[Zope3-dev] Potential bug of intid

[Gary Poster]

On Dec 11, 2005, at 4:23 AM, Tadashi Matsumoto wrote:

> Hello
>
> I was looking into the following code of intid's __init__.py.
...
>
> I think it is better to use, for example, 2**30 instead of 2**31.

Looks like a good catch to me.

Also looks like 2**31 -1 would be sufficient (typical sys.maxint),  
rather than 2**30...or maybe just sys.maxint (though I wouldn't be  
surprised if the author had consciously rejected maxint for database  
portability).

> By the way, there is a probability (less than 1/2**31 percent) of
> generating same intids, if thread switching occurs between the line
> 114 and 115.

At which point you should get a conflict error, which in Zope would  
cause one of the transactions to be retried without the user's  
knowledge and everything would still be good.

Gary