Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!brutus.cs.uiuc.edu!apple!jdevoto
From: jdevoto@Apple.COM (Jeanne A. E. DeVoto)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Communications Toolbox
Message-ID: <36057@apple.Apple.COM>
Date: 30 Oct 89 23:08:20 GMT
References: <1174@cnetlu.UUCP>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 39

[really from austing@apple.com]

In article <1174@cnetlu.UUCP> ranson@cnetlu.UUCP (Ranson) writes:
>
>How does one do asynchronous calls to the Connection Manager?
>The docs I have (Inside Special K) give a weird description of the
>completion routines. They are passed a Connection HANDLE. Of course,
>a handle may not be valid at completion time, so there is a warning
>saying that the handle may be NIL. There is also a sentence about a
>(undescribed) parameter block pointed to by A0, but that may also not
>be available.
>With this essentially parameter-less completion routine, I can see no
>way to have several asynchronous calls pending at the same time (at
>least one per connection would be useful). Am I missing something?

Simple, just call it asynchronously.  You don't *HAVE* to supply a completion
routine to the call, just pass it as a NIL.  However, if you are intending
to do async Connection Manager calls, the first thing you should do after
a CMNew (or CMChoose) is do a MoveHHi and HLock of the Connection Handle.  I've
been using the toolbox asynchronously (and successfully) for over 4 months with
no problems.
The parameter block pointed to by A0 is a device manager param block.  If your
tool supports it (and it should), then you can get the device manager info.
However, since I don't really care (right now) what the device manager says, I
don't use it.
In summary, if you want to use the Connection Manager asynchronously, lock the
Connection Handle.  Because the tool's completion routine (and yours) could be
called during interrupt, you *MUST* follow the guidelines for accessing 
handles during an interrupt.

     -Glenn L. Austin
      CommToolbox Pickup Artist
-- 
====== jeanne a. e. devoto ========================================
 jdevoto@apple.com  |  You may not distribute this article under a
 jdevoto@well.UUCP  |  compilation copyright without my permission.
___________________________________________________________________
 Apple Computer and I are not authorized  |        CI$: 72411,165
 to speak for each other.                 |  AppleLink: SQA.TEST