Bug#25387 - ndb: dbug assert in reference counting for event operations

- blob event operation not reference counted correctly, missing TE_ACTIVE
- add reference counting for blobs events
- make sure also blob event operations get TE_ACTIVE
- some minor cleanups + adjustment of dbug prints

storage/ndb/src/ndbapi/NdbEventOperationImpl.cpp

@@ -215,8 +215,6 @@ NdbEventOperationImpl::~NdbEventOperationImpl()
     DBUG_VOID_RETURN;
 
   stop();
-  // m_bufferHandle->dropSubscribeEvent(m_bufferId);
-  ; // ToDo? We should send stop signal here
   
   if (theMainOp == NULL)
   {
@@ -428,7 +426,7 @@ NdbEventOperationImpl::getBlobHandle(const NdbColumnImpl *tAttrInfo, int n)
 
       // create blob event operation
       tBlobOp =
-        m_ndb->theEventBuffer->createEventOperation(*blobEvnt, m_error);
+        m_ndb->theEventBuffer->createEventOperationImpl(*blobEvnt, m_error);
       if (tBlobOp == NULL)
         DBUG_RETURN(NULL);
 
@@ -561,6 +559,8 @@ NdbEventOperationImpl::execute_nolock()
   m_state= EO_EXECUTING;
   mi_type= m_eventImpl->mi_type;
   m_ndb->theEventBuffer->add_op();
+  m_ref_count++;
+  DBUG_PRINT("info", ("m_ref_count: %u for op: %p", m_ref_count, this));
   int r= NdbDictionaryImpl::getImpl(*myDict).executeSubscribeEvent(*this);
   if (r == 0) {
     if (theMainOp == NULL) {
@@ -568,19 +568,24 @@ NdbEventOperationImpl::execute_nolock()
       NdbEventOperationImpl* blob_op = theBlobOpList;
       while (blob_op != NULL) {
         r = blob_op->execute_nolock();
-        if (r != 0)
+        if (r != 0) {
           break;
+        }
+        // blob event op now holds reference
+        // cleared by TE_STOP or TE_CLUSTER_FAILURE
+        m_ref_count++;
+        DBUG_PRINT("info", ("m_ref_count: %u for op: %p", m_ref_count, this));
         blob_op = blob_op->m_next;
       }
     }
     if (r == 0)
     {
-      m_ref_count++;
-      DBUG_PRINT("info", ("m_ref_count: %u for op: %p", m_ref_count, this));
       DBUG_RETURN(0);
     }
   }
   //Error
+  m_ref_count--;
+  DBUG_PRINT("info", ("m_ref_count: %u for op: %p", m_ref_count, this));
   m_state= EO_ERROR;
   mi_type= 0;
   m_magic_number= 0;
@@ -1582,6 +1587,33 @@ NdbEventBuffer::complete_outof_order_gcis()
   ndbout_c("complete_outof_order_gcis: m_latestGCI: %lld", m_latestGCI);
 }
 
+void
+NdbEventBuffer::insert_event(NdbEventOperationImpl* impl,
+                             SubTableData &data,
+                             LinearSectionPtr *ptr,
+                             Uint32 &oid_ref)
+{
+  NdbEventOperationImpl *dropped_ev_op = m_dropped_ev_op;
+  do
+  {
+    do
+    {
+      oid_ref = impl->m_oid;
+      insertDataL(impl, &data, ptr);
+      NdbEventOperationImpl* blob_op = impl->theBlobOpList;
+      while (blob_op != NULL)
+      {
+        oid_ref = blob_op->m_oid;
+        insertDataL(blob_op, &data, ptr);
+        blob_op = blob_op->m_next;
+      }
+    } while((impl = impl->m_next));
+    impl = dropped_ev_op;
+    dropped_ev_op = NULL;
+  } while (impl);
+}
+
+
 void
 NdbEventBuffer::report_node_connected(Uint32 node_id)
 {
@@ -1606,21 +1638,8 @@ NdbEventBuffer::report_node_connected(Uint32 node_id)
   /**
    * Insert this event for each operation
    */
-  {
   // no need to lock()/unlock(), receive thread calls this
-    NdbEventOperationImpl* impl = &op->m_impl;
-    do if (!impl->m_node_bit_mask.isclear())
-    {
-      data.senderData = impl->m_oid;
-      insertDataL(impl, &data, ptr);
-    } while((impl = impl->m_next));
-    for (impl = m_dropped_ev_op; impl; impl = impl->m_next)
-      if (!impl->m_node_bit_mask.isclear())
-      {
-        data.senderData = impl->m_oid;
-        insertDataL(impl, &data, ptr);
-      }
-  }
+  insert_event(&op->m_impl, data, ptr, data.senderData);
   DBUG_VOID_RETURN;
 }
 
@@ -1648,21 +1667,8 @@ NdbEventBuffer::report_node_failure(Uint32 node_id)
   /**
    * Insert this event for each operation
    */
-  {
   // no need to lock()/unlock(), receive thread calls this
-    NdbEventOperationImpl* impl = &op->m_impl;
-    do if (!impl->m_node_bit_mask.isclear())
-    {
-      data.senderData = impl->m_oid;
-      insertDataL(impl, &data, ptr);
-    } while((impl = impl->m_next));
-    for (impl = m_dropped_ev_op; impl; impl = impl->m_next)
-      if (!impl->m_node_bit_mask.isclear())
-      {
-        data.senderData = impl->m_oid;
-        insertDataL(impl, &data, ptr);
-      }
-  }
+  insert_event(&op->m_impl, data, ptr, data.senderData);
   DBUG_VOID_RETURN;
 }
 
