From:	Shawn Hargreaves <Shawn AT talula DOT demon DOT co DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: dosmemget and memcpy inside an interrupt handler
Date:	Thu, 11 Jun 1998 20:46:37 +0100
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Message-ID:	<R+1jFFAdQDg1Ewc+@talula.demon.co.uk>
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To:	djgpp AT delorie DOT com
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Eli Zaretskii writes:
>>   May I have problems if I use 'dosmemget' or 'memcpy' functions inside
>> the Packet Driver software interrupt handler?
>
>The only consideration is that you should lock all the memory that is 
>involved in moving the data by either of these two functions.  Other than 
>that, you should be fine.

Indeed, but it isn't so easy to lock the code of a libc function. You
could set the CRT0 flags to lock all memory, but that isn't a very
polite thing to do. A better option would be to copy the relevant code
from the libc sources, and insert it into your own code so that you will
know for sure how big it is and exactly what other routines it might
call.

But the original poster was asking about a _software_ interrupt handler:
my understanding is that you don't actually need to lock the memory used
by these, as long as they can only be called by user level programs and
not by DOS itself...


--
Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/
"Miracles are nothing if you've got the wrong intentions" - Mike Keneally

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