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- Path: sparky!uunet!dtix!darwin.sura.net!jvnc.net!yale.edu!ira.uka.de!chx400!josef!blatter
- From: blatter@ifi.unizh.ch (Martin A. Blatter)
- Newsgroups: comp.sys.amiga.applications
- Subject: Re: Virtual Memory for the Amiga?
- Message-ID: <1992Jul27.162827.1752@ifi.unizh.ch>
- Date: 27 Jul 92 16:28:27 GMT
- References: <1992Jul27.101544.3547@mpifr-bonn.mpg.de> <1992Jul27.123455.8577@pixel.kodak.com>
- Organization: University of Zurich, Department of Computer Science
- Lines: 43
-
- In article <1992Jul27.123455.8577@pixel.kodak.com> jeh@raster.kodak.com (Ed Hanway) writes:
- >Would someone with this virtual memory system care to try the following
- >program?
- [...`buf' has previously been allocated as virtual memory...]
- > Disable();
- > buf[addr]++;
- > Enable();
- [...]
-
- There's no need to check that program because it *will* not work with
- virtual memory (the reason should be pretty clear, see below). However,
- the program could nevertheless be used on a system with GigaMem, since
- the supplied preferences editor allows you to individually remove or add
- programs from/to the list of VMem-compatible programs. As my experience
- shows, there's almost no commercial application which has problems
- with Virtual Memory. By the way: GigaMem will not crash your machine
- in such cases but rather pop up a `Software Error' requester...
-
- The following lines are from the documentation of the vmem.library
- where the author describes some restrictions which are caused by the
- nature of virtual memory (and not this specific implementation):
-
- 2) Memory allocated via any call of vmem.library MUST NOT be accessed
- while Disable(), Forbid() or made available to any task other than
- the one which did the allocation. This includes message ports,
- semaphores, public lists or list entries, IO requests, interrupt
- structures etc.
-
- ...and this one's from the Disable() autodoc:
-
- DO NOT USE THIS CALL WITHOUT GOOD JUSTIFICATION. THIS CALL IS
- VERY DANGEROUS!
-
- Think twice before using Disable(), then think once more.
- After all that, think again.
-
- >Ed Hanway --- jeh@raster.kodak.com
-
- --
- -------------------------------------------------------------------------
- Martin A. Blatter blatter@amiga.physik.unizh.ch
- Any sufficiently advanced bug is indistinguishable from a feature.
- -- Rich Kulawiec
-