[comp.sys.mac.programmer] _OSDispatch

awd@dbase.UUCP (Alastair Dallas) (11/21/89)

Can anyone tell me what OSDispatch is supposed to do?  I'm tracing
through some code and I'm forced to guess what's going on behind
this closed door.  I gather from tech note #180's brief mention
that it has something to do with MultiFinder and memory allocation.
It takes an int selector code < $20 (it seems) and I found a table
of addresses followed by two shorts that might have been size of
parameter, size of return value.

Any pointers would be appreciated.  I don't have any MultiFinder
documentation (except tech notes), so that might be all I need.

/alastair/

andyp@gvgpvd.GVG.TEK.COM (Andy Peterman) (11/21/89)

In article <306@dbase.UUCP> awd@dbase.UUCP (Alastair Dallas) writes:
>Can anyone tell me what OSDispatch is supposed to do?  I'm tracing
>through some code and I'm forced to guess what's going on behind
>this closed door.  I gather from tech note #180's brief mention
>that it has something to do with MultiFinder and memory allocation.
>It takes an int selector code < $20 (it seems) and I found a table
>of addresses followed by two shorts that might have been size of
>parameter, size of return value.

The _OSDispatch routines are system calls to MultiFinder.  Some of these
are documented in the Programmer's Guide to MultiFinder available from
APDA.  These functions (the ones that Apple admits to) deal with memory
allocation from the MultiFinder memory.  There are others that are
used internally by Apple products (Finder and Sade, for example) that
can access information about all applications that are running under
MultiFinder.  System 7.0 preliminary documentation hints that these will
be available then (meaning they will finally be documented).  If you can't
wait for System 7.0, check out the article in Autumn '89 MacTech
Quarterly (page 25).  This has a totally unofficial explanation of many
of these other functions.  Use at your own risk!

	Andy Peterman

chewy@apple.com (Paul Snively) (11/22/89)

In article <1333@gvgpvd.GVG.TEK.COM> andyp@gvgpvd.GVG.TEK.COM (Andy 
Peterman) writes:
> System 7.0 preliminary documentation hints that these will
> be available then (meaning they will finally be documented).  If you 
can't
> wait for System 7.0, check out the article in Autumn '89 MacTech
> Quarterly (page 25).  This has a totally unofficial explanation of many
> of these other functions.  Use at your own risk!
> 
>         Andy Peterman

Thanks for doing my job for me! ;-)

Seriously, I can categorically tell you here and now that the information 
in the MacTech Quarterly IS out of date with respect to System 7.0's 
MultiFinder.  The bottom line?  If you're gonna use it, be sure to check 
for the version of MultiFinder that it documents.

__________________________________________________________________________
Just because I work for Apple Computer, Inc. doesn't mean that they 
believe what I believe or vice-versa.
__________________________________________________________________________
C++ -- The language in which only friends can access your private members.
__________________________________________________________________________

levin@bbn.com (Joel B Levin) (11/22/89)

In article <306@dbase.UUCP> awd@dbase.UUCP (Alastair Dallas) writes:
|Can anyone tell me what OSDispatch is supposed to do?  . . .
|
|Any pointers would be appreciated.  I don't have any MultiFinder
|documentation (except tech notes), so that might be all I need.

That's exactly right.  The MultiFinder documentation available from
APDA ($10 or $20) has this stuff in it.

	/JBL
=
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