CUDA simulation vs. visualization CUDA-OpenGL interop

This is my situation. My code calls to a function which contains a timing loop to do the simulation (monte-carlo simulation)

MyFUNC( …) {
//setting parameters

// timing loop (until the end of the simulation)
for (int i = 1; the_end; i++) {
//call CUDA kernel to do stuffs

 //CPU code to update parameters



During my simulation, it will update the data (temporal-spatial) that I want to visualize, i.e. (x, y, z, data) or (x, y, data), as a 3D surface. The sample CUDA-OpenGL codes that I have read, basically, need a small function, invoked by the callback and does a the computation to update to the data after a single-time step, i.e.

MyFUNC_1step(…) {

// call CUDA kernel to do stuffs

// CPU code to update parameters


void display() {



So, what I want is to keep my function MyFUNC as-is, and it will trigger the redisplayed by explicitly trigger something that tell the window to render (e.g. glutPostReDisplay()). This will allow me (1) keep running the simulation even after I close the window, (2) only update the display when I want (i.e. after a certain number of time steps of simulation). Do I have to use MPI to create one process to call the MyFUNC() and another process to call the main loop of GLUT (i.e. glutMainLoop)? or there is a better way. If I have to use MPI, how could I communicate with the window in a different process?
I’m not sure if my explanation is clear enough, please let me know.

Thank you,