On Wed, 2009-12-02 at 13:06 -0500, Mathieu Desnoyers wrote: > * > Hrm. I wonder if having DEFINE_EVENT_CLASS is really worth having, > considering that it really just does 2 things at once and may be > confusing. We keep it because that's what TRACE_EVENT currently is. It would suck to have to replace every TRACE_EVENT there is now with a DECLARE_EVENT_CLASS and DEFINE_EVENT. Although this would push developers into using classes. > > I would have thought amongst the lines of the following as main API > (note: "SKETCH" is only a proposal. The idea is to do _not_ use > declare/define, as it's really something _different_ than what people > are expecting!) > > SKETCH_EVENT_CLASS() > > SKETCH_EVENT() > > Which would use only DECLARE, or both DECLARE and DEFINE depending if > CREATE_TRACE_POINTS is set. I see the DECLARE/DEFINE more as the > "low-level" macros that are actually selected by CREATE_TRACE_POINTS: > > DECLARE_EVENT_CLASS : only performs event class declarations (macros, > inlines...) > > DECLARE_EVENT : only performs event instance declarations (macros, > inlines, ...). Depends on the DECLARE_EVENT_CLASS(). > > DEFINE_EVENT_CLASS : create instances of template functions. > > DEFINE_EVENT : create event tracepoint functions. Depends on > DEFINE_EVENT_CLASS(). > > This way, it should make digging into the generation system internals > headhache-free. ;) I think we should really avoid re-using terms people > are familiar with for things that have a semantic intrincially different > than what people come to expect. Egad No! It would make it a living nightmare. The internals reuse the define macro, and there's no intermediate. By changing the DECLARE_EVENT_CLASS to another name (SKETCH_EVENT_CLASS) we would have to add something like this: #define SKETCH_EVENT_CLASS(name, proto, args, tstruct, print) \ DECLARE_EVENT_CLASS(name, PARAMS(proto), PARAMS(args),\ PARAMS(tstruct), PARAMS(print)) We don't have a intermediate or "low level" macro in use here. Whatever we give to the user is what we use. I think the kernel developers are smart enough to figure out that these macros are not a typical DECLARE/DEFINE that is elsewhere. But I think using the DECLARE/DEFINE names will give them a better idea of what is happening than to make up something completely new. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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