Is the C API thread-safe?

I am working on an application that spawns a thread from a modified rt_lx_main.cpp at model startup and subsequently sets parameters in the Simulink model using the C API interface. I plan on doing this at startup as well as during run time. If I do this a run time, is there any issue of data corruption, or in other words is the C-API thread safe? I only plan on running one thread that will modify parameters in the Simulink model, but would me modifying this code from a thread during run time cause any issues with what happens in the model? I'm using Embedded Coder and G++ to build the model and associated Source Code.

Answer 1

[James Tursa]

In general, mex API functions are not thread safe. In particular, any functions that allocate/deallocate memory (e.g. the mxCreateEtc, mxDestroyArray, mxFree, etc) are not thread safe. API functions that only "inquire" (e.g. mxGetPr, mxGetPi, etc) would probably be thread safe.

Answer 2

[Maxwell Bezold]

So I am not talking about mex functions running natively in Simulink, but rather about accessing memory in the model through the C-API interface on a real time Embedded Coder target. (e.g. the parameters made accessible when I click the signals and parameter boxes in the attached photo)