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

[Eliot Miranda]

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).


>
>
>
>>  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.

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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