From:	eplmst AT lu DOT erisoft DOT se (Martin Stromberg)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Problems using signals
Date:	10 Oct 1999 16:22:56 GMT
Organization:	Ericsson Erisoft AB, Sweden
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Eli Zaretskii (eliz AT is DOT elta DOT co DOT il) wrote:
: The way it works is as follows.  The keyboard interrupt handler
: invalidates the DS selector by resetting its limit to the first page
: (a.k.a. null page) only, saves the original limit in a special
: variable, sets a flag which indicates that Ctrl-C was seen, and then
: does an IRET.  Since all data is above the null page, we are
: guaranteed that the first time the program touches any of its data, it
: will trigger a GPF.  The GPF exception handler, also set up by the
: startup code, sees that the exception is really a fake one generated
: by Ctrl-C, so it restores the DS limit to its original value and then
: does a "raise(SIGINT);".

Nice explanation, but how can this work in WINDOZE where there isn't any
NULL page?


Nyman, The Piano Concerto,

							MartinS

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