[Glass] Confused about read only conflicts and RcIdentityBag

Mariano Martinez Peck via Glass glass at lists.gemtalksystems.com
Thu Aug 6 12:18:55 PDT 2015

On Thu, Aug 6, 2015 at 4:01 PM, Dale Henrichs via Glass <
glass at lists.gemtalksystems.com> wrote:

> On 08/06/2015 11:43 AM, Mariano Martinez Peck via Glass wrote:
> Hi,
> I have some collections that will be likely accessed and read from a few
> gems, quite possible at the same time. Since these collections will be
> written quite infrequently (and when done probably at a cron job at night),
> I thought I needed no RC class. However, I am reading the ProgGuide about
> RcIdenityBag and says:
> *However, no conflict occurs on instances of RcIdentityBag when any of
> these conditions exists: *
> *Any number of users read objects in the bag at the same time.  *
> So that means that if I do not use a RcIdentityBag (say I am using an
> OrderedCollection or SortedCollection), then multiple users cannot read the
> collection at the same time? mmmmmm sounds weird.
> If this is not the case, then I think the guide is confusing.
> I think the docs are confusing (sort of) ... we do have a conflict mode
> called a READ-WRITE conflict (see table 8-1 in the Committing Transactions
> section [1] of the programmers guide) and that is where objects in the
> StrongReadSet intersect the WriteSetUnion, but objects are not added to the
> StrongReadSet (a hidden set) unless you do it yourself ...
> So the comment in the docs are basically referring to the fact that the
> RcIdentityBag does not automatically add objects to the StrongReadSet ...
> this was done because in earlier versions of the product objects were added
> to the StrongReadSet automatically ... but that hasn't been done for awhile
> ...
> I will submit an issue about this ... thanks for noticing!

Ok, thanks for the clarification.

> Dale
> [1]
> http://downloads.gemtalksystems.com/docs/GemStone64/3.2.x/GS64-ProgGuide-3.2/8-Transactions.htm#pgfId-170009
> _______________________________________________
> Glass mailing list
> Glass at lists.gemtalksystems.com
> http://lists.gemtalksystems.com/mailman/listinfo/glass

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gemtalksystems.com/mailman/private/glass/attachments/20150806/c13be3f2/attachment.html>

More information about the Glass mailing list