Re: Tell whether a primitive subprogram was overridden

[Victor Porton <porton@narod.ru>]

Dmitry A. Kazakov wrote:

> On Tue, 19 Aug 2014 16:45:54 +0300, Victor Porton wrote:
> 
>> Dmitry A. Kazakov wrote:
> 
>>> You mean that a check would be more efficient than a dispatching call? I
>>> don't think there would be much difference, except the case when the
>>> subprogram has a long list of additional arguments or computed
>>> arguments. That is usually the case when doing tracing stuff. In that
>>> case you could think of some lazy parameter evaluation schema or upfront
>>> checks as Adam suggested.
>> 
>> No. I haven't described exactly what I do.
>> 
>> I need to register (by calling a C function) a C wrapper around a method
>> of my class as a callback subprogram. If my method is null, it is not
>> necessary to register it and the C code would not call it.
> 
> You certainly register it only once. Therefore it is indeed the overhead
> of a single dispatching call = a couple of nanoseconds. If you are in this
> area you should look at C code as well. It checks if something is
> registered. The depending on the choice it does a jump or no jump. Jump is
> also a nanosecond of so.

No, I register it either once or zero times.

If it is not registered, the program is a little faster.

-- 
Victor Porton - http://portonvictor.org