Manual Reference Pages - VGA_SAFETY_FORK (3)
vga_safety_fork - start a parallel process to restore the console at a crash
void vga_safety_fork(void (*shutdown_routine)(void))
Calling this at the start of a program results in a better
chance of textmode being restored in case of a crash.
However it has to raise the iopl level to 3 to work. This is
a small security breach as it is inherited to any programs
you fork of. However, some SVGA card drivers have to use
If you use it call that function as the very first
vga_ function. Call it right before
vga_init (3). Note that
vga_safety_fork() will already enter a graphicsmode. (For font
and grafix state saving).
Dont overestimate the power of this function. Your application will continue to run
in background while a foreground application will restore a usable screen and graphics
mode in case of a crash.
demo shows the principal operation.
(*shutdown_routine)() is called when the system crashes. However, realize that the call will take in a forked
copy of your program, youll not have access to any globals modified after the
This manual page was edited by Michael Weller <firstname.lastname@example.org>. The
exact source of the referenced function as well as of the original documentation is
It is very likely that both are at least to some extent are due to
Harm Hanemaayer <H.Hanemaayer@inter.nl.net>.
Occasionally this might be wrong. I hereby
asked to be excused by the original author and will happily accept any additions or corrections
to this first version of the svgalib manual.
|Svgalib (>= 1.2.11) ||VGA_SAFETY_FORK (3) ||27 July 1997 |
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