Matlab's C API interface degrades over time

I've been having this issue (for years!), matlab slowing down gradually when running many iterations that use the C interface, which I've been handling by restarting matlab every X iterations:

https://au.mathworks.com/matlabcentral/answers/357286-how-to-completely-reset-matlab-s-workspace

Now, I'm having a similar issue, but restarting matlab doesn't help and isn't needed. I need to restart my own c++ app that uses matlab's C interface.

My estimate is that matlab's engine dll that my app is using degrades and doesn't reset between new engine connections.

Maybe somehow reloading the engine dlls may be enough?

[Jan]

I did not observe such a degradation. Of course, the C inrterface is not getting tired.

Can you provide a minimal working example to clarify, what the actual problem is? I'm even not sure what "degrading" means in detail. Do you mean leaking memory or creating zombie threads?

[Zohar]

Degrading ("matlab slowing down gradually") means that in the first 20 iterations, an iteration (that makes a few engine calls) takes 12sec to run. Over time, the running time increases, e.g., 1min per iteration after 2000 iterations.

From a first look, the executed matlab script itself takes the same time to run. By either calling the script or exchanging variables with the engine, it gets slower.

A minimal example would be tricky, but I'll give it some thought. Maybe I should start with the examples in the links on my linked thread.