Path: utzoo!attcan!uunet!sjsca4!news
From: enk@corona (Edan Kabatchnik)
Newsgroups: comp.sys.mac
Subject: Re: Hey Apple Mac engineers, answer->Ma
Message-ID: <1989Aug15.001507.14552@sj.ate.slb.com>
Date: 15 Aug 89 00:15:07 GMT
References: <14845@dartvax.Dartmouth.EDU> <46100321@uxe.cso.uiuc.edu>
Sender: enk@slcs.slb.com (Edan Kabatchnik)
Reply-To: enk@slcs.slb.com (Edan Kabatchnik)
Organization: Schlumberger Technlogies ATE, San Jose, CA
              Massachusetts Institute of Technology, Cambridge, MA
Lines: 50

In some article about Multifinder vs. Multitasking, someone writes:

>>      This not a fault of the Mac, but of the programmer who programmed
>> the dialog.  Mac dialogs can be set up to be totally modal, as you
>> describe, or to be modeless, i.e. just like any other window.  It is
>> more work for the programmer to write programs which use modeless
>> dialogs, not much more work, but a little more.  It is modal dialogs,
>> not dialogs per se, which lock you out under MultiFinder, and 99% of
>> the time, you have some lazy application programmer to thank for it.

> It is a fault of the operating system. In a true multitasking
> system, it is IMPOSSIBLE for one program to lock up the system,
> whether intentionally or because of a bug.

     This is just not the case.  Here are two examples:

	1) Gnumacstool running on the Sun Workstation: when one hits the right
menu button quickly and releases it, the Emacs Menu comes up.  User input
cannot be sent anywhere until the menu is dismissed.

	2) Framemaker running on the Sun Workstation: when Frame Maker's modal
dialogs appear for things like "OK to Quit Frame Maker?" the modal dialog must
be dismissed until the user can direct any of his or her input to another
process.

     At this point, one might argue that "Yes, but other windows (i.e.
processes) can continue to carry out any task not related to user input,
e.g. a compilation."  This is also true for the Macintosh.  Take TOPS for
example.  TOPS can service a remote disk access while a modal dialog is up or
while a menu selection is being made.

     The Macintosh is not a true multitasking system from the perspective of a
programmer, not the user: a programmer wishing to write a "multitasking"
application under Macintosh OS must take great care to write his program
carefully.  On a UNIX system, the programmer simply has an easier time writing
a such a program.  The user, however, can observe the effects of multitasking
under Macintosh OS just as easily as he can under UNIX: if the programmer who
wrote the applications he or she is using spent the time to develop them
properly, the user is rewarded with the benefit of multitasking.  The problem
is that every application you use must be written properly in order for the
whole system to multitask properly.

+----------------------------------------------------+-------------------------+
|There is a club if you would like to go.            |     Edan Kabatchnik     |
|You could meet somebody who really loves you.       +-------------------------+
|So you go, and you stand on your own.               |           MIT           |
|And you leave on your own.                          | enk@wheaties.ai.mit.edu |
|And you go home, and you cry, and you want to die.  |Schlumberger Technologies|
|                                   - The Smiths     |    enk@slcs.slb.com     |
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