[Vm-dev] how many free bits we have in Object Header?

Mariano Martinez Peck marianopeck at gmail.com
Tue May 4 09:49:11 UTC 2010


Hi folks. I think I am using the last free bit in the object header. For the
moment, I am using this:

ObjectMemory >> initializeObjectHeaderConstants

.....

"masks for root and mark bits"
    MarkBit := 1 bitShift: BytesPerWord*8 - 1.  "Top bit"
    RootBit := 1 bitShift: BytesPerWord*8 - 2.  "Next-to-Top bit"
    AllButMarkBit := WordMask - MarkBit.
    AllButRootBit := WordMask - RootBit.

    AllButMarkBitAndTypeMask := AllButTypeMask - MarkBit.

    UsedObjectBit := 1 bitShift: BytesPerWord*8 - 3.  "Next-to-Top bit"
    AllButUsedBit := WordMask - UsedObjectBit.



Now...the question is, is there another free bit in the object header ? I
need another one :(

Thanks

Mariano
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.squeakfoundation.org/pipermail/vm-dev/attachments/20100504/9ddffade/attachment.htm


More information about the Vm-dev mailing list