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-rw-r--r--Changes4
-rw-r--r--ev.c105
2 files changed, 60 insertions, 49 deletions
diff --git a/Changes b/Changes
index f5f0800..449eea7 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,9 @@
Revision history for libev, a high-performance and full-featured event loop.
+ - use 1-based heaps, simplifies code, reduces codesize, makes
+ for better cache-efficiency and increases memory requirements
+ by up to two pointers/loop.
+
3.31 Wed Apr 16 20:45:04 CEST 2008
- added last minute fix for ev_poll.c by Brandon Black.
diff --git a/ev.c b/ev.c
index ca40e18..634c079 100644
--- a/ev.c
+++ b/ev.c
@@ -327,6 +327,8 @@ typedef ev_watcher *W;
typedef ev_watcher_list *WL;
typedef ev_watcher_time *WT;
+#define ev_at(w) ((WT)(w))->at
+
#if EV_USE_MONOTONIC
/* sig_atomic_t is used to avoid per-thread variables or locking but still */
/* giving it a reasonably high chance of working on typical architetcures */
@@ -762,20 +764,21 @@ upheap (WT *heap, int k)
{
WT w = heap [k];
- while (k)
+ for (;;)
{
- int p = (k - 1) >> 1;
+ int p = k >> 1;
- if (heap [p]->at <= w->at)
+ /* maybe we could use a dummy element at heap [0]? */
+ if (!p || heap [p]->at <= w->at)
break;
heap [k] = heap [p];
- ((W)heap [k])->active = k + 1;
+ ((W)heap [k])->active = k;
k = p;
}
heap [k] = w;
- ((W)heap [k])->active = k + 1;
+ ((W)heap [k])->active = k;
}
/* away from the root */
@@ -786,25 +789,25 @@ downheap (WT *heap, int N, int k)
for (;;)
{
- int c = (k << 1) + 1;
+ int c = k << 1;
- if (c >= N)
+ if (c > N)
break;
- c += c + 1 < N && heap [c]->at > heap [c + 1]->at
+ c += c < N && heap [c]->at > heap [c + 1]->at
? 1 : 0;
if (w->at <= heap [c]->at)
break;
heap [k] = heap [c];
- ((W)heap [k])->active = k + 1;
+ ((W)heap [k])->active = k;
k = c;
}
heap [k] = w;
- ((W)heap [k])->active = k + 1;
+ ((W)heap [k])->active = k;
}
void inline_size
@@ -1460,9 +1463,9 @@ call_pending (EV_P)
void inline_size
timers_reify (EV_P)
{
- while (timercnt && ((WT)timers [0])->at <= mn_now)
+ while (timercnt && ev_at (timers [1]) <= mn_now)
{
- ev_timer *w = (ev_timer *)timers [0];
+ ev_timer *w = (ev_timer *)timers [1];
/*assert (("inactive timer on timer heap detected", ev_is_active (w)));*/
@@ -1471,11 +1474,11 @@ timers_reify (EV_P)
{
assert (("negative ev_timer repeat value found while processing timers", w->repeat > 0.));
- ((WT)w)->at += w->repeat;
- if (((WT)w)->at < mn_now)
- ((WT)w)->at = mn_now;
+ ev_at (w) += w->repeat;
+ if (ev_at (w) < mn_now)
+ ev_at (w) = mn_now;
- downheap (timers, timercnt, 0);
+ downheap (timers, timercnt, 1);
}
else
ev_timer_stop (EV_A_ w); /* nonrepeating: stop timer */
@@ -1488,25 +1491,25 @@ timers_reify (EV_P)
void inline_size
periodics_reify (EV_P)
{
- while (periodiccnt && ((WT)periodics [0])->at <= ev_rt_now)
+ while (periodiccnt && ev_at (periodics [1]) <= ev_rt_now)
{
- ev_periodic *w = (ev_periodic *)periodics [0];
+ ev_periodic *w = (ev_periodic *)periodics [1];
/*assert (("inactive timer on periodic heap detected", ev_is_active (w)));*/
/* first reschedule or stop timer */
if (w->reschedule_cb)
{
- ((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 (periodics, periodiccnt, 0);
+ ev_at (w) = w->reschedule_cb (w, ev_rt_now + TIME_EPSILON);
+ assert (("ev_periodic reschedule callback returned time in the past", ev_at (w) > ev_rt_now));
+ downheap (periodics, periodiccnt, 1);
}
else if (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 (periodics, periodiccnt, 0);
+ ev_at (w) = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
+ if (ev_at (w) - ev_rt_now <= TIME_EPSILON) ev_at (w) += w->interval;
+ assert (("ev_periodic timeout in the past detected while processing timers, negative interval?", ev_at (w) > ev_rt_now));
+ downheap (periodics, periodiccnt, 1);
}
else
ev_periodic_stop (EV_A_ w); /* nonrepeating: stop timer */
@@ -1526,9 +1529,9 @@ periodics_reschedule (EV_P)
ev_periodic *w = (ev_periodic *)periodics [i];
if (w->reschedule_cb)
- ((WT)w)->at = w->reschedule_cb (w, ev_rt_now);
