Re: SturdyRef expiration dates
Kevin Reid <[email protected]>
| Newsgroups | gmane.comp.lang.e.general |
|---|---|
| Message-ID | <[email protected]> |
On Mar 19, 2008, at 21:19, Kevin Reid wrote: > SturdyRef objects carry around expiration dates, but don't seem to > use them for anything (such as letting their clients check them). > Have I missed something? MarkM, Dean and I discussed this today, and we came to the conclusion that the expiration field should be removed, until such time as we find a compelling reason to put it back. CapTP is complex enough already, and the expiration is neither necessary nor reliable. Also, I argue that the lifetime of practical SturdyRefs is essentially application-specific. There are many possibilities, which I shall now invent names for a subset of: * Ephemeral: lasts until the vat incarnation shuts down. * Timed: lasts for a specified duration. * Tied: lasts until the thing which it is a facet of is destroyed. * Leased: times out unless regularly renewed. * Permanent: lasts as long as the vat identity does. Only in the 'Timed' case does an expiration date convey potentially useful information, and it seems to me that this would be the least common type in practical systems. -- Kevin Reid <http://homepage.mac.com/kpreid/>