3 files changed, 16 insertions, 0 deletions
diff --git a/conf.c b/conf.c
index 029b9c7..6f86940 100644
--- a/conf.c
+++ b/conf.c
@@ -2084,6 +2084,13 @@ static void conf_accept(struct ctx *c)
 	int fd, rc;
 
 retry:
+	/* Currently we perform the configuration transaction more-or-less
+	 * synchronously, so we want the accepted socket to be blocking.
+	 *
+	 * FIXME: We should make the configuration update asynchronous, like
+	 * most of our operation, so a misbehaving configuration client can't
+	 * block the main forwarding loop.
+	 */
 	fd = accept4(c->fd_control_listen, NULL, NULL, SOCK_CLOEXEC);
 	if (fd < 0) {
 		if (errno != EAGAIN)
diff --git a/repair.c b/repair.c
index 3e0e3e0..f31ccce 100644
--- a/repair.c
+++ b/repair.c
@@ -99,6 +99,10 @@ int repair_listen_handler(struct ctx *c, uint32_t events)
 		return EEXIST;
 	}
 
+	/* We want the accepted socket to be blocking; we use it during
+	 * migration which is a synchronous interruption to our normal
+	 * non-blocking behaviour.
+	 */
 	if ((c->fd_repair = accept4(c->fd_repair_listen, NULL, NULL,
 				    SOCK_CLOEXEC)) < 0) {
 		rc = errno;
diff --git a/tap.c b/tap.c
index b318327..4cba4c7 100644
--- a/tap.c
+++ b/tap.c
@@ -1492,6 +1492,11 @@ void tap_listen_handler(struct ctx *c, uint32_t events)
 		return;
 	}
 
+	/* Because we generally only access the accepted socket from epoll
+	 * events, it usually doesn't matter if it's blocking or non-blocking.
+	 * However, in rare cases when the socket buffer fills we need (briefly,
+	 * we hope) blocking writes (write_remainder() in send_frames_passt()).
+	 */
 	c->fd_tap = accept4(c->fd_tap_listen, NULL, NULL, SOCK_CLOEXEC);
 	if (c->fd_tap < 0) {
 		warn_perror("Error accepting tap client");