On Thu, May 13, 2010 at 10:56 AM, Thomas Davie <[email protected]> wrote: > > On 13 May 2010, at 15:33, Eric Gorr wrote: > >> So long as it is ok for the string to be unique for the network the user is >> on only. From the docs: >> >> The ID includes the host name, process ID, and a time stamp, which ensures >> that the ID is unique for the network. >> >> A UUID (Universally Unique Identifier) is entirely unique. > > No it's not, as can easily be proven by observing that there are only a > finite number of 40 character strings. A UUID is probabilistically unique.
CFUUID includes the MAC address, so unless your MAC address is cloned or you manage to generate two UUIDs on the same device in the same 100ns time interval or the calendar rolls over (which will take about 3700 years), they are entirely unique within the universe of CFUUID strings. Mike _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
