make timers best-effort non-drifting

[software/libev.git] / ev_kqueue.c

diff --git a/ev_kqueue.c b/ev_kqueue.c
index 4bbcf39ca3ddde43b24cf5b774f72259181de9ca..4933270c1d2d893f8f7acec0a5db4fd97057237d 100644 (file)
--- a/ev_kqueue.c
+++ b/ev_kqueue.c
@@ -34,20 +34,14 @@
 #include <string.h>
 #include <errno.h>
 
 #include <string.h>
 #include <errno.h>
 

-static int kq_fd;
-static struct kevent *kq_changes;
-static int kq_changemax, kq_changecnt;
-static struct kevent *kq_events;
-static int kq_eventmax;
-

 static void
 static void

-kqueue_change (int fd, int filter, int flags, int fflags)
+kqueue_change (EV_P_ int fd, int filter, int flags, int fflags)

 {
   struct kevent *ke;
 
 {
   struct kevent *ke;
 

-  array_needsize (kq_changes, kq_changemax, ++kq_changecnt, );
+  array_needsize (struct kevent, kqueue_changes, kqueue_changemax, ++kqueue_changecnt, );

 
 

-  ke = &kq_changes [kq_changecnt - 1];
+  ke = &kqueue_changes [kqueue_changecnt - 1];

   memset (ke, 0, sizeof (struct kevent));
   ke->ident  = fd;
   ke->filter = filter;
   memset (ke, 0, sizeof (struct kevent));
   ke->ident  = fd;
   ke->filter = filter;


@@ -60,83 +54,113 @@ kqueue_change (int fd, int filter, int flags, int fflags)
 #endif
 
 static void
 #endif
 
 static void

-kqueue_modify (int fd, int oev, int nev)
+kqueue_modify (EV_P_ int fd, int oev, int nev)

 {
 {

-  if ((oev ^ nev) & EV_READ)
-    {
-      if (nev & EV_READ)
-        kqueue_change (fd, EVFILT_READ, EV_ADD, NOTE_EOF);
-      else
-        kqueue_change (fd, EVFILT_READ, EV_DELETE, 0);
-    }
+  /* to detect close/reopen reliably, we have to remove and re-add */
+  /* event requests even when oev == nev */

 
 

-  if ((oev ^ nev) & EV_WRITE)
-    {
-      if (nev & EV_WRITE)
-        kqueue_change (fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);
-      else
-        kqueue_change (fd, EVFILT_WRITE, EV_DELETE, 0);
-    }
+  if (oev & EV_READ)
+    kqueue_change (EV_A_ fd, EVFILT_READ, EV_DELETE, 0);
+
+  if (oev & EV_WRITE)
+    kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_DELETE, 0);
+
+  if (nev & EV_READ)
+    kqueue_change (EV_A_ fd, EVFILT_READ, EV_ADD, NOTE_EOF);
+
+  if (nev & EV_WRITE)
+    kqueue_change (EV_A_ fd, EVFILT_WRITE, EV_ADD, NOTE_EOF);

 }
 
 static void
 }
 
 static void

-kqueue_poll (ev_tstamp timeout)
+kqueue_poll (EV_P_ ev_tstamp timeout)

 {
   int res, i;
   struct timespec ts;
 
 {
   int res, i;
   struct timespec ts;
 

+  /* need to resize so there is enough space for errors */
+  if (kqueue_changecnt > kqueue_eventmax)
+    {
+      ev_free (kqueue_events);
+      kqueue_eventmax = array_roundsize (struct kevent, kqueue_changecnt);
+      kqueue_events = ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
+    }
+

   ts.tv_sec  = (time_t)timeout;
   ts.tv_nsec = (long)(timeout - (ev_tstamp)ts.tv_sec) * 1e9;
   ts.tv_sec  = (time_t)timeout;
   ts.tv_nsec = (long)(timeout - (ev_tstamp)ts.tv_sec) * 1e9;

-  res = kevent (kq_fd, kq_changes, kq_changecnt, kq_events, kq_eventmax, &ts);
-  kq_changecnt = 0;
+  res = kevent (kqueue_fd, kqueue_changes, kqueue_changecnt, kqueue_events, kqueue_eventmax, &ts);
+  kqueue_changecnt = 0;

 
   if (res < 0)
 
   if (res < 0)

-    return;
+    { 
+      if (errno != EINTR)
+        syserr ("(libev) kevent");
+
+      return;
+    } 

 
   for (i = 0; i < res; ++i)
     {
 
   for (i = 0; i < res; ++i)
     {

-      if (kq_events [i].flags & EV_ERROR)
+      int fd = kqueue_events [i].ident;
+
+      if (kqueue_events [i].flags & EV_ERROR)

         {
         {

+         int err = kqueue_events [i].data;
+

           /* 
           /* 

-           * Error messages that can happen, when a delete fails.
+           * errors that may happen

            *   EBADF happens when the file discriptor has been
            *   closed,
            *   EBADF happens when the file discriptor has been
            *   closed,

-           *   ENOENT when the file discriptor was closed and
+           *   ENOENT when the file descriptor was closed and

            *   then reopened.
            *   EINVAL for some reasons not understood; EINVAL
            *   should not be returned ever; but FreeBSD does :-\
            *   then reopened.
            *   EINVAL for some reasons not understood; EINVAL
            *   should not be returned ever; but FreeBSD does :-\

-           * An error is also indicated when a callback deletes
-           * an event we are still processing.  In that case
-           * the data field is set to ENOENT.

