[cells-devel] assertion failure in c-pulse-update (CVS latest)

[Ken Tilton]

On 9/12/06, Jack Unrue <jdunrue at gmail.com> wrote:
>
> I've upgraded to the latest CVS version of Cells and have encountered
> the following assertion failure:
>
> *** - (>= CELLS::*DATA-PULSE-ID* (CELLS::C-PULSE CELLS::C)) must evaluate
> to a
>       non-NIL value.
>
> which had not occurred previously (I can't say what version, but I
> would say more than a couple months ago). I believe the key is that I'm
> calling cells:cells-reset and then attempting to invoke an accessor on a
> model
> object that existed prior to the cells-reset call. This used to work OK,
> but
> perhaps I've been getting away with something I shouldn't have been?


I think the deal is this (you are right):

1. Cells-reset has always reset the vital *data-pulse-id* to 0
2. Old model object cells still in use when cells-reset was invoked thus
have always had DPs (datapulses) greater than *data-pulse-id*, obviously
benignly so in your application.
3. I have an insanely high degree of confidence that the assertion above was
inserted in the past month after I debugged a tough problem in which an
object DP got moved backwards. (This had to do with another new
mechanism,integrity bubbles, which I happen to plan to back out.)

So...you can:

1. chop the assertion
2. suggest a new cells-reset-a-little, or a cells-reset parameter which says
"I want to reset this but not that"

Re the latter, i admit Cells are a little un-Lispy in that I have not worked
much on restarts. But the function cells-reset is meant to truly reset the
cells mechanism, so as you surmised I am surprised you got away with it at
all. I almost think then that, in your testing, you might want to simply
arrange things so that cells-reset does not get called unless you are truly
reinitializing your own application -- that is the spirit of cells-reset.*

kt

* uh-oh, now I am in a panick over someday doing persistent cells again. :)
look for datapulse-id to become:

        (+ (* 10000 (get-internal-real-time) (incf "oldskool-dp*))

Where *oldskool-dp* gets zeroed when g-i-r-t changes.

kt
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.common-lisp.net/pipermail/cells-devel/attachments/20060913/2c31cebb/attachment.html>