[Vm-dev] Problem with Proxies, objects and MethoDict

Mariano Martinez Peck marianopeck at gmail.com
Tue Sep 28 20:29:13 UTC 2010

Hi folks. I am trying to do something and I found a VM crash. Suppose I want
to swap out a class, do a become with a proxy (that with the DNU will load
the class back). In addition, I have instances of the swapped class.

Example of code (will crash in the last line):

o := MyObject new.
o foo: 123.
p := ClassProxy new.
p become: MyObject.
o == nil.
o foo.

My Object just extends Object, has an instVar 'foo',  and implements the

ClassProxy implements:

become: aClass
    className := aClass name.
    aClass fileOut.
    super become: aClass


doesNotUnderstand: aMessage
    | reloadedClass |
    (FileStream fileNamed: className, '.st') fileIn.
    reloadedClass := Smalltalk at: className.
    self becomeForward: reloadedClass.
    ^aMessage sendTo: reloadedClass

So....does someone know why the crash?

how can I solve it ?

Thanks in advance

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