/**/
+/*
+ * This is used to avoid floating point rounding problems.
+ * It is added to ev_rt_now when scheduling periodics
+ * to ensure progress, time-wise, even when rounding
+ * errors are against us.
+ * This value is good at least till the year 4000.
+ * Better solutions welcome.
+ */
+#define TIME_EPSILON 0.0001220703125 /* 1/8192 */
+
#define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */
#define MAX_BLOCKTIME 59.743 /* never wait longer than this time (to detect time jumps) */
-/*#define CLEANUP_INTERVAL (MAX_BLOCKTIME * 5.) /* how often to try to free memory and re-check fds */
+/*#define CLEANUP_INTERVAL (MAX_BLOCKTIME * 5.) /* how often to try to free memory and re-check fds, TODO */
#if __GNUC__ >= 3
# define expect(expr,value) __builtin_expect ((expr),(value))
/* first reschedule or stop timer */
if (w->reschedule_cb)
{
- ((WT)w)->at = w->reschedule_cb (w, ev_rt_now + 0.0001);
+ ((WT)w)->at = w->reschedule_cb (w, ev_rt_now + TIME_EPSILON);
assert (("ev_periodic reschedule callback returned time in the past", ((WT)w)->at > ev_rt_now));
downheap ((WT *)periodics, periodiccnt, 0);
}
else if (w->interval)
{
- ((WT)w)->at = w->offset + floor ((ev_rt_now - w->offset) / w->interval + 1.) * w->interval;
+ ((WT)w)->at = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
+ if (((WT)w)->at - ev_rt_now <= TIME_EPSILON) ((WT)w)->at += w->interval;
assert (("ev_periodic timeout in the past detected while processing timers, negative interval?", ((WT)w)->at > ev_rt_now));
downheap ((WT *)periodics, periodiccnt, 0);
}
}
#endif
-int inline_size
-time_update_monotonic (EV_P)
-{
- mn_now = get_clock ();
-
- if (expect_true (mn_now - now_floor < MIN_TIMEJUMP * .5))
- {
- ev_rt_now = rtmn_diff + mn_now;
- return 0;
- }
- else
- {
- now_floor = mn_now;
- ev_rt_now = ev_time ();
- return 1;
- }
-}
-
-void inline_size
-time_update (EV_P)
+void inline_speed
+time_update (EV_P_ ev_tstamp max_block)
{
int i;
#if EV_USE_MONOTONIC
if (expect_true (have_monotonic))
{
- if (time_update_monotonic (EV_A))
+ ev_tstamp odiff = rtmn_diff;
+
+ mn_now = get_clock ();
+
+ /* only fetch the realtime clock every 0.5*MIN_TIMEJUMP seconds */
+ /* interpolate in the meantime */
+ if (expect_true (mn_now - now_floor < MIN_TIMEJUMP * .5))
{
- ev_tstamp odiff = rtmn_diff;
-
- /* loop a few times, before making important decisions.
- * on the choice of "4": one iteration isn't enough,
- * in case we get preempted during the calls to
- * ev_time and get_clock. a second call is almost guaranteed
- * to succeed in that case, though. and looping a few more times
- * doesn't hurt either as we only do this on time-jumps or
- * in the unlikely event of having been preempted here.
- */
- for (i = 4; --i; )
- {
- rtmn_diff = ev_rt_now - mn_now;
+ ev_rt_now = rtmn_diff + mn_now;
+ return;
+ }
+
+ now_floor = mn_now;
+ ev_rt_now = ev_time ();
- if (fabs (odiff - rtmn_diff) < MIN_TIMEJUMP)
- return; /* all is well */
+ /* loop a few times, before making important decisions.
+ * on the choice of "4": one iteration isn't enough,
+ * in case we get preempted during the calls to
+ * ev_time and get_clock. a second call is almost guaranteed
+ * to succeed in that case, though. and looping a few more times
+ * doesn't hurt either as we only do this on time-jumps or
+ * in the unlikely event of having been preempted here.
+ */
+ for (i = 4; --i; )
+ {
+ rtmn_diff = ev_rt_now - mn_now;
- ev_rt_now = ev_time ();
- mn_now = get_clock ();
- now_floor = mn_now;
- }
+ if (fabs (odiff - rtmn_diff) < MIN_TIMEJUMP)
+ return; /* all is well */
+
+ ev_rt_now = ev_time ();
+ mn_now = get_clock ();
+ now_floor = mn_now;
+ }
# if EV_PERIODIC_ENABLE
- periodics_reschedule (EV_A);
+ periodics_reschedule (EV_A);
# endif
- /* no timer adjustment, as the monotonic clock doesn't jump */
- /* timers_reschedule (EV_A_ rtmn_diff - odiff) */
- }
+ /* no timer adjustment, as the monotonic clock doesn't jump */
+ /* timers_reschedule (EV_A_ rtmn_diff - odiff) */
}
else
#endif
{
ev_rt_now = ev_time ();
- if (expect_false (mn_now > ev_rt_now || mn_now < ev_rt_now - MAX_BLOCKTIME - MIN_TIMEJUMP))
+ if (expect_false (mn_now > ev_rt_now || ev_rt_now > mn_now + max_block + MIN_TIMEJUMP))
{
#if EV_PERIODIC_ENABLE
periodics_reschedule (EV_A);
#endif
-
/* adjust timers. this is easy, as the offset is the same for all of them */
for (i = 0; i < timercnt; ++i)
((WT)timers [i])->at += ev_rt_now - mn_now;
else
{
/* update time to cancel out callback processing overhead */
-#if EV_USE_MONOTONIC
- if (expect_true (have_monotonic))
- time_update_monotonic (EV_A);
- else
-#endif
- {
- ev_rt_now = ev_time ();
- mn_now = ev_rt_now;
- }
+ time_update (EV_A_ 1e100);
block = MAX_BLOCKTIME;
++loop_count;
backend_poll (EV_A_ block);
- }
- /* update ev_rt_now, do magic */
- time_update (EV_A);
+ /* update ev_rt_now, do magic */
+ time_update (EV_A_ block);
+ }
/* queue pending timers and reschedule them */
timers_reify (EV_A); /* relative timers called last */
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