Subject: Re: Cygwin patches for 2002e

From: Gregory Hicks <[email-masked]>
Date: Wed, 22 Oct 2003 11:22:53 -0700 (PDT)

Eduardo:

I think what Mark was saying was that simultaneous access to an mbx
mailbox from various incarnations of pine MAY not work correctly under
an MS-DOS implementation of windows.

If only one incarnation of pine is running, the mbx SHOULD be readable.

If your users *insist* on running two or more incarnations of pine to
access the same mailbox, the results probably will be unpredictable.

Regards,
Gregory Hicks

> Date: Wed, 22 Oct 2003 10:52:22 -0700 (PDT)
> From: Eduardo Chappa <[email-masked]>
> To: Mark Crispin <[email-masked]>
> Cc: Abe Backus <[email-masked]>, [email-masked]
> Subject: Re: Cygwin patches for 2002e
> 
> *** Mark Crispin ([email-masked]) wrote today:
> 
> :) On Wed, 22 Oct 2003, Eduardo Chappa wrote:
> :) > There is no way I can predict what a user will do when using Pine,
> :) > and you must know very well that ignoring a possible case is one of
> :) > the main reasons why users report bugs, so I would like to offer a
> :) > full featured (or as much complete as possible)  software for people
> :) > in Cygwin. This means that if they want simultaneous access to a
> :) > mailbox, they'll need to get it if the format of the mailbox allows
> :) > it.
> :)
> :) Once again...
> :)
> :) Simultaneous access in the mbx format requires meaningful file locking.
> :)
> :) There is no such thing as meaningful file locking in Windows 98.
> :) Windows 98 is not a real operating system.  Nor are Windows 95, Windows
> :) Me, Windows 3.1, MS-DOS, Mac OS 9 (and earlier), etc.
> 
> Mark,
> 
>   Does this mean that the changes that you are accepting into C-client
> will make Pine not work in Windows 9X when using mbx style folders?. I
> believe you are trying to say that, but it is not completely clear. Your
> answer is about locking, not about mbx style folders. I just want to be
> sure that the answer to my question is yes. Can you confirm or deny this,
> please?
> 
> Thanks. Have a nice day.
> 
> Eduardo
> http://www.math.washington.edu/~chappa/pine/

-------------------------------------------------------------------
Gregory Hicks                        | Principal Systems Engineer
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When a team of dedicated individuals makes a commitment to act as
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States Navy

---

From: Eduardo Chappa <[email-masked]>
Date: Wed, 22 Oct 2003 11:32:23 -0700 (PDT)

*** Gregory Hicks ([email-masked]) wrote today:

:) I think what Mark was saying was that simultaneous access to an mbx
:) mailbox from various incarnations of pine MAY not work correctly under
:) an MS-DOS implementation of windows.
:)
:) If only one incarnation of pine is running, the mbx SHOULD be readable.
:)
:) If your users *insist* on running two or more incarnations of pine to
:) access the same mailbox, the results probably will be unpredictable.

Dear Gregory,

  Thank you for clarifying Mark's message. So the answer translated to my
mind is no it will not work. Too bad. Hopefully it will not be a problem.

  Thank you!

Eduardo

---

From: Mark Crispin <[email-masked]>
Date: Wed, 22 Oct 2003 12:01:16 -0700 (PDT)

> access the same mailbox, the results probably will be unpredictable.

This is correct.  To be specific:

If you wish to run two or more incarnations of Pine (or other c-client
tool such as imapd) on Windows to access the same mailbox at the same
time, the only means that is promised to work correctly is with a native
Windows (not Cygwin) version, running under Windows NT/2000/XP.

It is probable (but not guaranteed) that two or more incarnations of a
Cygwin build of UNIX Pine (or other c-client software) accessing the same
mailbox at the same time will work correctly under Windows NT/2000/XP.

In any other configuration, the results will be unpredictable, including
*all* configurations involving Windows 3.1/9x/Me (MS-DOS based Windows).

It is possible (but not guaranteed) that a Cygwin build of UNIX Pine (or
other c-client software) accessing the same mailbox at the same time with
PC Pine (or other native Windows build c-client software) accessing the
same mailbox at the same time will work to a limited fashion under Windows
NT/2000/XP. Certain aspects will fail; auxillary locks are handled
differently in UNIX and Windows.

The lessons should be:
 1) do not expect simultaneous access to work on systems which do not
     provide the tools to make simultaneous access work.
 2) do not expect software running under a compatibility package for
     a different operating system to interact completely (if at all)
     with the native version of that software.

A compatibility package should be seen for what it is -- an interim means
to run software from a foreign operating system.  As such, it will have
limitations; and these limitations translate into permanent restrictions
on how the software runs under that compatibility package.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.