Subject: Pine locking (fwd)

From: Ian Dunkin <[email-masked]>
Date: Fri, 28 Jan 1994 15:52:20 +0000 (GMT)

Had the following query from a user here.  I'm sure I've seen discussion
of this on the list, but it doesn't seem to have been implemented.  Would
it be a good thing to add?  In summary: 

  User runs Pine, leaves the session going

  User goes away and logs in from somwhere else; Pine correctly takes
    the lock from the first session

  User comes back to the first session.  Would like a way to grab
    _back_ the lock.

Thanks,

  I.

---------- Forwarded message ----------

Date: Fri, 28 Jan 1994 15:42:02 +0000 (GMT)
From: [...] one-of-our-users
Subject: Pine locking

When I dial-in to my workstaion & look at mail with Pine it is very good 
at grabbing the file locking, but when I get back to the console I have 
to quit Pine, then run it again to leave the read-only mode. Is there a 
way of getting the file lock back in Pine?

R.

---

From: Mark Crispin <[email-masked]>
Date: Fri, 28 Jan 1994 11:09:00 -0800 (PST)

I'm sorry, but it is extremely unlikely that this would ever be 
implemented, due to internal technical considerations.

``Having the lock'' means ``I know exactly what the mailbox file looks
like on disk, including where all the messages are located, and the only
thing anyone else can do to this mailbox is append to it.'' Conversely,
``not having the lock'' means ``I took a snapshot of the mailbox file some
time in the past, but I have no idea what it might look like now, so I had
better not try to do anything with that file again.''

The upshot of all of this is that ``grabbing back the lock'' is a 
meaningless concept.  The process which lost the lock no longer knows 
what is on the disk; rather, it just has a snapshot.

Consequently, the only way to get the lock again is to close the mailbox 
(discarding the snapshot) and re-opening it again.  You can do that with 
the appropriate commands in Pine, or by exiting Pine and running it again.

We may, in a future version, create an automatic way to do this that 
would simulate the behavior you've requested (``grabbing back the lock'') 
but in reality it would be doing a close/re-open operation.  The issue 
becomes whether or or not it is worth adding yet another command to Pine 
to do an operation that users can already do themselves....  ;-)

---

From: Ian Dunkin <[email-masked]>
Date: Fri, 28 Jan 1994 19:19:45 +0000 (GMT)

> the appropriate commands in Pine, or by exiting Pine and running it again.

Thanks for the reply..  Err.. I can see this should be obvious, but:  What
_are_ the `appropriate commands' in Pine, to do this??  Leaving and Going 
back to the INBOX again still seems to keep the cached snapshot... 

  I.

---

From: David L Miller <[email-masked]>
Date: Fri, 28 Jan 1994 12:58:30 -0800 (PST)

The INBOX is the one folder that there is no way to recover without
exiting and re-entering pine.  This is a side effect of never closing the 
INBOX in routine operation.

|\ |  |\/|  David L. Miller    [email-masked]  (206) 685-6240
|/ |_ |  |  Software Engineer, Pine Development Team   (206) 685-4045 (FAX)
University of Washington, Networks & Distributed Computing
4545 15th Ave NE, Seattle WA 98105, USA