[Glass] Confused about read only conflicts and RcIdentityBag

[Dale Henrichs via Glass]

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!

Dale

[1] 
http://downloads.gemtalksystems.com/docs/GemStone64/3.2.x/GS64-ProgGuide-3.2/8-Transactions.htm#pgfId-170009
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