MINOR: connection: use MT_LIST_ADDQ() to add connections to idle lists

When a connection is added to an idle list, it's already detached and
cannot be seen by two threads at once, so there's no point using
TRY_ADDQ, there will never be any conflict. Let's just use the cheaper
ADDQ.

include/haproxy/server.h

@@ -273,11 +273,11 @@ static inline int srv_add_to_idle_list(struct server *srv, struct connection *co
 		conn->idle_time = now_ms;
 		if (is_safe) {
 			conn->flags = (conn->flags & ~CO_FL_LIST_MASK) | CO_FL_SAFE_LIST;
-			MT_LIST_TRY_ADDQ(&srv->safe_conns[tid], (struct mt_list *)&conn->list);
+			MT_LIST_ADDQ(&srv->safe_conns[tid], (struct mt_list *)&conn->list);
 			_HA_ATOMIC_ADD(&srv->curr_safe_nb, 1);
 		} else {
 			conn->flags = (conn->flags & ~CO_FL_LIST_MASK) | CO_FL_IDLE_LIST;
-			MT_LIST_TRY_ADDQ(&srv->idle_conns[tid], (struct mt_list *)&conn->list);
+			MT_LIST_ADDQ(&srv->idle_conns[tid], (struct mt_list *)&conn->list);
 			_HA_ATOMIC_ADD(&srv->curr_idle_nb, 1);
 		}
 		_HA_ATOMIC_ADD(&srv->curr_idle_thr[tid], 1);

src/backend.c

@@ -1345,7 +1345,7 @@ int connect_server(struct stream *s)
 				if (tokill_conn) {
 					/* We got one, put it into the concerned thread's to kill list, and wake it's kill task */
 
-					MT_LIST_TRY_ADDQ(&idle_conns[i].toremove_conns,
+					MT_LIST_ADDQ(&idle_conns[i].toremove_conns,
 					    (struct mt_list *)&tokill_conn->list);
 					task_wakeup(idle_conns[i].cleanup_task, TASK_WOKEN_OTHER);
 					HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[tid].takeover_lock);

src/mux_fcgi.c

@@ -2956,9 +2956,9 @@ static struct task *fcgi_io_cb(struct task *t, void *ctx, unsigned short status)
 		struct server *srv = objt_server(conn->target);
 
 		if (conn_in_list == CO_FL_SAFE_LIST)
-			MT_LIST_TRY_ADDQ(&srv->safe_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->safe_conns[tid], &conn->list);
 		else
-			MT_LIST_TRY_ADDQ(&srv->idle_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->idle_conns[tid], &conn->list);
 	}
 	return NULL;
 }

src/mux_h1.c

@@ -2265,9 +2265,9 @@ static struct task *h1_io_cb(struct task *t, void *ctx, unsigned short status)
 		struct server *srv = objt_server(conn->target);
 
 		if (conn_in_list == CO_FL_SAFE_LIST)
-			MT_LIST_TRY_ADDQ(&srv->safe_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->safe_conns[tid], &conn->list);
 		else
-			MT_LIST_TRY_ADDQ(&srv->idle_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->idle_conns[tid], &conn->list);
 	}
 	return NULL;
 }

src/mux_h2.c

@@ -3565,9 +3565,9 @@ static struct task *h2_io_cb(struct task *t, void *ctx, unsigned short status)
 		struct server *srv = objt_server(conn->target);
 
 		if (conn_in_list == CO_FL_SAFE_LIST)
-			MT_LIST_TRY_ADDQ(&srv->safe_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->safe_conns[tid], &conn->list);
 		else
-			MT_LIST_TRY_ADDQ(&srv->idle_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->idle_conns[tid], &conn->list);
 	}
 
 leave:

src/ssl_sock.c

@@ -5676,9 +5676,9 @@ static struct task *ssl_sock_io_cb(struct task *t, void *context, unsigned short
 		struct server *srv = objt_server(conn->target);
 
 		if (conn_in_list == CO_FL_SAFE_LIST)
-			MT_LIST_TRY_ADDQ(&srv->safe_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->safe_conns[tid], &conn->list);
 		else
-			MT_LIST_TRY_ADDQ(&srv->idle_conns[tid], &conn->list);
+			MT_LIST_ADDQ(&srv->idle_conns[tid], &conn->list);
 	}
 	return NULL;
 }