If an error condition occurs, this routine returns an integer
    value indicating the type of error, the mutex is not initialized,
    and the contents of mutex are undefined. Possible return values
    are as follows:

    Return      Description

    0           Successful completion.
    [EAGAIN]    The system lacks the necessary resources to
                initialize the mutex.
    [EBUSY]     The implementation has detected an attempt to
                reinitialize the mutex (a previously initialized,
                but not yet destroyed mutex).
    [EINVAL]    The value specified by mutex is not a valid mutex.
    [ENOMEM]    Insufficient memory exists to initialize the mutex.
    [EPERM]     The caller does not have privileges to perform this
                operation.