Unique id's

[Jon A. Lambert]

> From: clawrenc at cup.hp.com
> 
> In <199704100440.EAA378790 at out1.ibm.net>, on 04/09/97 
>    at 07:00 AM, cg at ami-cg.GraySage.Edmonton.AB.CA (Chris Gray) said:
> 
> >Some systems specifically avoid re-using ids, in order to better
> >catch dangling pointers.
> 
> Yeah, but I figure that the date check for the ObjectID (time_T value
> comparison of requested vs received objects) should pretty well trap
> most of them.
> 
Isn't it possible, especially in a multi-threaded system, to generate identical
IDs if you depend on date/time stamps?   I'm currently generating IDs just like 
Cold, except I'm using a big int and never fill in the holes.