Re: [Pharo-project] is it possible to know the memory occupation (bytes) of an object?

Sept. 21, 2010

      On Tue, Apr 27, 2010 at 1:19 PM, Adrian Lienhard <adi@netstyle.ch> wrote:
...
Its a simple method in Object:
Object>>sizeInMemory
       "Returns the number of bytes used by this object in memory
(including its header)"
| headerSize instanceSize |
       headerSize := (self class indexIfCompact > 0 ifTrue: [ 4 ] ifFalse:
[ 8 ]).
       instanceSize := (self class isVariable
               ifFalse: [ self class instSize * Smalltalk wordSize ]
               ifTrue: [ (self basicSize * (self class isBytes
                       ifTrue: [ 1 ] ifFalse: [ Smalltalk wordSize ])) ]).
       ^ headerSize + instanceSize
Hi Adrian. Sorry for returning to this thread. I am trying to contemplate
all the cases.

I was looking at SpaceTally and I found that maybe a better implementation
could be something like this:

Object >> sizeInMemory
    "Answer the number of bytes consumed by this instance including object
header."

    | isCompact instVarBytes bytesPerElement headerBytes total contentBytes
|
    isCompact := self class indexIfCompact > 0.
    instVarBytes := self class instSize * 4.
    self class isVariable
        ifTrue: [
            bytesPerElement := self class isBytes ifTrue: [1] ifFalse: [4].
            total := 0.
            contentBytes := instVarBytes + (self basicSize *
bytesPerElement).
                headerBytes :=
                    contentBytes > 255
                        ifTrue: [12]
                        ifFalse: [isCompact ifTrue: [4] ifFalse: [8]].
                total :=  headerBytes + contentBytes.
            ^ total]
        ifFalse: [
            headerBytes :=
                instVarBytes > 255
                    ifTrue: [12]
                    ifFalse: [isCompact ifTrue: [4] ifFalse: [8]].
            ^ headerBytes + instVarBytes ].

I guess I did some mistake but if we can arrive to a good implementation it
would be really cool.

Thanks

mariano
...
Please also note the other mail I sent to this thread.
Adrian
On Apr 27, 2010, at 13:16 , Mariano Martinez Peck wrote:
...
On Tue, Apr 27, 2010 at 12:45 PM, Adrian Lienhard <adi@netstyle.ch>
wrote:
...
I once sent some code to the mailing list (search for thread named "Size
of
objects").
Thanks Adrian...I couldn't find it. Can you forward it to me please?  or
just send me the code...
...
We should add this to the image. I think I named it #sizeInMemory.
There are only changes to the image side ?  or the vm also ?
Thanks
Mariano
...
Adrian
On Apr 27, 2010, at 12:03 , Mariano Martinez Peck wrote:
...
Hi. I don't know if "memory occupation" is the better name. I just want
to
know the amount of memory that an object is occupying in RAM. I mean,
the
amount of bytes.
Is this possible ? if true, how ?   I would like to do it from both
sides:
image and VM.
I checked both but I didn't find anything.
Thanks in advance
Mariano
_______________________________________________
Pharo-project mailing list
Pharo-project@lists.gforge.inria.fr
http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________
Pharo-project mailing list
Pharo-project@lists.gforge.inria.fr
http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________
Pharo-project mailing list
Pharo-project@lists.gforge.inria.fr
http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
_______________________________________________
Pharo-project mailing list
Pharo-project@lists.gforge.inria.fr
http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project