X-Git-Url: https://git.llucax.com/software/libev.git/blobdiff_plain/480621758fe1687120978562a553920ed46e1b7e..4ce77a5b1de05dae6092eae478b2a4397173d9c3:/ev.c

diff --git a/ev.c b/ev.c
index 7e9423e..acde504 100644
--- a/ev.c
+++ b/ev.c
@@ -218,29 +218,40 @@ extern "C" {
 
 /**/
 
+/*
+ * 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))
-# define inline_size                static inline /* inline for codesize */
-# if EV_MINIMAL
-#  define noinline                  __attribute__ ((noinline))
-#  define inline_speed              static noinline
-# else
-#  define noinline
-#  define inline_speed              static inline
-# endif
+# define noinline                   __attribute__ ((noinline))
 #else
 # define expect(expr,value)         (expr)
-# define inline_speed               static
-# define inline_size                static
 # define noinline
+# if __STDC_VERSION__ < 199901L
+#  define inline
+# endif
 #endif
 
 #define expect_false(expr) expect ((expr) != 0, 0)
 #define expect_true(expr)  expect ((expr) != 0, 1)
+#define inline_size        static inline
+
+#if EV_MINIMAL
+# define inline_speed      static noinline
+#else
+# define inline_speed      static inline
+#endif
 
 #define NUMPRI    (EV_MAXPRI - EV_MINPRI + 1)
 #define ABSPRI(w) (((W)w)->priority - EV_MINPRI)
@@ -419,7 +430,7 @@ array_nextsize (int elem, int cur, int cnt)
   return ncur;
 }
 
-inline_speed void *
+static noinline void *
 array_realloc (int elem, void *base, int *cur, int cnt)
 {
   *cur = array_nextsize (elem, *cur, cnt);
@@ -454,17 +465,17 @@ void noinline
 ev_feed_event (EV_P_ void *w, int revents)
 {
   W w_ = (W)w;
+  int pri = ABSPRI (w_);
 
   if (expect_false (w_->pending))
+    pendings [pri][w_->pending - 1].events |= revents;
+  else
     {
-      pendings [ABSPRI (w_)][w_->pending - 1].events |= revents;
-      return;
+      w_->pending = ++pendingcnt [pri];
+      array_needsize (ANPENDING, pendings [pri], pendingmax [pri], w_->pending, EMPTY2);
+      pendings [pri][w_->pending - 1].w      = w_;
+      pendings [pri][w_->pending - 1].events = revents;
     }
-
-  w_->pending = ++pendingcnt [ABSPRI (w_)];
-  array_needsize (ANPENDING, pendings [ABSPRI (w_)], pendingmax [ABSPRI (w_)], pendingcnt [ABSPRI (w_)], EMPTY2);
-  pendings [ABSPRI (w_)][w_->pending - 1].w      = w_;
-  pendings [ABSPRI (w_)][w_->pending - 1].events = revents;
 }
 
 void inline_size
@@ -750,7 +761,7 @@ sigcb (EV_P_ ev_io *iow, int revents)
       ev_feed_signal_event (EV_A_ signum + 1);
 }
 
-void inline_size
+void inline_speed
 fd_intern (int fd)
 {
 #ifdef _WIN32
@@ -1232,13 +1243,14 @@ periodics_reify (EV_P)
       /* 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 += floor ((ev_rt_now - ((WT)w)->at) / 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);
         }
@@ -1262,7 +1274,7 @@ periodics_reschedule (EV_P)
       if (w->reschedule_cb)
         ((WT)w)->at = w->reschedule_cb (w, ev_rt_now);
       else if (w->interval)
-        ((WT)w)->at += ceil ((ev_rt_now - ((WT)w)->at) / w->interval) * w->interval;
+        ((WT)w)->at = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
     }
 
   /* now rebuild the heap */
@@ -1294,74 +1306,65 @@ idle_reify (EV_P)
 }
 #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;
+        }
 
-              if (fabs (odiff - rtmn_diff) < MIN_TIMEJUMP)
-                return; /* all is well */
+      now_floor = mn_now;
+      ev_rt_now = ev_time ();
 
-              ev_rt_now = ev_time ();
-              mn_now    = get_clock ();
-              now_floor = mn_now;
-            }
+      /* 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;
+
+          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;
@@ -1415,7 +1418,7 @@ ev_loop (EV_P_ int flags)
           }
 #endif
 
