Re: [tip:perf/core] events: Rename TRACE_EVENT_TEMPLATE() to DECLARE_EVENT_CLASS()

[Frederic Weisbecker <fweisbec@gmail.com>]

On Thu, Nov 26, 2009 at 02:44:27PM -0500, Steven Rostedt wrote:
> On Thu, 2009-11-26 at 20:20 +0100, Ingo Molnar wrote:
> > I think we generally want to encourage the creation of classes of 
> > events, not myriads of standalone events, each with their own call 
> > signature, record format and printouts.
> > 
> > In that sense making the TRACE_EVENT() one longer would achieve that 
> > goal of discouraging its over-use: DEFINE_SINGLE_EVENT() tells the 
> > developer that it's an event of it's kind.
> 
> But I do agree with Frederic that this can be a little confusing, since
> it makes it sound like DEFINE_EVENT is for multiple events.
> 
> What about saying exactly what it does?
> 
> DECLARE_AND_DEFINE_EVENT()


It tells so much that it is confusing :)

 
> 
> Come to think of it, since current TRACE_EVENT is now just:
> 
> #define TRACE_EVENT() \
> 	TRACE_EVENT_TEMPLATE() \
> 	DEFINE_EVENT
> 
> This may make the most sense. I haven't tried it, but I believe that you
> could even base other events off of the TRACE_EVENT. That is:
> 
> TRACE_EVENT(x, ...);
> 
> DEFINE_EVENT(x, y, ...);
> 
> And y would use x as its class.
> 
> So going back to your scheme of DECLARE_EVENT_CLASS(), it may make sense
> to have DECLARE_AND_DEFINE_EVENT().
> 
> 
> DECLARE_EVENT_CLASS(class, ...);
> DEFINE_EVENT(class, foo, ...);
> 
> DECLARE_AND_DEFINE_EVENT(bar, ...);



Yep, or DEFINE_EVENT_NOCLASS.



> DEFINE_EVENT(bar, zoo, ...);
> 
> 
> May work.
> 
> -- Steve
> 
>