any problem if do two same analyses (e.g. ALFF) with two separate Matlab at the same time in the same user account?

Hi, when I do two same analyses (e.g. ALFF) with two separate Matlab at the same time in the same user account, I found that it is likely that one of the analysis crashes with the other. I notice that they both produce and erase tmp files with random numbers in the /tmp/ directory constantly. If both analyses produced the same file concidently, e.g. ALFF_3462_username, and one of the analysis deleted it after using it while the other analysis suddenly lose track of such file then it will crash. Is that true?

Now even if one of the analysis seems to finish ALFF first (i.e. it didn't crash), is it possible that such ALFF computation may not be 100% correct due to the interference of the other analysis?

Thanks for your answer!