MINOR: connections: Use BUG_ON() to enforce rules in subscribe/unsubscribe.

It is not legal to subscribe if we're already subscribed, or to unsubscribe
if we did not subscribe, so instead of trying to handle those cases, just
assert that it's ok using the new BUG_ON() macro.

diff --git a/src/connection.c b/src/connection.c
index adedb41..908d098 100644 (file)
--- a/src/connection.c
+++ b/src/connection.c
@@ -319,18 +319,16 @@ int conn_unsubscribe(struct connection *conn, void *xprt_ctx, int event_type, vo
 
        if (event_type & SUB_RETRY_RECV) {
                sw = param;
-               if (sw->events & SUB_RETRY_RECV) {
-                       conn->recv_wait = NULL;
-                       sw->events &= ~SUB_RETRY_RECV;
-               }
+               BUG_ON(conn->recv_wait != sw);
+               conn->recv_wait = NULL;
+               sw->events &= ~SUB_RETRY_RECV;
                __conn_xprt_stop_recv(conn);
        }
        if (event_type & SUB_RETRY_SEND) {
                sw = param;
-               if (sw->events & SUB_RETRY_SEND) {
-                       conn->send_wait = NULL;
-                       sw->events &= ~SUB_RETRY_SEND;
-               }
+               BUG_ON(conn->send_wait != sw);
+               conn->send_wait = NULL;
+               sw->events &= ~SUB_RETRY_SEND;
                __conn_xprt_stop_send(conn);
        }
        conn_update_xprt_polling(conn);
@@ -343,19 +341,17 @@ int conn_subscribe(struct connection *conn, void *xprt_ctx, int event_type, void
 
        if (event_type & SUB_RETRY_RECV) {
                sw = param;
-               if (!(sw->events & SUB_RETRY_RECV)) {
-                       sw->events |= SUB_RETRY_RECV;
-                       conn->recv_wait = sw;
-               }
+               BUG_ON(conn->recv_wait != NULL || (sw->events & SUB_RETRY_RECV));
+               sw->events |= SUB_RETRY_RECV;
+               conn->recv_wait = sw;
                event_type &= ~SUB_RETRY_RECV;
                __conn_xprt_want_recv(conn);
        }
        if (event_type & SUB_RETRY_SEND) {
                sw = param;
-               if (!(sw->events & SUB_RETRY_SEND)) {
-                       sw->events |= SUB_RETRY_SEND;
-                       conn->send_wait = sw;
-               }
+               BUG_ON(conn->send_wait != NULL || (sw->events & SUB_RETRY_SEND));
+               sw->events |= SUB_RETRY_SEND;
+               conn->send_wait = sw;
                event_type &= ~SUB_RETRY_SEND;
                __conn_xprt_want_send(conn);
        }