[Scilab-Dev] New xcos blocks executing scilab primitive functions

[Eric GERNOT]

Hi Clément, 

 

I hope you may help me spare some tests !

 

Regarding Scifunc blocks, in sciblk4, createblklist() uses vartosci(..) to reshape the inptr, yet it does only copy the adresses in a new table of pointers, not the actual data, isn't it? Do you thing this address copying is the time consumming operation ?

 

I found 2 stranges things:

1) vartosci(..) creates a List with appends in a for loop, and the data is stored in a vector m_plData. That means each time the vector capacity is reached, it "reallocates it in order to grow in size when new elements are inserted, which implies allocating a new array and moving all elements to it".


Is a memory allocation strategy defined somewhere in Scilab for TList, List and Typed_list.


 

2) createblklist(...) creates a TList whose values are also stored in a vector container m_plData, which is also dynamically allocated and may be recreated each time capacity is reached, by the append method.

 

Thus, in sciblk4, could we call static types::InternalType* pIT = createblklist(...) and in.push_back(pIT) only when flag is on initialization, so that all Lists are created once and only updated at each iteration ? Would it help ? That would require to rewrite vartosci() and createblklist() with a iterator approach instead of append.


 

Regards, 

Eric

 

 

 

> Message du 09/04/18 09:37
> De : "Clément David" 
> A : "dev at lists.scilab.org" 
> Copie à : 
> Objet : Re: [Scilab-Dev] New xcos blocks executing scilab primitive functions
> 


> To call Scilab script within the sciblk2 [1] and sciblk4 [2] blocks we are indeed using the Scilab
> C++ API, the performance overhead is quiet clear as we are currently allocating Scilab types::Double
> or a types::MList through createblklist() for each output on each simulation step.
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