From 990514a048933c1ba31507e01e8f685075d1dcec Mon Sep 17 00:00:00 2001
From: JianBo He <heeejianbo@gmail.com>
Date: Thu, 30 Dec 2021 18:29:19 +0800
Subject: [PATCH] fix(gw): stop xml_object_db process synchronously

---
 apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl b/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl
index 47ed722b1..f4d73879d 100644
--- a/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl
+++ b/apps/emqx_gateway/src/lwm2m/emqx_lwm2m_impl.erl
@@ -92,7 +92,7 @@ on_gateway_update(Config, Gateway, GwState = #{ctx := Ctx}) ->
 
 on_gateway_unload(_Gateway = #{ name := GwName,
                                 config := Config
-                              }, _GwState = #{registry := RegPid}) ->
-    exit(RegPid, kill),
+                              }, _GwState = #{registry := _RegPid}) ->
+    _ = try emqx_lwm2m_xml_object_db:stop() catch _ : _  -> ok end,
     Listeners = emqx_gateway_utils:normalize_config(Config),
     emqx_gateway_utils:stop_listeners(GwName, Listeners).