make timers best-effort non-drifting

[software/libev.git] / ev.c

diff --git a/ev.c b/ev.c
index 14046a2b3b1206a3460f824d14fd7c67880e5373..a605a57ba6c520032cf7d0810936dc3d3ae44ef3 100644 (file)
--- a/ev.c
+++ b/ev.c
@@ -28,6 +28,11 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #ifndef EV_STANDALONE
 # include "config.h"
 
@@ -48,7 +53,7 @@
 #  define EV_USE_EPOLL 1
 # endif
 
-# if HAVE_KQUEUE && HAVE_WORKING_KQUEUE && HAVE_SYS_EVENT_H && HAVE_SYS_QUEUE_H
+# if HAVE_KQUEUE && HAVE_SYS_EVENT_H && HAVE_SYS_QUEUE_H
 #  define EV_USE_KQUEUE 1
 # endif
 
@@ -223,6 +228,7 @@ typedef struct
 
   struct ev_loop
   {
+    ev_tstamp ev_rt_now;
     #define VAR(name,decl) decl;
       #include "ev_vars.h"
     #undef VAR
@@ -234,6 +240,7 @@ typedef struct
 
 #else
 
+  ev_tstamp ev_rt_now;
   #define VAR(name,decl) static decl;
     #include "ev_vars.h"
   #undef VAR
@@ -273,11 +280,13 @@ get_clock (void)
   return ev_time ();
 }
 
+#if EV_MULTIPLICITY
 ev_tstamp
 ev_now (EV_P)
 {
-  return rt_now;
+  return ev_rt_now;
 }
+#endif
 
 #define array_roundsize(type,n) ((n) | 4 & ~3)
 
@@ -737,10 +746,10 @@ loop_init (EV_P_ int methods)
       }
 #endif
 
-      rt_now    = ev_time ();
+      ev_rt_now = ev_time ();
       mn_now    = get_clock ();
       now_floor = mn_now;
-      rtmn_diff = rt_now - mn_now;
+      rtmn_diff = ev_rt_now - mn_now;
 
       if (methods == EVMETHOD_AUTO)
         if (!enable_secure () && getenv ("LIBEV_METHODS"))
@@ -980,7 +989,11 @@ timers_reify (EV_P)
       if (w->repeat)
         {
           assert (("negative ev_timer repeat value found while processing timers", w->repeat > 0.));
-          ((WT)w)->at = mn_now + w->repeat;
+
+          ((WT)w)->at += w->repeat;
+          if (((WT)w)->at < mn_now)
+            ((WT)w)->at = mn_now;
+
           downheap ((WT *)timers, timercnt, 0);
         }
       else
@@ -993,7 +1006,7 @@ timers_reify (EV_P)
 static void
 periodics_reify (EV_P)
 {
-  while (periodiccnt && ((WT)periodics [0])->at <= rt_now)
+  while (periodiccnt && ((WT)periodics [0])->at <= ev_rt_now)
     {
       struct ev_periodic *w = periodics [0];
 
@@ -1002,15 +1015,15 @@ periodics_reify (EV_P)
       /* first reschedule or stop timer */
       if (w->reschedule_cb)
         {
-          ev_tstamp at = ((WT)w)->at = w->reschedule_cb (w, rt_now + 0.0001);
+          ev_tstamp at = ((WT)w)->at = w->reschedule_cb (w, ev_rt_now + 0.0001);
 
-          assert (("ev_periodic reschedule callback returned time in the past", ((WT)w)->at > rt_now));
+          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 ((rt_now - ((WT)w)->at) / w->interval + 1.) * w->interval;
-          assert (("ev_periodic timeout in the past detected while processing timers, negative interval?", ((WT)w)->at > rt_now));
+          ((WT)w)->at += floor ((ev_rt_now - ((WT)w)->at) / w->interval + 1.) * 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);
         }
       else
@@ -1031,9 +1044,9 @@ periodics_reschedule (EV_P)
       struct ev_periodic *w = periodics [i];
 
       if (w->reschedule_cb)
-        ((WT)w)->at = w->reschedule_cb (w, rt_now);
+        ((WT)w)->at = w->reschedule_cb (w, ev_rt_now);
       else if (w->interval)
-        ((WT)w)->at += ceil ((rt_now - ((WT)w)->at) / w->interval) * w->interval;
+        ((WT)w)->at += ceil ((ev_rt_now - ((WT)w)->at) / w->interval) * w->interval;
     }
 
