function TestEditorMemoryLeak(filepaths)
    for i = 1 : numel(filepaths)
        docobj = matlab.desktop.editor.openDocument(filepaths{i});
        disp([num2str(i), ': ', filepaths{i}]);
        pause(0.2);
        docobj.closeNoPrompt();
    end
end

Warning: do not run the above code with a large number of files. Depending on how much Java heap memory is allocated under matlab general settings, it could cause matlab to crash and hang causing loss of command history and matlab settings.

I used the above code on about 1300 files, where each file was not too large – maybe an average of around 50 lines per file. On my system, which has the default 768 MB of Java heap memory allocated, the memory runs out after about a thousand files and matlab (2020a) hangs, badly.

I thought that Java garbage collection might clean up after the function runs, but the 768 MB of memory remains used and never goes back to normal in the Windows task manager.

Increasing the Java heap memory setting appropriately, resolves the issue, but I would like to find a real solution.

@Stefan – MAT files do not contain history (except if you designed them to contain it), so yyour only option is to check if this file was backed up.

@Bobby – the test script above should be fairly easy for you to run on your specific system to check this. And as noted, you can always use the java.io.File(tn).delete() workaround.

If so, if I want to override these files for a project, how do I avoid shadow warnings if I wish to keep the files named the same and on my path? Thanks

exist(name,'file')

In the Matlab call of exist, they are caching the result as to make subsequent calls fast, but if you do large numbers of “exist” calls on files with different names (e.g. with constantly increasing index values in the file name), each one of those results is permanently cached. The result is a constant memory “leak” (well, technically memory is being put to good use, so not a leak in that sense, but there apparently no way to clear that cache and recover the memory). However, using:

file.io.File(name).isFile

works like a charm… AS LONG AS you don’t have the need to search the entire Matlab path. That is the ONE thing the Java call won’t do that the exist() call does.

@Jan – thanks, sharp eyes! (now corrected)