Is the memory used by MATLAB via calls through .NET independent of the .NET application?

Question

The reason I ask is that I have an application that (among other things) calls a MATLAB .NET component whenever data is written into a specific file. The component reads the file and creates an image out of the data contained within. This works fine.

However when I am using the underlying application to additionally process a "significant" amount of data and display the processed data in table, the call to MATLAB throws an out of memory exception, but only when I am processing this large amount of data.

Is this not an indication that the MATLAB process called will rely on the available memory of the application? I guess I just don't understand how the MATLAB memory works when being called from a .NET standpoint.

(I should also note that I call clear all before every call to the MATLAB function in an attempt to "start from scratch", but it fails regardless)

Answer 1

COM components built by Matlab Builder NE are in-process COM servers. This means that they are DLLs which are loaded into your application memory space. This means that the MCR, which is a kind of Matlab-Virtual-Machine is in your memory space.

I believe that .NET components should behave exactly the same.

Answer 2

It is entirely possible, and from what you've described, even likely that the MATLAB component is making use of unmanaged memory (memory that is not managed by the .NET garbage collector.) There is very little you can do about this, apart from ensuring that you only feed it expected data in expected quantities. You may also wish to create a support ticket with MATLAB, if you believe you are using it properly.

Answer 3

Never used MATLAB from C#, but as much I see it uses COM components to interact with the CLR world. You load the MATLAB unmanaged DLL's into your process memory heap. And considering that for CLR process on 32 bit machines you have approximately 1.2 GB memory space, so you go out of that available space.

Some interesting description of how the load of the unmanged COM component into the managed memory done, you can find here: Memory Management Of Unmanaged Component By CLR