Question on how to implement exclusive scheduling

[Chris Torek]

Note, however, that implementing arbitrary mandatory locking is not
a good idea as anyone can then write something like this:

	#include <signal.h>

	main() {
		int fd, i;

		for (i = 0; i < 31; i++)
			(void) signal(i, SIG_IGN);
		fd = open("/etc/passwd", 0);
		lockf(fd, -1);	/* lock it to EOF */
		pause();	/* or, for(;;); is even more malicious */
	}

If there are no system administrators already logged in you may
have to halt the machine from the console.

There are numerous ways around this, the easiest probably being to
use advisory locks rather than mandatory locks.
-- 
(This mind accidently left blank.)

In-Real-Life: Chris Torek, Univ of MD Comp Sci (301) 454-7690
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