Re: Common sense...

[Jeffrey Carter <jrcarter@acm.org>]

"chris.danx" wrote:
> 
> Additionally, each node in the list holds a count of the number of iterators
> and the number of objects which point to it (called positions as they
> represent a position in a list).  When both counts go to zero can a node be
> deallocated.  If a call to remove/delete is placed on a node, and the count
> of either is not zero, the node is marked and skipped by the appropriate
> subprograms (next, previous, has_next, has_previous, head, last).

Since iteration is atomic, I don't see how you can have more than one
iterator in action at once. In the presence of concurrency, you need to
have operations protected to ensure consistency; iteration would be one
of those operations.

Keeping a count of positions seems unnecessary. When a node is deleted,
any other positions pointing to it become invalid because you make the
node's ID invalid.

-- 
Jeff Carter
"I blow my nose on you."
Monty Python & the Holy Grail