matlab - Break out of proprietary toolbox after a given time

Question

I am iterating through a large test matrix in MATLAB and calling second-party proprietary software (running in MATLAB) each time. I cannot edit the software source code. Sometimes, the software hangs, so I want to exit it after a certain amount of time and move on to the next iteration.

In pseudocode, I'm doing this:

for i = 1:n
    output(i) = proprietary_software(input(i));
end

How can I skip to the next iteration (and possibly save output(i)='too_long') if the proprietary software is taking too long?

Answer 1

You will need to call Matlab from another instance of Matlab. The other instance of Matlab will run the command and release control to the first instance of Matlab to wait while it either saves the results or reaches a certain time. In this case, it will wait 30 seconds.

You will need 1 additional function. Make sure this function is on the Matlab path.

function proprietary_software_caller(input)
    hTic=tic;
    output=proprietary_software(input);
    hToc=toc(hTic);
    if hToc<30
       save('outfile.mat','output');
    end
    exit;
end

You will need to modify your original script this way

[status,firstPID] = str2double(system('for /f "tokens=2 delims=," %F in (''tasklist /nh /fi "imagename eq Matlab.exe" /fo csv) do @echo %~F'')'));

for i = 1:n
    inputStr=num2str(input(i));
    system(['matlab.exe -nodesktop -r proprietary_software_caller(',inputStr,')&']);
    hTic=tic;
    hToc=toc(hTic);
    while hToc<30 || ~(exist('outfile.mat','file')==2)
       hToc=toc(hTic);
    end
    if hToc>=30
        output(i)= 'too_long';
        [status,allPIDs]=str2double(system('for /f "tokens=2 delims=," %F in (''tasklist /nh /fi "imagename eq Matlab.exe" /fo csv) do @echo %~F'')'));
        allPIDs(allPIDs==firstPID)=[];
        for a=1:numel(allPIDs)
           [status,cmdout]=system(['taskkill /F /pid ' sprintf('%i',allPIDs(a))]);
        end
    elseif exist('outfile.mat','file')==2
        loadedData=load('outfile.mat');
        output(i)=loadedData.output;
        delete('outfile.mat');
    end
end

I hope this helps.