Can a system() Command be used Inside a Function Called from Inside a parfor Loop?

Is the following code allowed:

result = zeros(100,1);
parfor ii = 1:100
   
    % do something
    result(ii) = myfun(resultfromdoingsomething)

end

function result = myfun(inp)
    % do something and write a file based on inp
    status = system(command);  % command executes an executable that reads in the file that was written and produces an output file
    result = % read in the file produced by the executable and grab a value to return
    % delete the files
end

Even if allowed, are there any risks to be concerned about?

Would also like to know if there are any differences between 2024a and 2019b in this regard.

Answer 1

[Epsilon]

Hi Paul,

A 'system' command inside a function called from within ‘parfor’ seems to be working fine.

Code:

function myFunction(index) 
command = sprintf('echo Processing index %d', index); 
[~, cmdout] = system(command); 
disp(['Output for index ', num2str(index), ': ', cmdout]); 
end 

parfor i = 1:100
    myFunction(i); 
end 

Output for index 100: Processing index 100

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One of the issues can be when multiple iterations try to access shared resources and can create conflicts.

Both the ‘parfor’ and ‘system’ are supported by the releases R2024a and R2019b so it should work fine.

Links to the Documentations:

parfor(R2019b): https://www.mathworks.com/help/releases/R2019b/parallel-computing/parfor.html

parfor(R2024a): https://www.mathworks.com/help/parallel-computing/parfor.html

system(R2019b): https://www.mathworks.com/help/releases/R2019b/matlab/ref/system.html

system(R2024a): https://www.mathworks.com/help/matlab/ref/system.html