created new documentation

[software/libev.git] / ev.c

diff --git a/ev.c b/ev.c
index 3a177c587b804fd80050d8cb543f940a9ce02ff1..46c8cea08e9a74c312b67e8152e68e0dd4f5556e 100644 (file)
--- a/ev.c
+++ b/ev.c
@@ -1,4 +1,6 @@
 /*
+ * libev event processing core, watcher management
+ *
  * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
  * All rights reserved.
  *
@@ -47,9 +49,12 @@
 #include <time.h>
 
 #ifndef EV_USE_MONOTONIC
-# ifdef CLOCK_MONOTONIC
-#  define EV_USE_MONOTONIC 1
-# endif
+# define EV_USE_MONOTONIC 1
+#endif
+
+#ifndef CLOCK_MONOTONIC
+# undef EV_USE_MONOTONIC
+# define EV_USE_MONOTONIC 0
 #endif
 
 #ifndef EV_USE_SELECT
@@ -60,13 +65,17 @@
 # define EV_USE_EPOLL 0
 #endif
 
+#ifndef CLOCK_REALTIME
+# define EV_USE_REALTIME 0
+#endif
 #ifndef EV_USE_REALTIME
 # define EV_USE_REALTIME 1 /* posix requirement, but might be slower */
 #endif
 
 #define MIN_TIMEJUMP  1. /* minimum timejump that gets detected (if monotonic clock available) */
-#define MAX_BLOCKTIME 59.731
-#define PID_HASHSIZE  16 /* size of pid hahs table, must be power of two */
+#define MAX_BLOCKTIME 59.731 /* never wait longer than this time (to detetc time jumps) */
+#define PID_HASHSIZE  16 /* size of pid hash table, must be power of two */
+#define CLEANUP_INTERVAL (MAX_BLOCKTIME * 5.) /* how often to try to free memory and re-check fds */
 
 #include "ev.h"
 
@@ -137,7 +146,8 @@ get_clock (void)
 typedef struct
 {
   struct ev_io *head;
-  int events;
+  unsigned char events;
+  unsigned char reify;
 } ANFD;
 
 static ANFD *anfds;
@@ -150,6 +160,8 @@ anfds_init (ANFD *base, int count)
     {
       base->head   = 0;
       base->events = EV_NONE;
+      base->reify  = 0;
+
       ++base;
     }
 }
@@ -166,6 +178,12 @@ static int pendingmax, pendingcnt;
 static void
 event (W w, int events)
 {
+  if (w->pending)
+    {
+      pendings [w->pending - 1].events |= events;
+      return;
+    }
+
   w->pending = ++pendingcnt;
   array_needsize (pendings, pendingmax, pendingcnt, );
   pendings [pendingcnt - 1].w      = w;
@@ -217,7 +235,7 @@ fd_reify (void)
       for (w = anfd->head; w; w = w->next)
         events |= w->events;
 
-      anfd->events &= ~EV_REIFY;
+      anfd->reify = 0;
 
       if (anfd->events != events)
         {
@@ -232,10 +250,10 @@ fd_reify (void)
 static void
 fd_change (int fd)
 {
-  if (anfds [fd].events & EV_REIFY || fdchangecnt < 0)
+  if (anfds [fd].reify || fdchangecnt < 0)
     return;
 
-  anfds [fd].events |= EV_REIFY;
+  anfds [fd].reify = 1;
 
   ++fdchangecnt;
   array_needsize (fdchanges, fdchangemax, fdchangecnt, );
@@ -253,8 +271,8 @@ fd_recheck (void)
       if (fcntl (fd, F_GETFD) == -1 && errno == EBADF)
         while (anfds [fd].head)
           {
-            event ((W)anfds [fd].head, EV_ERROR | EV_READ | EV_WRITE | EV_TIMEOUT);
             ev_io_stop (anfds [fd].head);
+            event ((W)anfds [fd].head, EV_ERROR | EV_READ | EV_WRITE);
           }
 }
 
@@ -312,14 +330,14 @@ downheap (WT *timers, int N, int k)
 typedef struct
 {
   struct ev_signal *head;
-  sig_atomic_t gotsig;
+  sig_atomic_t volatile gotsig;
 } ANSIG;
 
 static ANSIG *signals;
 static int signalmax;
 
 static int sigpipe [2];
-static sig_atomic_t gotsig;
+static sig_atomic_t volatile gotsig;
 static struct ev_io sigev;
 
 static void
@@ -329,6 +347,7 @@ signals_init (ANSIG *base, int count)
     {
       base->head   = 0;
       base->gotsig = 0;
+
       ++base;
     }
 }
@@ -341,7 +360,7 @@ sighandler (int signum)
   if (!gotsig)
     {
       gotsig = 1;
-      write (sigpipe [1], &gotsig, 1);
+      write (sigpipe [1], &signum, 1);
     }
 }
 
@@ -349,17 +368,17 @@ static void
 sigcb (struct ev_io *iow, int revents)
 {
   struct ev_signal *w;
-  int sig;
+  int signum;
 
-  gotsig = 0;
   read (sigpipe [0], &revents, 1);
+  gotsig = 0;
 
-  for (sig = signalmax; sig--; )
-    if (signals [sig].gotsig)
+  for (signum = signalmax; signum--; )
+    if (signals [signum].gotsig)
       {
-        signals [sig].gotsig = 0;
+        signals [signum].gotsig = 0;
 
