Re: LE.2.1 Characteristics of a Lease

Gregg Wonderly wrote:
> Bob Scheifler wrote:
>>> Okay, so a lease, is open ended.
>>
>> Many leases are, but a lease doesn't have to be open ended.
>> Your policy could for example be to hand out an initial 30 minute lease,
>> and then deny all attempts to renew past that original expiration.
>> Or your policy could be to hand out an initial 5 minute lease,
>> and then honor renewals as long as they don't extend the
>> expiration more than 6 hours past the original expiration.
> 
> Okay, but since none of this is visible as part of the "API" that exists 
> from LeaseFactory/Landlord's perspective, I believe this is a Landlord 
> implementation detail.  That's why I said before, that the Landlord 
> might be more integrated into the granter than the interface alludes to, 
> so that the granter can either be a part of what renew() decides, or 
> provide additional parameters when creating an instance of a particular 
> Landlord implementation.

As I said before, the Landlord generally *is* (as opposed to "part of") 
the grantor - so a tight integration is expected. If you look at 
Outrigger, OutriggerServer (which defines the private protocol between 
the Outrigger's proxy and the server) extends 
com.sun.jini.landlord.Landlord, and OutriggerServerImpl implements the 4 
  methods of the Landlord interface directly, it doesn't delegate them 
to some other object. You don't plug an object implementing Landlord 
into Outrigger, Outrigger is a Landlord.

What's going on here is that the Landlord interface isn't defining some 
policy object, but just the network protocol (in the Jini sense) that 
LandlordLeases use to callback to the server, we don't really expect 
implementations of the Landord interface that are standalone objects.

-- 
John McClain					[email protected]
Sun Microsystems, Inc.
Burlington, MA

And it is that way today. We are tricked by hope into starting
companies, beginning books, immigrating to this country and investing
in telecom networks. The challenges turn out to be tougher than we
imagined. Our excessive optimism is exposed. New skills are demanded.
But nothing important was ever begun in a prudential frame of mind.

         - David Brooks

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