Xref: news-dnh.mv.net comp.os.msdos.djgpp:1636
Path: news-dnh.mv.net!mv!news.sprintlink.net!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!lerc.nasa.gov!lerc.nasa.gov!babar
From: gantose AT lerc DOT nasa DOT gov (Dave Gantose)
Newsgroups: comp.os.msdos.djgpp
Subject: Please define "locking"
Date: Fri, 18 Aug 95 18:03:11 GMT
Organization: ADF, Inc.--NASA Lewis, Cleveland, OH
Lines: 24
Nntp-Posting-Host: babar.lerc.nasa.gov
Keywords: locking paging interrupts
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Dj-Gateway: from newsgroup comp.os.msdos.djgpp

I have had occasion lately to write two different interrupt handlers: one for 
serial i/o and one to make the system timer tick at 64Hz. Both were done 
originally using V1, and both have been converted to V2. They seem to work OK, 
though the serial communications loses a byte here and there at any baud rate 
above 6600.

Anyway, I've noticed that several recent posts about interrupts (dpmi, go32, 
etc.) have talked about "locking" parts of code, writing the interrupt 
handlers in GAS so as to handle the locking better, etc. What does this mean? 
And, how is it related to "paging"--another subject I know little about? Like 
I said above, I wrote a couple generally successful interrupt routines without 
knowing this, and I wonder if they are just accidents waiting to happen?

I realize these may be complex, low-level subjects not quickly explainable, 
but I would appreciate it if someone could please give me a start and/or point 
me to an in-depth (yet understandable) resource?

Thanks for your help.

=============================================================================
Dave Gantose
ADF, Inc.
2001 Aerospace Pkwy.           phone: (216)977-1376
Brook Park, OH  44142          email: Gantose AT lerc DOT nasa DOT gov