From bac906c76119ed8c8915e3979160fac7e12eac05 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 10 Feb 2012 16:39:46 -0500
Subject: [PATCH] Prefer epoll_create1 on Linuxen that have it

---
 configure.in |  1 +
 epoll.c      | 23 ++++++++++++++---------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/configure.in b/configure.in
index 021f97c07e..8c7e3e9847 100644
--- a/configure.in
+++ b/configure.in
@@ -310,6 +310,7 @@ AC_CHECK_FUNCS([ \
   arc4random_buf \
   clock_gettime \
   eventfd \
+  epoll_create1 \
   fcntl \
   getegid \
   geteuid \
diff --git a/epoll.c b/epoll.c
index f1219e7dfb..8dc2515d0a 100644
--- a/epoll.c
+++ b/epoll.c
@@ -108,19 +108,24 @@ const struct eventop epollops = {
 static void *
 epoll_init(struct event_base *base)
 {
-	int epfd;
+	int epfd = -1;
 	struct epollop *epollop;
 
-	/* Initialize the kernel queue.  (The size field is ignored since
-	 * 2.6.8.) */
-	if ((epfd = epoll_create(32000)) == -1) {
-		if (errno != ENOSYS)
-			event_warn("epoll_create");
-		return (NULL);
+#ifdef _EVENT_HAVE_EPOLL_CREATE1
+	/* First, try the shiny new epoll_create1 interface, if we have it. */
+	epfd = epoll_create1(EPOLL_CLOEXEC);
+#endif
+	if (epfd == -1) {
+		/* Initialize the kernel queue using the old interface.  (The
+		size field is ignored   since 2.6.8.) */
+		if ((epfd = epoll_create(32000)) == -1) {
+			if (errno != ENOSYS)
+				event_warn("epoll_create");
+			return (NULL);
+		}
+		evutil_make_socket_closeonexec(epfd);
 	}
 
-	evutil_make_socket_closeonexec(epfd);
-
 	if (!(epollop = mm_calloc(1, sizeof(struct epollop)))) {
 		close(epfd);
 		return (NULL);