def timed_do_fn(f):
    """Decorate a do function to log before, after, and elapsed time,
    with the name of the calling function.  This is not speedy!"""
    def wrap(callable, *args, **kwargs):
        global _debug_id

        # get a description of the function that called us
        st = traceback.extract_stack(limit=2)
        file, line, name, _ = st[0]

        # and its locals
        frame = inspect.currentframe()
        locals = frame.f_locals

        # invent a unique ID for the description
        id, _debug_id = _debug_id, _debug_id + 1

        descr = "%s-%08x" % (name, id)

        start_time = time.time()
        log.msg("%s - before ('%s' line %d)" % (descr, file, line))
        for name in locals:
            if name in ('self', 'thd'):
                continue
            log.msg("%s -   %s = %r" % (descr, name, locals[name]))

        # wrap the callable to log the begin and end of the actual thread
        # function
        def callable_wrap(*args, **kargs):
            log.msg("%s - thd start" % (descr,))
            try:
                return callable(*args, **kwargs)
            finally:
                log.msg("%s - thd end" % (descr,))
        d = f(callable_wrap, *args, **kwargs)

        @d.addBoth
        def after(x):
            end_time = time.time()
            elapsed = (end_time - start_time) * 1000
            log.msg("%s - after (%0.2f ms elapsed)" % (descr, elapsed))
            return x
        return d
    wrap.__name__ = f.__name__
    wrap.__doc__ = f.__doc__
    return wrap
Decorate a do function to log before, after, and elapsed time,
    with the name of the calling function.  This is not speedy!