From: Willy Tarreau <w@1wt.eu>
Date: Mon, 7 Jan 2013 15:19:18 +0000 (+0100)
Subject: OPTIM: epoll: make use of EPOLLRDHUP
X-Git-Tag: v1.5-dev18~130
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1c07b0755df77d5e9c867694c73c9338150a746a;p=thirdparty%2Fhaproxy.git

OPTIM: epoll: make use of EPOLLRDHUP

epoll may report pending shutdowns using EPOLLRDHUP. Since this
flag is missing from a number of libcs despite being available
since kernel 2.6.17, let's define it ourselves.

Doing so saves one syscall by allow us to avoid the read()==0 when
the server closes with the respose.
---

diff --git a/src/ev_epoll.c b/src/ev_epoll.c
index 90efaee054..034ec4c7d2 100644
--- a/src/ev_epoll.c
+++ b/src/ev_epoll.c
@@ -40,6 +40,11 @@ static int epoll_fd;
  */
 static struct epoll_event ev;
 
+#ifndef EPOLLRDHUP
+/* EPOLLRDHUP was defined late in libc, and it appeared in kernel 2.6.17 */
+#define EPOLLRDHUP 0x2000
+#endif
+
 /*
  * speculative epoll() poller
  */
@@ -76,7 +81,7 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 				/* construct the epoll events based on new state */
 				ev.events = 0;
 				if (en & FD_EV_POLLED_R)
-					ev.events |= EPOLLIN;
+					ev.events |= EPOLLIN | EPOLLRDHUP;
 
 				if (en & FD_EV_POLLED_W)
 					ev.events |= EPOLLOUT;
@@ -137,8 +142,8 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 	/* process polled events */
 
 	for (count = 0; count < status; count++) {
-		unsigned char n;
-		unsigned char e = epoll_events[count].events;
+		unsigned int n;
+		unsigned int e = epoll_events[count].events;
 		fd = epoll_events[count].data.fd;
 
 		if (!fdtab[fd].owner)
@@ -161,6 +166,10 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 				((e & EPOLLHUP) ? FD_POLL_HUP : 0);
 		}
 
+		/* always remap RDHUP to HUP as they're used similarly */
+		if (e & EPOLLRDHUP)
+			n |= FD_POLL_HUP;
+
 		if (!n)
 			continue;