   /* now rebuild the heap */
@@ -1048,13 +1061,13 @@ time_update_monotonic (EV_P)
 
   if (expect_true (mn_now - now_floor < MIN_TIMEJUMP * .5))
     {
-      rt_now = rtmn_diff + mn_now;
+      ev_rt_now = rtmn_diff + mn_now;
       return 0;
     }
   else
     {
       now_floor = mn_now;
-      rt_now = ev_time ();
+      ev_rt_now = ev_time ();
       return 1;
     }
 }
@@ -1073,12 +1086,12 @@ time_update (EV_P)
 
           for (i = 4; --i; ) /* loop a few times, before making important decisions */
             {
-              rtmn_diff = rt_now - mn_now;
+              rtmn_diff = ev_rt_now - mn_now;
 
               if (fabs (odiff - rtmn_diff) < MIN_TIMEJUMP)
                 return; /* all is well */
 
-              rt_now    = ev_time ();
+              ev_rt_now = ev_time ();
               mn_now    = get_clock ();
               now_floor = mn_now;
             }
@@ -1091,18 +1104,18 @@ time_update (EV_P)
   else
 #endif
     {
-      rt_now = ev_time ();
+      ev_rt_now = ev_time ();
 
-      if (expect_false (mn_now > rt_now || mn_now < rt_now - MAX_BLOCKTIME - MIN_TIMEJUMP))
+      if (expect_false (mn_now > ev_rt_now || mn_now < ev_rt_now - MAX_BLOCKTIME - MIN_TIMEJUMP))
         {
           periodics_reschedule (EV_A);
 
           /* adjust timers. this is easy, as the offset is the same for all */
           for (i = 0; i < timercnt; ++i)
-            ((WT)timers [i])->at += rt_now - mn_now;
+            ((WT)timers [i])->at += ev_rt_now - mn_now;
         }
 
-      mn_now = rt_now;
+      mn_now = ev_rt_now;
     }
 }
 
@@ -1152,8 +1165,8 @@ ev_loop (EV_P_ int flags)
       else
 #endif
         {
-          rt_now = ev_time ();
-          mn_now = rt_now;
+          ev_rt_now = ev_time ();
+          mn_now    = ev_rt_now;
         }
 
       if (flags & EVLOOP_NONBLOCK || idlecnt)
@@ -1170,7 +1183,7 @@ ev_loop (EV_P_ int flags)
 
           if (periodiccnt)
             {
-              ev_tstamp to = ((WT)periodics [0])->at - rt_now + method_fudge;
+              ev_tstamp to = ((WT)periodics [0])->at - ev_rt_now + method_fudge;
               if (block > to) block = to;
             }
 
@@ -1179,7 +1192,7 @@ ev_loop (EV_P_ int flags)
 
       method_poll (EV_A_ block);
 
-      /* update rt_now, do magic */
+      /* update ev_rt_now, do magic */
       time_update (EV_A);
 
       /* queue pending timers and reschedule them */
@@ -1285,6 +1298,8 @@ ev_io_stop (EV_P_ struct ev_io *w)
   if (!ev_is_active (w))
     return;
 
+  assert (("ev_io_start called with illegal fd (must stay constant after start!)", w->fd >= 0 && w->fd < anfdmax));
+
   wlist_del ((WL *)&anfds[w->fd].head, (WL)w);
   ev_stop (EV_A_ (W)w);
 
@@ -1350,12 +1365,12 @@ ev_periodic_start (EV_P_ struct ev_periodic *w)
     return;
 
   if (w->reschedule_cb)
-    ((WT)w)->at = w->reschedule_cb (w, rt_now);
+    ((WT)w)->at = 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 += ceil ((rt_now - ((WT)w)->at) / w->interval) * w->interval;
+      ((WT)w)->at += ceil ((ev_rt_now - ((WT)w)->at) / w->interval) * w->interval;
     }
 
   ev_start (EV_A_ (W)w, ++periodiccnt);
@@ -1592,3 +1607,7 @@ ev_once (EV_P_ int fd, int events, ev_tstamp timeout, void (*cb)(int revents, vo
     }
 }
 
+#ifdef __cplusplus
+}
+#endif
+