Multiprocessing on windows throws RuntimeError

[vidicunt]

Attempting to use multiprocessing on Windows throws a RuntimeError.

Compared to running the Python code, where the master process has __name__ = '__main__' and slave processes are '__mp_main__', the compiled Cython code only initialises 'main' processes.

RuntimeError:
        An attempt has been made to start a new process before the
        current process has finished its bootstrapping phase.

        This probably means that you are not using fork to start your
        child processes and you have forgotten to use the proper idiom
        in the main module:

            if __name__ == '__main__':
                freeze_support()
                ...

        The "freeze_support()" line can be omitted if the program
        is not going to be frozen to produce an executable.

I did use:

if __name__ == '__main__' or __name__ == "main":
    code()

[scoder]

Duplicate of #3262.