ack/lang/cem/libcc/gen/sleep.c

/* $Header$ */
#include <signal.h>
#include <setjmp.h>

static jmp_buf	setjmpbuf;

static void
alfun(){
	longjmp(setjmpbuf, 1);
}		/* used with sleep() below */

sleep(n)
	int n;
{
/* sleep(n) pauses for 'n' seconds by scheduling an alarm interrupt. */
	unsigned oldalarm;
	void (*oldsig)();

  if (n <= 0) return;
  if (setjmp(setjmpbuf)) {
	signal(SIGALRM, oldsig);
	alarm(oldalarm);
	return;
  }
  oldalarm = alarm(5000);	/* Who cares how long, as long as it is long
				   enough
				*/
  if (oldalarm > n) oldalarm -= n;
  else if (oldalarm) {
		n = oldalarm;
		oldalarm = 1;
  }
  oldsig = signal(SIGALRM, alfun);
  alarm(n);
  for (;;)  {
	/* allow for other handlers ... */
	pause();
  }
}