fix dfc server thread core when stop

src/observer/ob_server.cpp

@@ -606,6 +606,11 @@ int ObServer::stop()
   }
   LOG_WARN("distributed scheduler manager has stopped");
 
+  if (OB_NOT_NULL(dtl::ObDtl::instance())) {
+    DTL.stop();
+  }
+  LOG_INFO("sqldtl stop");
+
   LOG_INFO("begin stop GDS");
   GDS.stop();
   LOG_WARN("GDS stopped");

src/sql/dtl/ob_dtl.cpp

@@ -288,6 +288,11 @@ int ObDtl::init()
   return ret;
 }
 
+void ObDtl::stop()
+{
+  dfc_server_.stop();
+}
+
 int ObDtl::create_channel(
     uint64_t tenant_id, uint64_t chid, const ObAddr& peer, ObDtlChannel*& chan, ObDtlFlowControl* dfc)
 {

src/sql/dtl/ob_dtl.h

@@ -95,6 +95,7 @@ public:
 
   // Initialize DTL service.
   int init();
+  void stop();
 
   ObDtlRpcProxy& get_rpc_proxy();
   const ObDtlRpcProxy& get_rpc_proxy() const;

src/sql/dtl/ob_dtl_fc_server.cpp

@@ -399,8 +399,17 @@ int ObDfcServer::init()
   return ret;
 }
 
+void ObDfcServer::stop()
+{
+  TG_STOP(lib::TGDefIDs::DtlDfc);
+  LOG_INFO("DtlDfc timer stopped");
+}
+
 void ObDfcServer::destroy()
-{}
+{
+  TG_DESTROY(lib::TGDefIDs::DtlDfc);
+  LOG_INFO("DtlDfc timer destroy");
+}
 
 void ObDfcServer::runTimerTask()
 {

src/sql/dtl/ob_dtl_fc_server.h

@@ -170,6 +170,7 @@ public:
   }
 
   int init();
+  void stop();
   void destroy();
   // check tenant dfc resource every 10 seconds
   void runTimerTask();