From 2e50985f359ddca61ce1839b480fb46002931d40 Mon Sep 17 00:00:00 2001
From: Shawn <506895667@qq.com>
Date: Fri, 24 Mar 2023 11:40:36 +0800
Subject: [PATCH] fix: update testcase t_discard_session_race

---
 src/emqx_cm.erl        | 4 ++++
 test/emqx_cm_SUITE.erl | 9 ++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/emqx_cm.erl b/src/emqx_cm.erl
index dc9aa6c3e..1c14fec43 100644
--- a/src/emqx_cm.erl
+++ b/src/emqx_cm.erl
@@ -84,6 +84,10 @@
         , get_connected_client_count/0
         ]).
 
+-ifdef(TEST).
+-export([request_stepdown/3]).
+-endif.
+
 -type(chan_pid() :: pid()).
 
 %% Tables for channel management.
diff --git a/test/emqx_cm_SUITE.erl b/test/emqx_cm_SUITE.erl
index 1e075efe1..122ca81f5 100644
--- a/test/emqx_cm_SUITE.erl
+++ b/test/emqx_cm_SUITE.erl
@@ -314,16 +314,19 @@ flush_emqx_pool() ->
 
 t_discard_session_race(_) ->
     ClientId = rand_client_id(),
+    ConnMod = emqx_ws_connection,
     ?check_trace(
        begin
          #{conninfo := ConnInfo0} = ?ChanInfo,
-         ConnInfo = ConnInfo0#{conn_mod := emqx_ws_connection},
+         ConnInfo = ConnInfo0#{conn_mod := ConnMod},
          {Pid, Ref} = spawn_monitor(fun() -> receive stop -> exit(normal) end end),
          ok = emqx_cm:register_channel(ClientId, Pid, ConnInfo),
          Pid ! stop,
          receive {'DOWN', Ref, process, Pid, normal} -> ok end,
-         ok = emqx_cm:discard_session(ClientId),
-         {ok, _} = ?block_until(#{?snk_kind := "session_already_gone", pid := Pid}, 1000)
+         %% Here we simulate the situation where we are going to emqx_cm:discard_session/1
+         %% but the session has died.
+         emqx_cm:request_stepdown(discard, ConnMod, Pid),
+         {ok, _} = ?block_until(#{?snk_kind := "session_already_gone", stale_pid := Pid}, 2000)
        end,
        fun(_, _) ->
                true