@@ -1693,21 +1699,8 @@ NdbEventBuffer::completeClusterFailed()
   /**
    * Insert this event for each operation
    */
-  {
   // no need to lock()/unlock(), receive thread calls this
-    NdbEventOperationImpl* impl = &op->m_impl;
-    do if (!impl->m_node_bit_mask.isclear())
-    {
-      data.senderData = impl->m_oid;
-      insertDataL(impl, &data, ptr);
-    } while((impl = impl->m_next));
-    for (impl = m_dropped_ev_op; impl; impl = impl->m_next)
-      if (!impl->m_node_bit_mask.isclear())
-      {
-        data.senderData = impl->m_oid;
-        insertDataL(impl, &data, ptr);
-      }
-  }
+  insert_event(&op->m_impl, data, ptr, data.senderData);
   
   /**
    *  Release all GCI's with m_gci > gci
@@ -1797,17 +1790,36 @@ NdbEventBuffer::insertDataL(NdbEventOperationImpl *op,
     {
     case NdbDictionary::Event::_TE_NODE_FAILURE:
       op->m_node_bit_mask.clear(SubTableData::getNdbdNodeId(ri));
+      DBUG_PRINT("info",
+                 ("_TE_NODE_FAILURE: m_ref_count: %u for op: %p id: %u",
+                  op->m_ref_count, op, SubTableData::getNdbdNodeId(ri)));
       break;
     case NdbDictionary::Event::_TE_ACTIVE:
       op->m_node_bit_mask.set(SubTableData::getNdbdNodeId(ri));
       // internal event, do not relay to user
+      DBUG_PRINT("info",
+                 ("_TE_ACTIVE: m_ref_count: %u for op: %p id: %u",
+                  op->m_ref_count, op, SubTableData::getNdbdNodeId(ri)));
       DBUG_RETURN_EVENT(0);
       break;
     case NdbDictionary::Event::_TE_CLUSTER_FAILURE:
+      if (!op->m_node_bit_mask.isclear())
+      {
         op->m_node_bit_mask.clear();
         DBUG_ASSERT(op->m_ref_count > 0);
         op->m_ref_count--;
-      DBUG_PRINT("info", ("m_ref_count: %u for op: %p", op->m_ref_count, op));
+        DBUG_PRINT("info", ("_TE_CLUSTER_FAILURE: m_ref_count: %u for op: %p",
+                            op->m_ref_count, op));
+        if (op->theMainOp)
+        {
+          // blob event op, need to clear ref count in main op
+          DBUG_ASSERT(op->m_ref_count == 0);
+          DBUG_ASSERT(op->theMainOp->m_ref_count > 0);
+          op->theMainOp->m_ref_count--;
+          DBUG_PRINT("info", ("m_ref_count: %u for op: %p",
+                              op->theMainOp->m_ref_count, op->theMainOp));
+        }
+      }
       break;
     case NdbDictionary::Event::_TE_STOP:
       op->m_node_bit_mask.clear(SubTableData::getNdbdNodeId(ri));
@@ -1815,7 +1827,17 @@ NdbEventBuffer::insertDataL(NdbEventOperationImpl *op,
       {
         DBUG_ASSERT(op->m_ref_count > 0);
         op->m_ref_count--;
-        DBUG_PRINT("info", ("m_ref_count: %u for op: %p", op->m_ref_count, op));
+        DBUG_PRINT("info", ("_TE_STOP: m_ref_count: %u for op: %p",
+                            op->m_ref_count, op));
+        if (op->theMainOp)
+        {
+          // blob event op, need to clear ref count in main op
+          DBUG_ASSERT(op->m_ref_count == 0);
+          DBUG_ASSERT(op->theMainOp->m_ref_count > 0);
+          op->theMainOp->m_ref_count--;
+          DBUG_PRINT("info", ("m_ref_count: %u for op: %p",
+                              op->theMainOp->m_ref_count, op->theMainOp));
+        }
       }
       break;
     default:
@@ -2639,10 +2661,10 @@ NdbEventBuffer::createEventOperation(const char* eventName,
 }
 
 NdbEventOperationImpl*
-NdbEventBuffer::createEventOperation(NdbEventImpl& evnt,
+NdbEventBuffer::createEventOperationImpl(NdbEventImpl& evnt,
                                          NdbError &theError)
 {
-  DBUG_ENTER("NdbEventBuffer::createEventOperation [evnt]");
+  DBUG_ENTER("NdbEventBuffer::createEventOperationImpl");
   NdbEventOperationImpl* tOp= new NdbEventOperationImpl(m_ndb, evnt);
   if (tOp == 0)
   {

storage/ndb/src/ndbapi/NdbEventOperationImpl.hpp

@@ -436,7 +436,7 @@ public:
   Vector<Gci_container_pod> m_active_gci;
   NdbEventOperation *createEventOperation(const char* eventName,
 					  NdbError &);
-  NdbEventOperationImpl *createEventOperation(NdbEventImpl& evnt,
+  NdbEventOperationImpl *createEventOperationImpl(NdbEventImpl& evnt,
                                                   NdbError &);
   void dropEventOperation(NdbEventOperation *);
   static NdbEventOperationImpl* getEventOperationImpl(NdbEventOperation* tOp);
@@ -541,6 +541,11 @@ public:
 #endif
 
 private:
+  void insert_event(NdbEventOperationImpl* impl,
+                    SubTableData &data,
+                    LinearSectionPtr *ptr,
+                    Uint32 &oid_ref);
+  
   int expand(unsigned sz);
 
   // all allocated data