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From: david@walking.pub.uu.oz.au (David Le Blanc)
Newsgroups: comp.sys.amiga.programmer
Subject: Can you call DeviceProc() from a Task?
Keywords: DeviceProc() dos.library dos process
Message-ID: <6101@walking.pub.uu.oz.au>
Date: 18 Jun 91 08:12:58 GMT
Organization: Not an Organisation.
Lines: 35

I would like to know if DeviceProc() and IoErr() can be called from a task?

DeviceProc() does not seem to be like 'Read()' in that it does not use
messages to accomplish its task. (Ie, it goes to the DOS list to find the
process)

How about IoErr()? Where does it find its Error code? I am pretty sure it
goes to PROCESS->pr_Result2, in which case NO you can't use it in a task.

Now, since DeviceProc returns a lock in IoErr(), does it need to be called from
a Task?

The reason I would like to know is: I am (pretending) to write a handler,
which I am fairly certain is a DOS process (bit silly otherwise) however
I understand the calling DOS from that context is BAD since while DOS is
waiting on your pr_MsgPort for a reply to its 'Read()' or whatever,
another process may just send you a message, which usually causes some
sort of GURU (AsyncPkt usually).

Now, are there some 'clean' things I can call? Like IoErr(), DeviceProc()
etc? I am only worried because MOST dos calls can be done via a 
'struct StandardPacket' with appropriate filler material, however
DeviceProc() would require me to manually scan DOS Lists, which I would
rather not do. (It is SUPPOSED to be a black box isnt it?)

Cheers!
	David

--
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   David Le Blanc    UUCP (home)   : david@walking.pub.uu.oz.au
   david@walking     ACSNET (work) : david@dogmelb.mlb.geomechanics.csiro.au
 - CSIRO Division of Geomechanics - Fragment analysis and 3D Fractal imaging -
          "What do you mean officer? This bike can't GO 140 km/h"
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