How to clear custom c-code variables from memory between simulation runs?
5 views (last 30 days)
Show older comments
Hello
I have a Simulink model that has lots of custom c-code functions in it. It seems that in Simulink the custom code variables stay in the memory after the simulation has ended.
For example I have following code:
int i = 0;
int foo() {
i = i + 1;
return i;
}
The value of i does not reset to 0 between simulation runs. The value of i increments by 1 for everytime I run the simulation.
How do I unload the variables of custom c-code from the memory?
Thanks in advance.
0 Comments
Answers (3)
Birdman
on 28 Mar 2018
You can use StartFcn and StopFcn callbacks in File->Model Properties->Model Properties->Callbacks to add and delete custom C code.
9 Comments
Birdman
on 28 Mar 2018
In my code, i is defined within the function and at every simulation, it is initialized to 0, equivalent to clearing it at the end of the simulation.
Adam Johnson
on 2 Feb 2022
Has this question be addressed? I am getting the same issue and need a fix.
0 Comments
Pawel Hanczur
on 12 Sep 2022
Hello.
I was struggling a lot with this strange issue. Here is the workaround:
In m-function you'll should have the contruction of sort fo this:
persistent Is_First_Cycle;
if isempty(Is_First_Cycle)
Is_First_Cycle=1;
else
Is_First_Cycle=0;
end
Then you pass the flag to the to the C code:
coder.ceval('my_C_prg', Is_First_Cycle,...);
Then in C code you can add something like this:
//my_C_prg.c
void C_prg(double Is_First_Cycle, ...)
{
double var1;
double* refVar1;
double* refVar2;
if (Is_First_Cycle==1)
{var1=0;
VarsIni (&refVar1, &refVar2,...);
}
...
What moreover when i was trying to set pointer variable in main function for example:
void C_prg(double Is_First_Cycle,..., ..., ...)
{
double var1;
double* refVar1;
double* refVar2;
if (Is_First_Cycle==1)
{var1=0;
refVar1[0]=1;
refVar2[0]=3;
}
}
The all Matlab crashed. And funny thing is that, that when you I used the first construction (with inner VarsIni function), everything worked fine.
Best regards.
0 Comments
See Also
Categories
Find more on Simulink Functions in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!