README

1 files changed, 110 insertions, 0 deletions

diff --git a/ev_poll.c b/ev_poll.c
new file mode 100644
index 0000000..4793212
--- /dev/null
+++ b/ev_poll.c
@@ -0,0 +1,110 @@
+/*
+ * 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.
+ */
+
+#include <sys/epoll.h>
+
+static int epoll_fd = -1;
+
+static void
+epoll_modify (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.events =
+      (nev & EV_READ ? EPOLLIN : 0)
+      | (nev & EV_WRITE ? EPOLLOUT : 0);
+
+  epoll_ctl (epoll_fd, mode, fd, &ev);
+}
+
+static 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].events)//D
+      epoll_modify (fd, EV_NONE, anfds [fd].events);
+}
+
+static struct epoll_event *events;
+static int eventmax;
+
+static void
+epoll_poll (ev_tstamp timeout)
+{
+  int eventcnt = epoll_wait (epoll_fd, events, eventmax, ceil (timeout * 1000.));
+  int i;
+
+  if (eventcnt < 0)
+    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)
+    );
+
+  /* if the receive array was full, increase its size */
+  if (expect_false (eventcnt == eventmax))
+    {
+      free (events);
+      eventmax = array_roundsize (events, eventmax << 1);
+      events = malloc (sizeof (struct epoll_event) * eventmax);
+    }
+}
+
+static void
+epoll_init (int flags)
+{
+  epoll_fd = epoll_create (256);
+
+  if (epoll_fd < 0)
+    return;
+
+  fcntl (epoll_fd, F_SETFD, FD_CLOEXEC);
+
+  ev_method     = EVMETHOD_EPOLL;
+  method_fudge  = 1e-3; /* needed to compensate for epoll returning early */
+  method_modify = epoll_modify;
+  method_poll   = epoll_poll;
+
+  eventmax = 64; /* intiial number of events receivable per poll */
+  events = malloc (sizeof (struct epoll_event) * eventmax);
+}
+