Why aren't multiple simultaneous reliable publish messages for the same model handle allowed?

Question

Hi, 
 I'm using Mesh SDK v3.2 and I've created my own custom client & server model. My client model can call several types of monitoring GET messages to the server model, which answers with corresponding STATUS messages. I'd like to call several of these GET messages simultaneously within the publish timer timeout of the client model. However, it seems that I can't call access_model_reliable_publish multiple times simultaneously for the same model_handle? Why is that? Is this something that is going to be allowed in future versions? Or am I missing something from standardization? Because it does seems that I can enlarge the context space for more reliable structures but that the code still limits to only 1 reliable structure per model_handle being "busy" at the same time (looking at available_context_get in access_reliable.c ). 
 Kind regards, 
 Mathias

tesc · Accepted Answer

Hi, 
 First of all, sorry for the delay. (It was my fault, I missed the notification from our issue tracker.) 
 Response from our developers: 
 The access layer as such does not have any restriction as per specification. However, as the access layer is tied closely with the model layer it does not have a queuing mechanism for queuing up multiple model messages. Since there is close tie-up between the access layer and models, implementing queuing does not make sense. Send one message -> wait for the response -> send next message. In request-response based message exchanges queuing at the access layer will not help at all 
 They also suggest that models be small self-contained entities that do only one thing at a time. Typically if you need queues at the model/access layer, it could be better to split it up into different models instead of having one model that requires access layer queuing mechanisms. 
 Would it make sense, for your use case, to split the models? E.g. in our light switch examples, we use one model for each light switch. While in that example the models are identical (all on/off models), the same pattern may be used for when the status data differs. 
 Alternatively, does it make sense, if in any case you ask for the different data at the same time, to merge this into one GET, with a response containing all the status data? 
 Regards, Terje

Why aren't multiple simultaneous reliable publish messages for the same model handle allowed?

Top Replies