Bob Rogers wrote:
>     From: Leopold Toetsch <lt@[...].at>
>     Date: Sat, 16 Jul 2005 11:38:41 +0200
>  
>     . . .
>  
>     We keep the invariant by several means:
>     . . .
>     c) a write barrier checks pointer stores into aggregates (by just 
>     comparing 2 memory addresses - basically)
>        we can do either:
>        - make aggregate younger (move to left)
>        - make stored-into object older (move to right)
>        - remember in IGP
>  
>  What happens when a store creates a cycle?  And how would this be
>  detected?

To keep the invariant we can't move the container nor the contained 
object, *if* both are aggregates. Therefore the pointer store will be 
recorded on the IGP list. Thus there is no need to detect cycles.

>  					-- Bob

leo