bufferevent: introduce bufferevent_replacefd() (like setfd() but also close fd)

1 files changed, 28 insertions, 0 deletions

diff --git a/bufferevent.c b/bufferevent.c
index 27f2a9ba..53d3a995 100644
--- a/bufferevent.c
+++ b/bufferevent.c
@@ -881,6 +881,34 @@ bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
 	return res;
 }
 
+int
+bufferevent_replacefd(struct bufferevent *bev, evutil_socket_t fd)
+{
+	union bufferevent_ctrl_data d;
+	int err = -1;
+	evutil_socket_t old_fd = EVUTIL_INVALID_SOCKET;
+
+	BEV_LOCK(bev);
+	if (bev->be_ops->ctrl) {
+		err = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
+		if (!err) {
+			old_fd = d.fd;
+			if (old_fd != EVUTIL_INVALID_SOCKET) {
+				err = evutil_closesocket(old_fd);
+			}
+		}
+		if (!err) {
+			d.fd = fd;
+			err = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
+		}
+	}
+	if (err)
+		event_debug(("%s: cannot replace fd for %p from "EV_SOCK_FMT" to "EV_SOCK_FMT, __func__, bev, old_fd, fd));
+	BEV_UNLOCK(bev);
+
+	return err;
+}
+
 evutil_socket_t
 bufferevent_getfd(struct bufferevent *bev)
 {