+(defun timer-next-integral-multiple-of-time (time secs)
+ "Yield the next value after TIME that is an integral multiple of SECS.
+More precisely, the next value, after TIME, that is an integral multiple
+of SECS seconds since the epoch. SECS may be a fraction."
+ (let ((time-base (ash 1 16)))
+ (if (fboundp 'atan)
+ ;; Use floating point, taking care to not lose precision.
+ (let* ((float-time-base (float time-base))
+ (million 1000000.0)
+ (time-usec (+ (* million
+ (+ (* float-time-base (nth 0 time))
+ (nth 1 time)))
+ (nth 2 time)))
+ (secs-usec (* million secs))
+ (mod-usec (mod time-usec secs-usec))
+ (next-usec (+ (- time-usec mod-usec) secs-usec))
+ (time-base-million (* float-time-base million)))
+ (list (floor next-usec time-base-million)
+ (floor (mod next-usec time-base-million) million)
+ (floor (mod next-usec million))))
+ ;; Floating point is not supported.
+ ;; Use integer arithmetic, avoiding overflow if possible.
+ (let* ((mod-sec (mod (+ (* (mod time-base secs)
+ (mod (nth 0 time) secs))
+ (nth 1 time))
+ secs))
+ (next-1-sec (+ (- (nth 1 time) mod-sec) secs)))
+ (list (+ (nth 0 time) (floor next-1-sec time-base))
+ (mod next-1-sec time-base)
+ 0)))))
+