            */
            */

-          if (kq_events [i].data == EBADF)
-            fd_kill (kq_events [i].ident);
+
+          /* we are only interested in errors for fds that we are interested in :) */
+          if (anfds [fd].events)
+           {
+              if (err == ENOENT) /* resubmit changes on ENOENT */
+                kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
+              else if (err == EBADF) /* on EBADF, we re-check the fd */
+                {
+                  if (fd_valid (fd))
+                    kqueue_modify (EV_A_ fd, 0, anfds [fd].events);
+                  else
+                    fd_kill (EV_A_ fd);
+                }
+              else /* on all other errors, we error out on the fd */
+                fd_kill (EV_A_ fd);
+           }

         }
       else
         fd_event (
         }
       else
         fd_event (

-          kq_events [i].ident,
-          kq_events [i].filter == EVFILT_READ ? EV_READ
-          : kq_events [i].filter == EVFILT_WRITE ? EV_WRITE
+          EV_A_
+          fd,
+          kqueue_events [i].filter == EVFILT_READ ? EV_READ
+          : kqueue_events [i].filter == EVFILT_WRITE ? EV_WRITE

           : 0
         );
     }
 
           : 0
         );
     }
 

-  if (expect_false (res == kq_eventmax))
+  if (expect_false (res == kqueue_eventmax))

     {
     {

-      free (kq_events);
-      kq_eventmax = array_roundsize (kq_events, kq_eventmax << 1);
-      kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
+      ev_free (kqueue_events);
+      kqueue_eventmax = array_roundsize (struct kevent, kqueue_eventmax << 1);
+      kqueue_events = ev_malloc (sizeof (struct kevent) * kqueue_eventmax);

     }
 }
 
     }
 }
 

-static void
-kqueue_init (int flags)
+static int
+kqueue_init (EV_P_ int flags)

 {
   struct kevent ch, ev;
 
   /* Initalize the kernel queue */
 {
   struct kevent ch, ev;
 
   /* Initalize the kernel queue */

-  if ((kq_fd = kqueue ()) < 0)
-    return;
+  if ((kqueue_fd = kqueue ()) < 0)
+    return 0;
+
+  fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */

 
   /* Check for Mac OS X kqueue bug. */
   ch.ident  = -1;
 
   /* Check for Mac OS X kqueue bug. */
   ch.ident  = -1;


@@ -148,21 +172,49 @@ kqueue_init (int flags)
    * stick an error in ev. If kqueue is broken, then
    * kevent will fail.
    */
    * stick an error in ev. If kqueue is broken, then
    * kevent will fail.
    */

-  if (kevent (kq_fd, &ch, 1, &ev, 1, 0) != 1
+  if (kevent (kqueue_fd, &ch, 1, &ev, 1, 0) != 1

       || ev.ident != -1
       || ev.flags != EV_ERROR)
     {
       /* detected broken kqueue */
       || ev.ident != -1
       || ev.flags != EV_ERROR)
     {
       /* detected broken kqueue */

-      close (kq_fd);
-      return;
+      close (kqueue_fd);
+      return 0;

     }
 
     }
 

-  ev_method     = EVMETHOD_KQUEUE;

   method_fudge  = 1e-3; /* needed to compensate for kevent returning early */
   method_modify = kqueue_modify;
   method_poll   = kqueue_poll;
 
   method_fudge  = 1e-3; /* needed to compensate for kevent returning early */
   method_modify = kqueue_modify;
   method_poll   = kqueue_poll;
 

-  kq_eventmax = 64; /* intiial number of events receivable per poll */
-  kq_events = malloc (sizeof (struct kevent) * kq_eventmax);
+  kqueue_eventmax = 64; /* intiial number of events receivable per poll */
+  kqueue_events = ev_malloc (sizeof (struct kevent) * kqueue_eventmax);
+
+  kqueue_changes   = 0;
+  kqueue_changemax = 0;
+  kqueue_changecnt = 0;
+
+  return EVMETHOD_KQUEUE;
+}
+
+static void
+kqueue_destroy (EV_P)
+{
+  close (kqueue_fd);
+
+  ev_free (kqueue_events);
+  ev_free (kqueue_changes);
+}
+
+static void
+kqueue_fork (EV_P)
+{
+  close (kqueue_fd);
+
+  while ((kqueue_fd = kqueue ()) < 0)
+    syserr ("(libev) kqueue");
+
+  fcntl (kqueue_fd, F_SETFD, FD_CLOEXEC);
+
+  /* re-register interest in fds */
+  fd_rearm_all (EV_A);

 }
 
 }