[lttng-dev] TP_ARGS for TRACEPOINT_EVENT_CLASS and TRACEPOINT_EVENT_INSTANCE

[Yonghong Yan]

Then why bother to require to have the TP_ARGS in
TRACEPOINT_EVENT_INSTANCE?

Yonghong

On Thu, Dec 20, 2018 at 11:56 AM Philippe Proulx <eeppeliteloop at gmail.com>
wrote:

> On Thu, Dec 20, 2018 at 11:47 AM Yonghong Yan <yanyh15 at gmail.com> wrote:
> >
> > I am looking at the following example from lttng-ust manual. The same
> TP_ARGS ( ... ) are repeated in both the TRACEPOINT_EVENT_CLASS and
> TRACEPOINT_EVENT_INSTANCE definition. My understanding is that it actually
> allows using different arguments, even in this example it is the same. Am I
> right?
>
> No it does not: they need to match.
>
> See <
> https://github.com/lttng/lttng-ust/commit/c75c0422c64f33c0102e1778cecc812c58b700e5
> >.
>
> Phil
>
> >
> > I also like the feature of having one TP_ARGS in the
> TRACEPOINT_EVENT_CLASS that declares the arguments for several
> TRACEPOINT_EVENT_INSTANCE so we do not need to have TP_ARGS in
> TRACEPOINT_EVENT_INSTANCE. Is that possible?
> >
> > Thank you
> > Yonghong
> >
> > TRACEPOINT_EVENT_CLASS(
> >     my_provider,
> >     my_tracepoint_class,
> >     TP_ARGS(
> >         int, my_integer_arg,
> >         struct app_struct *, app_struct_arg
> >     ),
> >     TP_FIELDS(
> >         ctf_integer(int, a, my_integer_arg)
> >         ctf_integer(unsigned long, b, app_struct_arg->b)
> >         ctf_string(c, app_struct_arg->c)
> >     )
> > )
> >
> > TRACEPOINT_EVENT_INSTANCE(
> >     my_provider,
> >     my_tracepoint_class,
> >     event_instance1,
> >     TP_ARGS(
> >         int, my_integer_arg,
> >         struct app_struct *, app_struct_arg
> >     )
> > )
> >
> > TRACEPOINT_EVENT_INSTANCE(
> >     my_provider,
> >     my_tracepoint_class,
> >     event_instance2,
> >     TP_ARGS(
> >         int, my_integer_arg,
> >         struct app_struct *, app_struct_arg
> >     )
> > )
> >
> >
> > _______________________________________________
> > lttng-dev mailing list
> > lttng-dev at lists.lttng.org
> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>
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