From d79e79b436144654d10124de7d5fd4c896ac0487 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Sun, 10 May 2009 10:18:54 +0200
Subject: [PATCH] [BUG] O(1) pollers should check their FD before closing it

epoll, sepoll and kqueue pollers should check that their fd is not
closed before attempting to close it, otherwise we can end up with
multiple closes of fd #0 upon exit, which is harmless but dirty.
---
 src/ev_epoll.c  | 13 +++++++++----
 src/ev_kqueue.c | 14 ++++++++++----
 src/ev_sepoll.c | 13 +++++++++----
 3 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/ev_epoll.c b/src/ev_epoll.c
index 345b0b2ac..b976868ea 100644
--- a/src/ev_epoll.c
+++ b/src/ev_epoll.c
@@ -312,7 +312,7 @@ REGPRM1 static int _do_init(struct poller *p)
 	free(epoll_events);
  fail_ee:
 	close(epoll_fd);
-	epoll_fd = 0;
+	epoll_fd = -1;
  fail_fd:
 	p->pref = 0;
 	return 0;
@@ -331,8 +331,10 @@ REGPRM1 static void _do_term(struct poller *p)
 	free(fd_evts);
 	free(epoll_events);
 
-	close(epoll_fd);
-	epoll_fd = 0;
+	if (epoll_fd >= 0) {
+		close(epoll_fd);
+		epoll_fd = -1;
+	}
 
 	chg_ptr = NULL;
 	chg_list = NULL;
@@ -366,7 +368,8 @@ REGPRM1 static int _do_test(struct poller *p)
  */
 REGPRM1 static int _do_fork(struct poller *p)
 {
-	close(epoll_fd);
+	if (epoll_fd >= 0)
+		close(epoll_fd);
 	epoll_fd = epoll_create(global.maxsock + 1);
 	if (epoll_fd < 0)
 		return 0;
@@ -385,6 +388,8 @@ static void _do_register(void)
 
 	if (nbpollers >= MAX_POLLERS)
 		return;
+
+	epoll_fd = -1;
 	p = &pollers[nbpollers++];
 
 	p->name = "epoll";
diff --git a/src/ev_kqueue.c b/src/ev_kqueue.c
index 7e626d112..e16798424 100644
--- a/src/ev_kqueue.c
+++ b/src/ev_kqueue.c
@@ -188,7 +188,7 @@ REGPRM1 static int _do_init(struct poller *p)
 	free(kev);
  fail_kev:
 	close(kqueue_fd);
-	kqueue_fd = 0;
+	kqueue_fd = -1;
  fail_fd:
 	p->pref = 0;
 	return 0;
@@ -203,8 +203,11 @@ REGPRM1 static void _do_term(struct poller *p)
 	free(fd_evts[DIR_WR]);
 	free(fd_evts[DIR_RD]);
 	free(kev);
-	close(kqueue_fd);
-	kqueue_fd = 0;
+
+	if (kqueue_fd >= 0) {
+		close(kqueue_fd);
+		kqueue_fd = -1;
+	}
 
 	p->private = NULL;
 	p->pref = 0;
@@ -232,7 +235,8 @@ REGPRM1 static int _do_test(struct poller *p)
  */
 REGPRM1 static int _do_fork(struct poller *p)
 {
-	close(kqueue_fd);
+	if (kqueue_fd >= 0)
+		close(kqueue_fd);
 	kqueue_fd = kqueue();
 	if (kqueue_fd < 0)
 		return 0;
@@ -251,6 +255,8 @@ static void _do_register(void)
 
 	if (nbpollers >= MAX_POLLERS)
 		return;
+
+	kqueue_fd = -1;
 	p = &pollers[nbpollers++];
 
 	p->name = "kqueue";
diff --git a/src/ev_sepoll.c b/src/ev_sepoll.c
index a093693f3..13e890b62 100644
--- a/src/ev_sepoll.c
+++ b/src/ev_sepoll.c
@@ -591,7 +591,7 @@ REGPRM1 static int _do_init(struct poller *p)
 	free(epoll_events);
  fail_ee:
 	close(epoll_fd);
-	epoll_fd = 0;
+	epoll_fd = -1;
  fail_fd:
 	p->pref = 0;
 	return 0;
@@ -607,8 +607,10 @@ REGPRM1 static void _do_term(struct poller *p)
 	free(spec_list);
 	free(epoll_events);
 
-	close(epoll_fd);
-	epoll_fd = 0;
+	if (epoll_fd >= 0) {
+		close(epoll_fd);
+		epoll_fd = -1;
+	}
 
 	fd_list = NULL;
 	spec_list = NULL;
@@ -641,7 +643,8 @@ REGPRM1 static int _do_test(struct poller *p)
  */
 REGPRM1 static int _do_fork(struct poller *p)
 {
-	close(epoll_fd);
+	if (epoll_fd >= 0)
+		close(epoll_fd);
 	epoll_fd = epoll_create(global.maxsock + 1);
 	if (epoll_fd < 0)
 		return 0;
@@ -660,6 +663,8 @@ static void _do_register(void)
 
 	if (nbpollers >= MAX_POLLERS)
 		return;
+
+	epoll_fd = -1;
 	p = &pollers[nbpollers++];
 
 	p->name = "sepoll";