-        for (w = signals [sig].head; w; w = w->next)
+        for (w = signals [signum].head; w; w = w->next)
           event ((W)w, EV_SIGNAL);
       }
 }
@@ -406,7 +425,7 @@ childcb (struct ev_signal *sw, int revents)
 
   while ((pid = waitpid (-1, &status, WNOHANG | WUNTRACED | WCONTINUED)) != -1)
     for (w = childs [pid & (PID_HASHSIZE - 1)]; w; w = w->next)
-      if (w->pid == pid || w->pid == -1)
+      if (w->pid == pid || !w->pid)
         {
           w->status = status;
           event ((W)w, EV_CHILD);
@@ -477,19 +496,19 @@ int ev_init (int flags)
 /*****************************************************************************/
 
 void
-ev_prefork (void)
+ev_fork_prepare (void)
 {
   /* nop */
 }
 
 void
-ev_postfork_parent (void)
+ev_fork_parent (void)
 {
   /* nop */
 }
 
 void
-ev_postfork_child (void)
+ev_fork_child (void)
 {
 #if EV_USE_EPOLL
   if (ev_method == EVMETHOD_EPOLL)
@@ -530,8 +549,8 @@ timers_reify (void)
       /* first reschedule or stop timer */
       if (w->repeat)
         {
+          assert (("negative ev_timer repeat value found while processing timers", w->repeat > 0.));
           w->at = now + w->repeat;
-          assert (("timer timeout in the past, negative repeat?", w->at > now));
           downheap ((WT *)timers, timercnt, 0);
         }
       else
@@ -552,13 +571,13 @@ periodics_reify (void)
       if (w->interval)
         {
           w->at += floor ((ev_now - w->at) / w->interval + 1.) * w->interval;
-          assert (("periodic timeout in the past, negative interval?", w->at > ev_now));
+          assert (("ev_periodic timeout in the past detected while processing timers, negative interval?", w->at > ev_now));
           downheap ((WT *)periodics, periodiccnt, 0);
         }
       else
         ev_periodic_stop (w); /* nonrepeating: stop timer */
 
-      event ((W)w, EV_TIMEOUT);
+      event ((W)w, EV_PERIODIC);
     }
 }
 
@@ -723,7 +742,7 @@ wlist_del (WL *head, WL elem)
 }
 
 static void
-ev_clear (W w)
+ev_clear_pending (W w)
 {
   if (w->pending)
     {
@@ -749,10 +768,12 @@ ev_stop (W w)
 void
 ev_io_start (struct ev_io *w)
 {
+  int fd = w->fd;
+
   if (ev_is_active (w))
     return;
 
-  int fd = w->fd;
+  assert (("ev_io_start called with negative fd", fd >= 0));
 
   ev_start ((W)w, 1);
   array_needsize (anfds, anfdmax, fd + 1, anfds_init);
@@ -764,7 +785,7 @@ ev_io_start (struct ev_io *w)
 void
 ev_io_stop (struct ev_io *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (!ev_is_active (w))
     return;
 
@@ -782,7 +803,7 @@ ev_timer_start (struct ev_timer *w)
 
   w->at += now;
 
-  assert (("timer repeat value less than zero not allowed", w->repeat >= 0.));
+  assert (("ev_timer_start called with negative timer repeat value", w->repeat >= 0.));
 
   ev_start ((W)w, ++timercnt);
   array_needsize (timers, timermax, timercnt, );
@@ -793,7 +814,7 @@ ev_timer_start (struct ev_timer *w)
 void
 ev_timer_stop (struct ev_timer *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (!ev_is_active (w))
     return;
 
@@ -831,7 +852,7 @@ ev_periodic_start (struct ev_periodic *w)
   if (ev_is_active (w))
     return;
 
-  assert (("periodic interval value less than zero not allowed", w->interval >= 0.));
+  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 */
   if (w->interval)
@@ -846,7 +867,7 @@ ev_periodic_start (struct ev_periodic *w)
 void
 ev_periodic_stop (struct ev_periodic *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (!ev_is_active (w))
     return;
 
@@ -865,6 +886,8 @@ ev_signal_start (struct ev_signal *w)
   if (ev_is_active (w))
     return;
 
+  assert (("ev_signal_start called with illegal signal number", w->signum > 0));
+
   ev_start ((W)w, 1);
   array_needsize (signals, signalmax, w->signum, signals_init);
   wlist_add ((WL *)&signals [w->signum - 1].head, (WL)w);
@@ -882,7 +905,7 @@ ev_signal_start (struct ev_signal *w)
 void
 ev_signal_stop (struct ev_signal *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (!ev_is_active (w))
     return;
 
@@ -907,7 +930,7 @@ ev_idle_start (struct ev_idle *w)
 void
 ev_idle_stop (struct ev_idle *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (ev_is_active (w))
     return;
 
@@ -929,7 +952,7 @@ ev_prepare_start (struct ev_prepare *w)
 void
 ev_prepare_stop (struct ev_prepare *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (ev_is_active (w))
     return;
 
@@ -951,7 +974,7 @@ ev_check_start (struct ev_check *w)
 void
 ev_check_stop (struct ev_check *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (ev_is_active (w))
     return;
 
@@ -972,7 +995,7 @@ ev_child_start (struct ev_child *w)
 void
 ev_child_stop (struct ev_child *w)
 {
-  ev_clear ((W)w);
+  ev_clear_pending ((W)w);
   if (ev_is_active (w))
     return;