fix(network_monitor): Delete previously allocated events in contiki

Now events are forwarded to C++ handler functions by reference, instead of
pointers, it is safer to avoid potential use on null pointers.

So now on, previously allocated (in post) user data are freed just after
handling them.

I am assuming that once events are posted, the owner is the contiki
event loop, which should free events data once consumed by handler.

In other works contiki is managing the lifecyle of user data.

Note that once event if processed, the address still remain in contiki
queue but no more referenced since the queue pointer is moving to the
next one.

A later change for contiki can explicitly set the consumed pointer to
null in consumed queue cell.

Relate-to: UIC-3659
Relate-to: SiliconLabsSoftware/z-wave-engine-application-layer#17
Signed-off-by: Philippe Coval <[email protected]>

Author: rzr

applications/zpc/components/network_monitor/src/network_monitor.cpp

@@ -716,49 +716,44 @@ static void
   network_initialized = true;
 }
 
-static void network_monitor_handle_event_network_ready(network_data *event_data)
+static void network_monitor_handle_event_network_ready(network_data const &event_data)
 {
   // Make sure that UNID / ZPC UNID are configured correctly.
-  zwave_unid_set_home_id(event_data->home_id);
-  zwave_unid_from_node_id(event_data->node_id, zpc_unid);
+  zwave_unid_set_home_id(event_data.home_id);
+  zwave_unid_from_node_id(event_data.node_id, zpc_unid);
 
   // Save our updated granted keys/KEX fail
   network_monitor_create_attribute_store_network_nodes(
-    event_data->granted_keys,
-    event_data->kex_fail_type);
+    event_data.granted_keys,
+    event_data.kex_fail_type);
 
   // Pause node resolution on any other network than ours in the Attribute Store.
   network_monitor_activate_network_resolution(true);
-
-  delete event_data;
 }
 
 static void network_monitor_handle_event_node_id_assigned(
-  node_id_assigned_event_data *event_data)
+  node_id_assigned_event_data const &event_data)
 {
   network_monitor_add_attribute_store_node(
-    event_data->node_id,
+    event_data.node_id,
     ZCL_NODE_STATE_NETWORK_STATUS_COMMISIONING_STARTED);
-  zwave_store_inclusion_protocol(event_data->node_id,
-                                 event_data->inclusion_protocol);
-
-  delete event_data;
+  zwave_store_inclusion_protocol(event_data.node_id,
+                                 event_data.inclusion_protocol);
 }
 
 static void
-  network_monitor_handle_event_node_added(node_added_event_data *event_data)
+  network_monitor_handle_event_node_added(node_added_event_data const &event_data)
 {
   // Attribute store node should already exist, but in case NODE_ID_ASSIGNED_EVENT
   // did not happen before this event, we ensure the node exists in the attribute store.
-  network_monitor_update_new_node_attribute_store(*event_data);
+  network_monitor_update_new_node_attribute_store(event_data);
 
-  zwave_store_inclusion_protocol(event_data->node_id,
-                                 event_data->inclusion_protocol);
+  zwave_store_inclusion_protocol(event_data.node_id,
+                                 event_data.inclusion_protocol);
 
   // Finally we want to update our local cache of the node list:
   zwave_network_management_get_network_node_list(current_node_list);
   // TODO: Add timeout system to detect node interview failed
-  delete event_data;
 }
 
 static void network_monitor_handle_event_node_interview_initiated(
@@ -1088,18 +1083,33 @@ PROCESS_THREAD(network_monitor_process, ev, data)
         break;
 
       case NETWORK_READY_EVENT:
-        network_monitor_handle_event_network_ready(
-          static_cast<network_data *>(data));
+        if (data) {
+          network_data const *event_data
+            = static_cast<network_data const *>(data);
+          data = NULL;
+          network_monitor_handle_event_network_ready(*event_data);
+          delete event_data;  //< Allocated by network_monitor_on_network_ready
+        };
         break;
 
       case NODE_ID_ASSIGNED_EVENT:
-        network_monitor_handle_event_node_id_assigned(
-          static_cast<node_id_assigned_event_data *>(data));
+        if (data) {
+          node_id_assigned_event_data const *event_data
+            = static_cast<node_id_assigned_event_data const *>(data);
+          data = NULL;
+          network_monitor_handle_event_node_id_assigned(*event_data);
+          delete event_data;  //< Allocated by network_monitor_on_node_id_assigned
+        };
         break;
 
       case NODE_ADDED_EVENT:
-        network_monitor_handle_event_node_added(
-          static_cast<node_added_event_data *>(data));
+        if (data) {
+          node_added_event_data const *event_data
+            = static_cast<node_added_event_data const *>(data);
+          data = NULL;
+          network_monitor_handle_event_node_added(*event_data);
+          delete event_data;  //< Allocated by network_monitor_on_node_added
+        };
         break;
 
       case NODE_INTERVIEW_INITIATED_EVENT: