Path: utzoo!attcan!utgpu!watmath!watcgl!electro!ignac
From: ignac@electro.UUCP (Ignac Kolenko)
Newsgroups: comp.sys.atari.st
Subject: Re: Communicating with Desk Accessories
Message-ID: <510@electro.UUCP>
Date: 15 Jun 89 00:48:07 GMT
References: <8660@chinet.chi.il.us> <507@electro.UUCP> <1553@atari.UUCP>
Reply-To: ignac@electro.UUCP (Ignac Kolenko)
Organization: Electrohome Ltd., Kitchener, ON
Lines: 62

In article <1553@atari.UUCP> kbad@atari.UUCP (Ken Badertscher) writes:
>An AC_CLOSE message means that any resources that your accessory has
>open are about to go away.  Namely, any open files will be closed,
>Malloc'ed memory will be released, etc.  Anything that your accessory
>sets up while a program is running has a potential for vanishing when
>the program terminates.  AC_CLOSE is the system's way of warning
>accessories about programs terminating.




lets say that my accessory requested memory before a program loads. what i mean
is that my accessory gets memory while the normal system desktop is displayed.
Malloc returns a pointer to the memory, and i go and use it for whatever i like.
now, a program loads from the desktop. my accessory gets an AC_CLOSE message.
does this mean that the memory i allocated above is not mine anymore???
if so, yikes!!         :-(    :-(
if not, what happens in this case??????




>As far as memory-gobbling is concerned, this is unfortunately how the
>system works.  Whenever you switch resolutions, accessories get
>re-loaded, and the old ones just hang around using memory.  This is a
>side effect of the way the AES treats res changes: not-quite-
>a-warmboot.  Offhand, I can't think of any quick and easy ways around
>it.  I usually use warmboots to switch resolution ;-).

thats pretty weird. if i load a well behaved (or so i hope) accessory like
the control panel (from atari) right from a cold boot, and search through
memory using templmon for the text used in the menu_register() call, i can
find only one reference to it. fine. there should only be one copy of it in
memory at this time. now when i change resolutions, and search memory again
for that same string pattern, i still only find one copy of it in memory.
and i always assumed that that was the proper way for an accessory to work.
(once i find that string in memory, a little bit of dissasembling in that 
area allows me to locate the main loop for the event dispatching, which i
use as proof that there is only one copy in memory at this time)

now when i load one of my accessories that i have written right from a cold
boot, and search for the text for the menu_register call, i again find only
one copy as i expected i would. now, if i change resolutions, and search again,
i find TWO copies of the accessory in memory. and only on MY bloody 
accessories!!!!!!!!!!

so, after all this rambling, i ask, is there any special clean up that i
should do after getting a AC_CLOSE message. you mention things like memory
get re-allocated, etc. should i always free memory at this time. should i 
close files that i had open, or will the system take care of that for me??
what other resources should i let go??

anyways, thanx for the info so far. it allows me to continue to "go where
no atari programmer has gone before ..." (ok, so during midterms i get a bit
melodramatic)         :-)


-- 
Ignac A. Kolenko (The Ig)          watmath!watcgl!electro!ignac      

"Catholic or Protestant, you got no choice. I tried to scream, but I lost
my voice!" from 'Irish Eyes Don't Smile Tonight' by SUBURBAN DISTORTION