+ ev_at (w) = w->reschedule_cb (w, ev_rt_now);
else if (w->interval)
- ((WT)w)->at = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
+ ev_at (w) = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
}
/* now rebuild the heap */
@@ -1620,8 +1623,8 @@ time_update (EV_P_ ev_tstamp max_block)
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;
+ for (i = 1; i <= timercnt; ++i)
+ ev_at (timers [i]) += ev_rt_now - mn_now;
}
mn_now = ev_rt_now;
@@ -1701,14 +1704,14 @@ ev_loop (EV_P_ int flags)
if (timercnt)
{
- ev_tstamp to = ((WT)timers [0])->at - mn_now + backend_fudge;
+ ev_tstamp to = ev_at (timers [1]) - mn_now + backend_fudge;
if (waittime > to) waittime = to;
}
#if EV_PERIODIC_ENABLE
if (periodiccnt)
{
- ev_tstamp to = ((WT)periodics [0])->at - ev_rt_now + backend_fudge;
+ ev_tstamp to = ev_at (periodics [1]) - ev_rt_now + backend_fudge;
if (waittime > to) waittime = to;
}
#endif
@@ -1884,16 +1887,16 @@ ev_timer_start (EV_P_ ev_timer *w)
if (expect_false (ev_is_active (w)))
return;
- ((WT)w)->at += mn_now;
+ ev_at (w) += mn_now;
assert (("ev_timer_start called with negative timer repeat value", w->repeat >= 0.));
ev_start (EV_A_ (W)w, ++timercnt);
- array_needsize (WT, timers, timermax, timercnt, EMPTY2);
- timers [timercnt - 1] = (WT)w;
- upheap (timers, timercnt - 1);
+ array_needsize (WT, timers, timermax, timercnt + 1, EMPTY2);
+ timers [timercnt] = (WT)w;
+ upheap (timers, timercnt);
- /*assert (("internal timer heap corruption", timers [((W)w)->active - 1] == w));*/
+ /*assert (("internal timer heap corruption", timers [((W)w)->active] == w));*/
}
void noinline
@@ -1903,19 +1906,21 @@ ev_timer_stop (EV_P_ ev_timer *w)
if (expect_false (!ev_is_active (w)))
return;
- assert (("internal timer heap corruption", timers [((W)w)->active - 1] == (WT)w));
+ assert (("internal timer heap corruption", timers [((W)w)->active] == (WT)w));
{
int active = ((W)w)->active;
- if (expect_true (--active < --timercnt))
+ if (expect_true (active < timercnt))
{
timers [active] = timers [timercnt];
adjustheap (timers, timercnt, active);
}
+
+ --timercnt;
}
- ((WT)w)->at -= mn_now;
+ ev_at (w) -= mn_now;
ev_stop (EV_A_ (W)w);
}
@@ -1927,8 +1932,8 @@ ev_timer_again (EV_P_ ev_timer *w)
{
if (w->repeat)
{
- ((WT)w)->at = mn_now + w->repeat;
- adjustheap (timers, timercnt, ((W)w)->active - 1);
+ ev_at (w) = mn_now + w->repeat;
+ adjustheap (timers, timercnt, ((W)w)->active);
}
else
ev_timer_stop (EV_A_ w);
@@ -1948,20 +1953,20 @@ ev_periodic_start (EV_P_ ev_periodic *w)
return;
if (w->reschedule_cb)
- ((WT)w)->at = w->reschedule_cb (w, ev_rt_now);
+ ev_at (w) = w->reschedule_cb (w, ev_rt_now);
else if (w->interval)
{
assert (("ev_periodic_start called with negative interval value", w->interval >= 0.));
/* this formula differs from the one in periodic_reify because we do not always round up */
- ((WT)w)->at = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
+ ev_at (w) = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
}
else
- ((WT)w)->at = w->offset;
+ ev_at (w) = w->offset;
ev_start (EV_A_ (W)w, ++periodiccnt);
- array_needsize (WT, periodics, periodicmax, periodiccnt, EMPTY2);
- periodics [periodiccnt - 1] = (WT)w;
- upheap (periodics, periodiccnt - 1);
+ array_needsize (WT, periodics, periodicmax, periodiccnt + 1, EMPTY2);
+ periodics [periodiccnt] = (WT)w;
+ upheap (periodics, periodiccnt);
/*assert (("internal periodic heap corruption", periodics [((W)w)->active - 1] == w));*/
}
@@ -1973,16 +1978,18 @@ ev_periodic_stop (EV_P_ ev_periodic *w)
if (expect_false (!ev_is_active (w)))
return;
- assert (("internal periodic heap corruption", periodics [((W)w)->active - 1] == (WT)w));
+ assert (("internal periodic heap corruption", periodics [((W)w)->active] == (WT)w));
{
int active = ((W)w)->active;
- if (expect_true (--active < --periodiccnt))
+ if (expect_true (active < periodiccnt))
{
periodics [active] = periodics [periodiccnt];
adjustheap (periodics, periodiccnt, active);
}
+
+ --periodiccnt;
}
ev_stop (EV_A_ (W)w);