Archived OpenModelica forums. Posting is disabled.

Alternative forums include GitHub discussions or StackOverflow (make sure to read the Stack Overflow rules; you need to have well-formed questions)


Forgot password? | Forgot username? | Register
Page Start Prev 1 Next End

Use of Records in external C code

#11136  Permalink Top

Use of Records in external C code

Oct-04-21 18:32:31

Hello,
I created a small test example for using a modelica record in external C functions. My goal is to initialise the record in Modelica and hand it over to C by reference. Since the reference is in C I would assume, that data changes also for Modelica. Unfortunately this is not the result of my test example.

My C code is the following:

Code:


typedef struct

{

    double a, b, c;

}threeValues;



void add_c(void*);





void add_c(void* in){

    threeValues* out = (threeValues*)in;

    out->a += 2.;

    out->b += 2.;

    out->c += 2.;

}

The modelica Code is:

Code:


model structTest

  threeValues abc(a(start=1.), b(start=2.), c(start=3.));



  record threeValues

    Real a, b, c;

    annotation(

      Icon(coordinateSystem(extent = {{-200, -200}, {200, 200}})),

      Diagram(coordinateSystem(extent = {{-200, -200}, {200, 200}})));

  end threeValues;



  function add

    output threeValues abc;



    external "C" 

      add_c(abc) annotation(

      IncludeDirectory = "modelica://structTest",

      Include = "#include \"add_two.c\"");

    annotation(

      Icon(coordinateSystem(extent = {{-200, -200}, {200, 200}})),

      Diagram(coordinateSystem(extent = {{-200, -200}, {200, 200}})));

  end add;

equation

  abc = add();

  annotation(

    Icon(coordinateSystem(extent = {{-200, -200}, {200, 200}})),

    Diagram(coordinateSystem(extent = {{-200, -200}, {200, 200}})));

end structTest;

I already tested various variants, e.g. with algorithm section, but the data in Modelica is either Nan or fix at the initial values.
Has somebody an idea what I am doing wrong?

Page Start Prev 1 Next End
Previous topic
Next topic
There are 0 guests and 0 other users also viewing this topic
You are here: