Re: [boost] Re: Are signals order same across platforms?

From: Douglas Gregor (gregod_at_[hidden])
Date: 2003-04-24 16:57:33

On Thursday 24 April 2003 05:25 pm, Nicolas Fleury wrote:
> There's one advantage to the preprocessor option however.  Suppose you
> have an event-driven framework based on signals.  You might want the
> more optimized implementation, and therefore not condition-ordered, for
> most programs, but would like to make unit tests for this framework, and
> to ease their creation use the condition-ordered implementation.  It
> would however be an incomplete unit test since it would test only with a
> specific order. 

Given the subtle problems that can come from differences in slot ordering, I 
think this option may give one a false sense of security. It looks right in 
the unit test, but it's behavior is different in the real application. That 
spells trouble.

> If the performance is very similar for the
> connection-ordered solution, I guess this would not be an issue.  Do you
> have an idea what would be the cost in performance for
> connection-ordered signals?

I don't know the cost off-hand, but I think it isn't too high. Actually, using 
a list of slots and a mapping from group names to iterators into the list 
could actually improve performance in many common cases but would give 
order-of-connection slot ordering... I'll have to try that out.

> By the way, congratulations for your work on boost::signals and to all
> people involved.

Thank you.

        Doug