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From: Adam David <adam@veda.is>
Message-Id: <199607202348.XAA06918@veda.is>
Subject: missed SIGALRM
To: freebsd-current@freebsd.org
Date: Sat, 20 Jul 1996 23:48:22 +0000 (GMT)
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I have noticed that a SIGALRM can sometimes be missed altogether under certain
conditions, perhaps as a side-effect of heavy machine load. I am looking into
this problem, and any other datapoints/suggestions are welcome. The following
program (in its more complete version) stops doing its stuff once in a while
(typically once a day or more often) and needs to be restarted as a result.
The likelihood of this occuring seems related to periods of heavy system load.

int tick;

handler() { tick = 1; }

set_tick() {
	tick = 0;
	signal(SIGALRM, handler);
	alarm(1);
}

get_tick() { return tick; }

main() {
	set_tick();
	for (;;) {
		if (get_tick()) {
			/* do stuff */
			set_tick();
		}
	}
}

--
Adam David <adam@veda.is>