-      /* queue check watchers (and execute them) */
+      /* queue prepare watchers (and execute them) */
       if (expect_false (preparecnt))
         {
           queue_events (EV_A_ (W *)prepares, preparecnt, EV_PREPARE);
@@ -1441,15 +1444,7 @@ ev_loop (EV_P_ int flags)
         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;
 
@@ -1472,10 +1467,10 @@ ev_loop (EV_P_ int flags)
 
         ++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 */
@@ -1547,14 +1542,15 @@ ev_clear_pending (EV_P_ void *w)
   W w_ = (W)w;
   int pending = w_->pending;
 
-  if (!pending)
+  if (expect_true (pending))
+    {
+      ANPENDING *p = pendings [ABSPRI (w_)] + pending - 1;
+      w_->pending = 0;
+      p->w = 0;
+      return p->events;
+    }
+  else
     return 0;
-
-  w_->pending = 0;
-  ANPENDING *p = pendings [ABSPRI (w_)] + pending - 1;
-  p->w = 0;
-
-  return p->events;
 }
 
 void inline_size
@@ -1583,7 +1579,7 @@ ev_stop (EV_P_ W w)
 
 /*****************************************************************************/
 
-void
+void noinline
 ev_io_start (EV_P_ ev_io *w)
 {
   int fd = w->fd;
@@ -1600,7 +1596,7 @@ ev_io_start (EV_P_ ev_io *w)
   fd_change (EV_A_ fd);
 }
 
-void
+void noinline
 ev_io_stop (EV_P_ ev_io *w)
 {
   clear_pending (EV_A_ (W)w);
@@ -1615,7 +1611,7 @@ ev_io_stop (EV_P_ ev_io *w)
   fd_change (EV_A_ w->fd);
 }
 
-void
+void noinline
 ev_timer_start (EV_P_ ev_timer *w)
 {
   if (expect_false (ev_is_active (w)))
@@ -1633,7 +1629,7 @@ ev_timer_start (EV_P_ ev_timer *w)
   /*assert (("internal timer heap corruption", timers [((W)w)->active - 1] == w));*/
 }
 
-void
+void noinline
 ev_timer_stop (EV_P_ ev_timer *w)
 {
   clear_pending (EV_A_ (W)w);
@@ -1657,7 +1653,7 @@ ev_timer_stop (EV_P_ ev_timer *w)
   ev_stop (EV_A_ (W)w);
 }
 
-void
+void noinline
 ev_timer_again (EV_P_ ev_timer *w)
 {
   if (ev_is_active (w))
@@ -1678,7 +1674,7 @@ ev_timer_again (EV_P_ ev_timer *w)
 }
 
 #if EV_PERIODIC_ENABLE
-void
+void noinline
 ev_periodic_start (EV_P_ ev_periodic *w)
 {
   if (expect_false (ev_is_active (w)))
@@ -1690,8 +1686,10 @@ ev_periodic_start (EV_P_ ev_periodic *w)
     {
       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 += ceil ((ev_rt_now - ((WT)w)->at) / w->interval) * w->interval;
+      ((WT)w)->at = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval;
     }
+  else
+    ((WT)w)->at = w->offset;
 
   ev_start (EV_A_ (W)w, ++periodiccnt);
   array_needsize (ev_periodic *, periodics, periodicmax, periodiccnt, EMPTY2);
@@ -1701,7 +1699,7 @@ ev_periodic_start (EV_P_ ev_periodic *w)
   /*assert (("internal periodic heap corruption", periodics [((W)w)->active - 1] == w));*/
 }
 
-void
+void noinline
 ev_periodic_stop (EV_P_ ev_periodic *w)
 {
   clear_pending (EV_A_ (W)w);
@@ -1723,7 +1721,7 @@ ev_periodic_stop (EV_P_ ev_periodic *w)
   ev_stop (EV_A_ (W)w);
 }
 
-void
+void noinline
 ev_periodic_again (EV_P_ ev_periodic *w)
 {
   /* TODO: use adjustheap and recalculation */
@@ -1736,7 +1734,7 @@ ev_periodic_again (EV_P_ ev_periodic *w)
 # define SA_RESTART 0
 #endif
 
-void
+void noinline
 ev_signal_start (EV_P_ ev_signal *w)
 {
 #if EV_MULTIPLICITY
@@ -1765,7 +1763,7 @@ ev_signal_start (EV_P_ ev_signal *w)
     }
 }
 
-void
+void noinline
 ev_signal_stop (EV_P_ ev_signal *w)
 {
   clear_pending (EV_A_ (W)w);