Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!ccu.umanitoba.ca!herald.usask.ca!telepro!oliphant
From: oliphant@telepro.UUCP (Mike Oliphant)
Newsgroups: comp.sys.amiga.programmer
Subject: Re:  Question on AbortIO() and WaitIO()
Message-ID: <oliphant.8324@telepro.UUCP>
Date: 24 May 91 05:31:31 GMT
References: <28630@uflorida.cis.ufl.EDU> <21757@cbmvax.commodore.com>
Organization: TelePro Technologies
Lines: 40

In article <21757@cbmvax.commodore.com> carolyn@cbmvax.commodore.com (Carolyn Scheppner - CATS) writes:

>If you KNOW there is an outstanding request, I believe the best
>action is:
>
>if(!CheckIO(ioreq))	AbortIO(ioreq);
>WaitIO(ioreq);

The CheckIO() is  EXTREMELY important with the A2232 serial card - it doesn't
like you aborting requests that have been satisfied.  In fact, it seems that
even the CheckIO() safety measure is not enough with this card.  I've found
this method solves the problem:

  NiceAbort(ioreq)
  struct IORequest *ioreq;
  {
    Forbid();
    if(!CheckIO(ioreq)) AbortIO(ioreq);
    Permit();
    WaitIO(ioreq);
  }

A program called 'A2232Patch' by Reid Bishop uses SetFunction() to turn
all AbortIO() calls into NiceAborts.  Without this patch, doing complex
things with the serial port (such as spawning a BBS from a front-end
FidoNet mailer) is likely to fail miserably on the A2232 (unless the software
in question does NiceAborts itself).

Hopefully, this bug in the A2232 will be fixed (the standard serial.device
has no such problem) and these contortions will be rendered unneccesary.

--
Mike Oliphant	telepro!oliphant@herald.usask.ca or herald!telepro!oliphant
		FidoNet: (1:140/91) - ZMH only
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