- add non-os-assisted ev_stat watcher

[software/libev.git] / ev_epoll.c

diff --git a/ev_epoll.c b/ev_epoll.c
index 11ee92607b30267339dac5fa48a32f2c294adfc3..4edbecd1bdaf75541ded85208de8b5e0b1157fc2 100644 (file)
--- a/ev_epoll.c
+++ b/ev_epoll.c
@@ -1,77 +1,122 @@
-#include <sys/epoll.h>
+/*
+ * libev epoll fd activity backend
+ *
+ * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *
+ *     * Redistributions in binary form must reproduce the above
+ *       copyright notice, this list of conditions and the following
+ *       disclaimer in the documentation and/or other materials provided
+ *       with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
 
-static int epoll_fd = -1;
+#include <sys/epoll.h>
 
 static void
-epoll_modify (int fd, int oev, int nev)
+epoll_modify (EV_P_ int fd, int oev, int nev)
 {
   int mode = nev ? oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD : EPOLL_CTL_DEL;
 
   struct epoll_event ev;
-  ev.data.fd = fd;
+  ev.data.u64 = fd; /* use u64 to fully initialise the struct, for nicer strace etc. */
   ev.events =
       (nev & EV_READ ? EPOLLIN : 0)
       | (nev & EV_WRITE ? EPOLLOUT : 0);
 
-  fprintf (stderr, "reify %d,%d,%d m%d (r=%d)\n", fd, oev, nev, mode,//D
-  epoll_ctl (epoll_fd, mode, fd, &ev)
-  );//D
-}
-
-void epoll_postfork_child (void)
-{
-  int fd;
-
-  epoll_fd = epoll_create (256);
-  fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
-
-  /* re-register interest in fds */
-  for (fd = 0; fd < anfdmax; ++fd)
-    if (anfds [fd].wev)
-      epoll_modify (fd, EV_NONE, anfds [fd].wev);
+  if (epoll_ctl (backend_fd, mode, fd, &ev))
+    if (errno != ENOENT /* on ENOENT the fd went away, so try to do the right thing */
+        || (nev && epoll_ctl (backend_fd, EPOLL_CTL_ADD, fd, &ev)))
+      fd_kill (EV_A_ fd);
 }
 
-static struct epoll_event *events;
-static int eventmax;
-
-static void epoll_poll (ev_tstamp timeout)
+static void
+epoll_poll (EV_P_ ev_tstamp timeout)
 {
-  int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.));
   int i;
+  int eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, (int)ceil (timeout * 1000.));
 
   if (eventcnt < 0)
-    return;
+    {
+      if (errno != EINTR)
+        syserr ("(libev) epoll_wait");
+
+      return;
+    }
 
   for (i = 0; i < eventcnt; ++i)
     fd_event (
-      events [i].data.fd,
-      (events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
-      | (events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)
+      EV_A_
+      epoll_events [i].data.u64,
+      (epoll_events [i].events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
+      | (epoll_events [i].events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0)
     );
 
   /* if the receive array was full, increase its size */
-  if (eventcnt == eventmax)
+  if (expect_false (eventcnt == epoll_eventmax))
     {
-      free (events);
-      eventmax += eventmax >> 1;
-      events = malloc (sizeof (struct epoll_event) * eventmax);
+      ev_free (epoll_events);
+      epoll_eventmax = array_roundsize (epoll_events, epoll_eventmax << 1);
+      epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax);
     }
 }
 
-void epoll_init (int flags)
+static int
+epoll_init (EV_P_ int flags)
+{
+  backend_fd = epoll_create (256);
+
+  if (backend_fd < 0)
+    return 0;
+
+  fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
+
+  backend_fudge  = 1e-3; /* needed to compensate for epoll returning early */
+  backend_modify = epoll_modify;
+  backend_poll   = epoll_poll;
+
+  epoll_eventmax = 64; /* intiial number of events receivable per poll */
+  epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax);
+
+  return EVBACKEND_EPOLL;
+}
+
+static void
+epoll_destroy (EV_P)
 {
-  epoll_fd = epoll_create (256);
+  close (backend_fd);
+
+  ev_free (epoll_events);
+}
 
-  if (epoll_fd < 0)
-    return;
+static void
+epoll_fork (EV_P)
+{
+  close (backend_fd);
 
-  fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
+  while ((backend_fd = epoll_create (256)) < 0)
+    syserr ("(libev) epoll_create");
 
-  ev_method     = EVMETHOD_EPOLL;
-  method_fudge  = 1e-3; /* needed to compensate for epoll returning early */
-  method_modify = epoll_modify;
-  method_poll   = epoll_poll;
+  fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
 
-  eventmax = 64; /* intiial number of events receivable per poll */
-  events = malloc (sizeof (struct epoll_event) * eventmax);
+  fd_rearm_all (EV_A);
 }
+