Bug #385 http://bugs.skysql.com/show_bug.cgi?id=385

dcb.c:dcb_write accept also dcb state DCB_STATE_NOPOLLING since it only means that dcb has been removed from epoll set but it is still possible to write to it.

Bug #384 http://bugs.skysql.com/show_bug.cgi?id=384
session.h:added new state for SESSION, SESSION_STATE_ROUTER_READY which follows SESSION_STATE_READY. The difference is that ROUTER_READY is set only after router session is successfully created while READY means that session still lacks router.
session.c:set SESSION_STATE_ROUTER_READY when router is created.
mysql_backend.c:gw_read_backend_event, added SESSION_STATE_ROUTER_READY check before router session is closed. Changed chec kso that it doesn't block in infinite loop (although it shouldn't be possible anyway).
mysql_backend.c:gw_error_backend_event, added similar check before session is closed.

query_classifier/query_classifier.cc

@@ -585,9 +585,10 @@ static skygw_query_type_t resolve_query_type(
                                         LOGIF(LD, (skygw_log_write(
                                                 LOGFILE_DEBUG,
                                                 "%lu [resolve_query_type] "
-                                                "Unknown functype. Something "
+                                                "Unknown functype %d. Something "
                                                 "has gone wrong.",
-                                                pthread_self())));
+                                                pthread_self(),
+                                                ftype)));
                                         break;
                                 } /**< switch */
                                 /**< Set new query type */

server/core/dcb.c

@@ -659,7 +659,8 @@ dcb_write(DCB *dcb, GWBUF *queue)
         if (queue == NULL ||
             (dcb->state != DCB_STATE_ALLOC &&
              dcb->state != DCB_STATE_POLLING &&
-             dcb->state != DCB_STATE_LISTENING))
+             dcb->state != DCB_STATE_LISTENING &&
+             dcb->state != DCB_STATE_NOPOLLING))
         {
                 return 0;
         }

server/core/session.c

@@ -105,7 +105,7 @@ session_alloc(SERVICE *service, DCB *client_dcb)
 	session->refcount = 1;
         /*<
          * This indicates that session is ready to be shared with backend
-         * DCBs.
+         * DCBs. Note that this doesn't mean that router is initialized yet!
          */
         session->state = SESSION_STATE_READY;
         
@@ -145,6 +145,7 @@ session_alloc(SERVICE *service, DCB *client_dcb)
                 }
         }
 	spinlock_acquire(&session_spin);
+        session->state = SESSION_STATE_ROUTER_READY;
 	session->next = allSessions;
 	allSessions = session;
 	spinlock_release(&session_spin);

server/include/session.h

@@ -50,11 +50,12 @@ typedef struct {
 } SESSION_STATS;
 
 typedef enum {
-    SESSION_STATE_ALLOC,
+    SESSION_STATE_ALLOC,            /*< for all sessions */
-    SESSION_STATE_READY,
+    SESSION_STATE_READY,            /*< for router session */
-    SESSION_STATE_LISTENER,
+    SESSION_STATE_ROUTER_READY,     /*< for router session */
-    SESSION_STATE_LISTENER_STOPPED,
+    SESSION_STATE_LISTENER,         /*< for listener session */
-    SESSION_STATE_FREE
+    SESSION_STATE_LISTENER_STOPPED, /*< for listener session */
+    SESSION_STATE_FREE              /*< for all sessions */
 } session_state_t;
 
 /**

server/modules/protocol/mysql_backend.c

@@ -299,17 +299,31 @@ static int gw_read_backend_event(DCB *dcb) {
                                                 dcb->delayq,
                                                 gwbuf_length(dcb->delayq));
                                 }
-                                ss_dassert(session->state == SESSION_READY);
+
-                                /**
+                                while (session->state != SESSION_STATE_ROUTER_READY)
-                                 * vraa : errorHandle
-                                 * rsession may be NULL if session is being created
-                                 * in parallel by another thread.
-                                 */
-                                while(session->router_session == NULL)
                                 {                                        
+                                        ss_dassert(
+                                                session->state == SESSION_STATE_READY ||
+                                                session->state ==
+                                                SESSION_STATE_ROUTER_READY);
+                                        /**
+                                         * Session shouldn't be NULL at this point
+                                         * anymore. Just checking..
+                                         */
+                                        if (session->client->session == NULL)
+                                        {
+                                                rc = 1;
+                                                goto return_with_lock;
+                                        }
                                         usleep(1);
                                 }
+                                /**
+                                 * rsession shouldn't be NULL since session
+                                 * state indicates that it was initialized
+                                 * successfully.
+                                 */
                                 rsession = session->router_session;
+                                ss_dassert(rsession != NULL);
                                 
                                 LOGIF(LD, (skygw_log_write_flush(
                                         LOGFILE_DEBUG,
@@ -596,17 +610,19 @@ static int gw_error_backend_event(DCB *dcb) {
 		rc = 1;
 	}
 	LOGIF(LE, (skygw_log_write_flush(
-		LOGFILE_ERROR,
+		LOGFILE_DEBUG,
 		"%lu [gw_error_backend_event] Some error occurred in backend. "
                 "rc = %d",
 		pthread_self(),
                 rc)));
+
+        if (session->state == SESSION_STATE_ROUTER_READY)
+        {
                 rsession = session->router_session;
-        ss_dassert(rsession != NULL);
                 /*<
-         * vraa : errorHandle
                  * rsession should never be NULL here.
                  */
+                ss_dassert(rsession != NULL);
                 LOGIF(LD, (skygw_log_write_flush(
                                    LOGFILE_DEBUG,
                                    "%lu [gw_error_backend_event] "
@@ -615,7 +631,7 @@ static int gw_error_backend_event(DCB *dcb) {
                                    pthread_self())));
                 
                 router->closeSession(router_instance, rsession);
-        
+        }
 	return rc;
 }
 

server/modules/routing/readwritesplit/readwritesplit.c

@@ -315,7 +315,6 @@ static void* newSession(
         client_rses->master_dcb = dcb_connect(be_master->backend_server,
                                              session,
                                              be_master->backend_server->protocol);
-
         if (client_rses->master_dcb == NULL)
 	{
                 /** Close slave connection first. */
@@ -543,7 +542,7 @@ static int routeQuery(
 
         if (rses_is_closed || (master_dcb == NULL && slave_dcb == NULL))
         {
-                LOGIF(LE, (skygw_log_write(
+                LOGIF(LE, (skygw_log_write_flush(
                         LOGFILE_ERROR,
                         "Error: Failed to route %s:%s:\"%s\" to backend server. "
                         "%s.",