poll.c:dcb_close Don't call poll_remove_dcb anymore if DCB has already been removed from poll set.

mysql_backend.c, mysql_client.c free error message GWBUF after calling handleError
readconnroute.c:handleError send error message to client before returning.
readwritesplit.c:handleError don't free error message buffer anymore since the caller of handleError frees it.

server/core/dcb.c

@@ -1140,18 +1140,9 @@ dcb_close(DCB *dcb)
         /*<
         * Stop dcb's listening and modify state accordingly.
         */
-        rc = poll_remove_dcb(dcb);
+	if (dcb->state == DCB_STATE_POLLING)
-        
-        ss_dassert(dcb->state == DCB_STATE_NOPOLLING ||
-                dcb->state == DCB_STATE_ZOMBIE);
-        /**
-         * close protocol and router session
-         */
-        if (dcb->func.close != NULL)
 	{
-                dcb->func.close(dcb);
+		rc = poll_remove_dcb(dcb);
-        }
-	dcb_call_callback(dcb, DCB_REASON_CLOSE);
 
 		if (rc == 0) {
 			LOGIF(LD, (skygw_log_write(
@@ -1170,6 +1161,18 @@ dcb_close(DCB *dcb)
 				dcb,
 				STRDCBSTATE(dcb->state))));
 		}
+	}
+        ss_dassert(dcb->state == DCB_STATE_NOPOLLING ||
+                dcb->state == DCB_STATE_ZOMBIE);
+        /**
+         * close protocol and router session
+         */
+        if (dcb->func.close != NULL)
+        {
+                dcb->func.close(dcb);
+        }
+	dcb_call_callback(dcb, DCB_REASON_CLOSE);
+
         
         if (dcb->state == DCB_STATE_NOPOLLING) 
         {

server/modules/protocol/mysql_backend.c

@@ -377,7 +377,7 @@ static int gw_read_backend_event(DCB *dcb) {
                                                         dcb,
                                                         ERRACT_REPLY_CLIENT,
                                                         &succp);
-                                        
+                                        gwbuf_free(errbuf);
                                         ss_dassert(!succp);
                                         LOGIF(LD, (skygw_log_write(
                                                 LOGFILE_DEBUG,
@@ -459,6 +459,7 @@ static int gw_read_backend_event(DCB *dcb) {
                                     dcb,
                                     ERRACT_NEW_CONNECTION,
                                     &succp);
+			gwbuf_free(errbuf);
 			
                         if (!succp)
                         {
@@ -848,6 +849,7 @@ static int gw_error_backend_event(DCB *dcb)
                             dcb,
                             ERRACT_NEW_CONNECTION,
                             &succp);
+        gwbuf_free(errbuf);
 	
         /** There are not required backends available, close session. */
         if (!succp) {
@@ -1031,7 +1033,8 @@ gw_backend_hangup(DCB *dcb)
                             ERRACT_NEW_CONNECTION,
                             &succp);
         
-        /** There are not required backends available, close session. */
+	gwbuf_free(errbuf);
+        /** There are no required backends available, close session. */
         if (!succp) 
         {
 #if defined(SS_DEBUG)                
@@ -1039,7 +1042,6 @@ gw_backend_hangup(DCB *dcb)
                         LOGFILE_ERROR,
                         "Backend hangup -> closing session.")));
 #endif
-                
                 spinlock_acquire(&session->ses_lock);
                 session->state = SESSION_STATE_STOPPING;
                 spinlock_release(&session->ses_lock);
@@ -1176,6 +1178,7 @@ static int backend_write_delayqueue(DCB *dcb)
                                     dcb,
                                     ERRACT_NEW_CONNECTION,
                                     &succp);
+		gwbuf_free(errbuf);
 		
                 if (!succp)
                 {

server/modules/protocol/mysql_client.c

@@ -859,6 +859,7 @@ int gw_read_client_event(
                                                     dcb,
                                                     ERRACT_REPLY_CLIENT,
                                                     &succp);
+				gwbuf_free(errbuf);
                                 ss_dassert(!succp);
 
                                 dcb_close(dcb);

server/modules/routing/readconnroute.c

@@ -815,21 +815,33 @@ clientReply(
  * @param       action     	The action: REPLY, REPLY_AND_CLOSE, NEW_CONNECTION
  *
  */
-static  void
+static void handleError(
-handleError(
 	ROUTER           *instance,
 	void             *router_session,
 	GWBUF            *errbuf,
 	DCB              *backend_dcb,
 	error_action_t   action,
 	bool             *succp)
+
 {
-	DCB		*client = NULL;
+	DCB             *client_dcb;
 	SESSION         *session = backend_dcb->session;
-	client = session->client;
+	session_state_t sesstate;
+	
+	spinlock_acquire(&session->ses_lock);
+	sesstate = session->state;
+	client_dcb = session->client;
+	spinlock_release(&session->ses_lock);
+	ss_dassert(client_dcb != NULL);
+	
+	if (sesstate == SESSION_STATE_ROUTER_READY)
+	{
+		CHK_DCB(client_dcb);
+		client_dcb->func.write(client_dcb, gwbuf_clone(errbuf));
+	}
+	
 	/** false because connection is not available anymore */
 	*succp = false;
-	ss_dassert(client != NULL);
 }
 
 /** to be inline'd */

server/modules/routing/readwritesplit/readwritesplit.c

@@ -4023,7 +4023,7 @@ static void rwsplit_process_router_options(
  *
  * @param       instance        The router instance
  * @param       router_session  The router session
- * @param       message         The error message to reply
+ * @param       errmsgbuf       The error message to reply
  * @param       backend_dcb     The backend DCB
  * @param       action          The action: REPLY, REPLY_AND_CLOSE, NEW_CONNECTION
  * @param       succp           Result of action. 
@@ -4102,12 +4102,7 @@ static void handle_error_reply_client(
 	if (sesstate == SESSION_STATE_ROUTER_READY)
 	{
 		CHK_DCB(client_dcb);
-                client_dcb->func.write(client_dcb, errmsg);
+		client_dcb->func.write(client_dcb, gwbuf_clone(errmsg));
-        }
-        else
-        {
-                while ((errmsg=gwbuf_consume(errmsg, GWBUF_LENGTH(errmsg))) != NULL)
-                        ;
 	}
 }
 
@@ -4157,14 +4152,9 @@ static bool handle_error_new_connection(
 	{
 		DCB* client_dcb;
 		client_dcb = ses->client;
-                client_dcb->func.write(client_dcb, errmsg);
+		client_dcb->func.write(client_dcb, gwbuf_clone(errmsg));
 		bref_clear_state(bref, BREF_WAITING_RESULT);
 	}
-        else 
-        {
-                while ((errmsg=gwbuf_consume(errmsg, GWBUF_LENGTH(errmsg))) != NULL)
-                        ;
-        }
 	bref_clear_state(bref, BREF_IN_USE);
 	bref_set_state(bref, BREF_CLOSED);
 	/**