PM, Eliot Miranda <eliot.miranda at gmail.com>wrote:
>>
>>>
>>> Hi Mariano,
>>>
>>>     indeed it's a bug.  Your fix (objectMemory is: rcvr instanceOf: (self
>>> splObj: ClassBlockClosure) compactClassIndex:
>>> ClassBlockClosureCompactIndex) is the correct one.
>>>
>>
>> Thanks Eliot. But with that fix, the buytecode primitives are still
>> failing and not calling the primitive, but commonSend. So:
>>
>> 1) is this the expected behavior .. or
>>
>
> No.  The intension is for the value and value: bytecodes to directly invoke
> closure value.
>
>
>> 2) to fix that is not as I did it in my last fix but in some other place
>> that you will fix?
>>
>
> I'll try and fix once I can concentrate on Cog (I'm still focussed on
> Teleplace work until the week following xmas).
>
>


Ok, got it.


>
>>
>>
>>>  There are a few other places where this needs to be done also.  I'll
>>> roll out new code soon.
>>>
>>
>> Ok. Please let me know. I have some changes for better support of
>> SmallIntegers as methods. I can provide them if you want.
>>
>
> Please email me the change sets.
>

Done in email with subject "Couple of POSSIBLE Cog fixes". But notice the
"possible". I am not sure about them, but I think that at least it is worth
it to signal a warning ;)

Happy Christmas too all VM hackers!!

Mariano


>
> thanks!
> Eliot
>
>
>>
>> Cheers
>>
>> mariano
>>
>>
>>>
>>> best
>>> Eliot
>>>
>>> On Wed, Dec 22, 2010 at 12:03 PM, Mariano Martinez Peck <
>>> marianopeck at gmail.com> wrote:
>>>
>>>>
>>>> Hi Eliot. If I compile a StackVM, and I just press the left arrow in a
>>>> code pane of a OB windows, in a pharo image, I get an asser that fails:
>>>> (oop & 1) 19202
>>>>
>>>> Sorry I bother with these asserts, but I am trying to solve the crashes
>>>> I have and I think starting for the asserts is a good idea.
>>>>
>>>> The assert that fails is in primitiveClosureValue()  the part:
>>>>
>>>> blockClosure = longAt(GIV(stackPointer) + (GIV(argumentCount) *
>>>> BytesPerWord));
>>>>     /* begin quickFetchInteger:ofObject: */
>>>>     oop = longAt((blockClosure + BaseHeaderSize) + (ClosureNumArgsIndex
>>>> << ShiftForWord));
>>>>     assert((oop & 1));
>>>>     numArgs = (oop >> 1);
>>>>     if (!(GIV(argumentCount) == numArgs)) {
>>>>         /* begin primitiveFail */
>>>>         if (GIV(primFailCode) == 0) {
>>>>             GIV(primFailCode) = 1;
>>>>         }
>>>>         return;
>>>>     }
>>>>
>>>>
>>>> numArgs results to be a large number (using #printNum:   was 718613205),
>>>> and if I try to do a #printOop:  I got a " 0x55aa55aa0x55aa55aa is not on
>>>> the heap"
>>>>
>>>> Now, of course, the "if (!(GIV(argumentCount) == numArgs)) " fails.
>>>>
>>>> What it is funny is that I did a #printOop: of blockClosure instVar, and
>>>> this is what I get:  0x1f59b578: a(n) Association
>>>>
>>>> Association? WTF ?   so...I guess something weird is happening. I
>>>> continue debugging it..and I noticed that:
>>>>
>>>> - Several classes were called in addition to Association,like Character.
>>>> These seems to be compact classes and implement #value and #value:   ;)
>>>> - Both, #bytecodePrimValue and #bytecodePrimValueWithArg  were not
>>>> calling #primitiveClosureValue. So, "isBlock" was false...
>>>>
>>>> I tried modifying #bytecodePrimValueWithArg and #bytecodePrimValue  this
>>>> line:
>>>>
>>>> isBlock := objectMemory is: rcvr instanceOf: ClassBlockClosurecompactClassIndex: ClassBlockClosureCompactIndex.
>>>>
>>>> to this one:
>>>>
>>>> isBlock := objectMemory is: rcvr instanceOf: (self splObj:
>>>> ClassBlockClosure) compactClassIndex: ClassBlockClosureCompactIndex.
>>>>
>>>> WIth this change, at least, the assert doesn't fail anymore. I made
>>>> progress (maybe). But still, for normal closures, "isBlock" seems to be
>>>> false. So.....all block values are being managed as a normal send ????
>>>>
>>>> Now, I don't understand why ClassBlockClosureCompactIndex  is 0. I think
>>>> this may be the problem. Why it is not 12? (in Pharo  Smalltalk
>>>> compactClassesArray at: 12 ->>> BlockClosure.)
>>>> I notice that ObjectMemory >> initializeCompactClassIndices  does:
>>>>
>>>>     ClassBlockClosureCompactIndex := 0 "12". "Prospective.  Currently
>>>> TranslatedMethod class"
>>>>
>>>>
>>>> Notice that this ZERO changes the sematic of #is: oop instanceOf:
>>>> classOop compactClassIndex: compactClassIndex
>>>> called from the #bytecodePrimValue and bytecodePrimValueWithArg
>>>>
>>>> Finally, I changed the mentioned line to this:
>>>>
>>>> isBlock := objectMemory is: rcvr instanceOf: (self splObj:
>>>> ClassBlockClosure) compactClassIndex: 12.
>>>>
>>>> and finally, with block closures, it is calling the primitive, and for
>>>> Association it doesn't fail the assert.  ahh and the image doesn't crash ;)
>>>>
>>>> I don't know if this is a bug, if my solution was ok, nor it impact.
>>>> Please let me know.
>>>>
>>>> Cheers
>>>>
>>>> Mariano
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>
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