On Mon, May 9, 2011 at 5:06 PM, Igor Stasenko <siguctua@gmail.com> wrote:

On 9 May 2011 16:01, Mariano Martinez Peck <marianopeck@gmail.com> wrote:
> Another that....all those incorrect compiled method has the same:� they miss
> the bytecode 120 (self return), and they ALL have the same last byte: 32.
> what that 32 can be?� I don't know...
>

This is indicating a trailer kind:

((CompiledMethod allInstances select: �[:each | each trailer kind =
#VarLengthSourcePointer] ) ) first trailer kindAsByte
�32

32 stands for #VarLengthSourcePointer trailer.

ahaaaa!!� I didn't know that ;)

�

And i have plenty of methods with #VarLengthSourcePointer in my image

((CompiledMethod allInstances select: �[:each | each trailer kind =

#VarLengthSourcePointer] ) ) size 4387

because my .changes file go over 32Mb "limit".

So...when the .changes file is over 32 bits, the default trailer is #VarLengthSourcePointer ?

BTW, do you know how can I create a CompiledMethod for testing with this kind of trailer ?

�

Now to check what is going on, we should run a following:

methods := ((CompiledMethod allInstances select: �[:each | each
trailer kind = #VarLengthSourcePointer] ) ).

methods := methods select: [:m | m isInstalled ]. "we don't care about
not-installed ones"

No, non of the methods is installed.� So that script answers an empty array.

�

and for installed we should verify that after compilation it from source code,
it ends up with same bytecode as in currently installed method.

| methods |

methods := ((CompiledMethod allInstances select: �[:each | each
trailer kind = #VarLengthSourcePointer] ) ).
methods := methods select: [:m |
� � � �| cls |
� � � �cls := m methodClass.
� � � �cls isObsolete not and: [ (cls compiledMethodAt: m selector) == m ] ].

methods select: [:m |
� � � �| m2 |
� � � �m2 := m methodNode generate.

� � � �((m initialPC = m2 initialPC and: [m endPC = m2 endPC ]) and: [
� � � � � � � �(m initialPC to: m endPC) allSatisfy: [:i | (m at: i) = (m2 at: i)] � � ]) not
].

In my image the result of doit is empty array.
Note that endPC is calculating based on trailer data. So if trailer is
not correct, it would affect the comparison.
So, it could fail if source code pointer is not valid or endPC
calculation is wrong.
But for all methods it is correct.

Thanks for the help. In fact, since non of them is installed, I also have that array empty.

The problem is the code (like mine) that does� CompiledMethod allInstances directly...without filtering by #isInstalled. Depending on what they do it can even be a crash (as it happened to me).

So I would like to still know:
1) while those fucking CMs are not GCed
2) how they can be generated.

I have spent the whole day and I couldn't :(�� I am more interested in 1)
Notice that I didn't do anything weird. I just took the default Pharo1.3 image.

Thanks Igor for your help.