On 20 May 2016 at 03:14, Savolainen, Petri (Nokia - FI/Espoo) <petri.savolai...@nokia.com> wrote: > > > From: Bill Fischofer [mailto:bill.fischo...@linaro.org] > Sent: Friday, May 20, 2016 2:58 AM > To: Savolainen, Petri (Nokia - FI/Espoo) <petri.savolai...@nokia.com> > Cc: Christophe Milard <christophe.mil...@linaro.org>; LNG ODP Mailman List > <lng-odp@lists.linaro.org> > Subject: Re: [lng-odp] [PATCH 1/2] doc: userguide: add section describing > helpers > > > > On Thu, May 19, 2016 at 3:09 AM, Savolainen, Petri (Nokia - FI/Espoo) > <petri.savolai...@nokia.com<mailto:petri.savolai...@nokia.com>> wrote: > > >> -----Original Message----- >> From: lng-odp >> [mailto:lng-odp-boun...@lists.linaro.org<mailto:lng-odp-boun...@lists.linaro.org>] >> On Behalf Of >> Christophe Milard >> Sent: Thursday, May 19, 2016 10:43 AM >> To: Bill Fischofer >> <bill.fischo...@linaro.org<mailto:bill.fischo...@linaro.org>> >> Cc: LNG ODP Mailman List >> <lng-odp@lists.linaro.org<mailto:lng-odp@lists.linaro.org>> >> Subject: Re: [lng-odp] [PATCH 1/2] doc: userguide: add section describing >> helpers >> >> On 19 May 2016 at 06:05, Bill Fischofer >> <bill.fischo...@linaro.org<mailto:bill.fischo...@linaro.org>> wrote: >> >> > Signed-off-by: Bill Fischofer >> > <bill.fischo...@linaro.org<mailto:bill.fischo...@linaro.org>> > > >> > >> > +=== ODP Helpers >> > +ODP also provides a set of _helper_ functions that are >> > +distinguished by the `odph_` prefix. These are not part of the ODP API >> > +specification, but may be useful to both applications and >> implementations. >> > >> >> This statement allows for circular dependancy: >> Using helpers from the application means that helpers will use ODP, as >> helpers will perform usual stuff that application needs to do: for >> instance >> helpers uses the ODP cpu_mask for creating threads, and helpers may do >> other common application things toward ODP according to this definition. >> Having things such as IP header description in helpers means that helpers >> are needed by ODP: >> In other words: helper is needed by ODP and needs ODP! >> I know this is the situation today, but I am not sure we should write this >> in stone. Maybe the helpers should be splitted as ODP_helpers and >> APP_helpers? > > I don't see the need to make this distinction. While it is true that some > helpers use ODP APIs that's perfectly fine since ODP implementations are free > to use ODP APIs themselves, and we do that a lot to simplify the code in many > places. To have a true circular reference would be to have an unresolvable > recursive reference, which is not the case here. > >> > > Helpers are for applications (reuse code and definitions in examples and > tests). Implementations should contain their own (protocol header) > definitions, so no dependency to the helper lib. > > The reason we put the header mappings in the helpers in the first place is to > avoid this sort of unnecessary duplication, so this statement seems odd. > There is, of course, no requirement that implementations use these or any > other helper functions. They are simply there as a matter of application > and/or implementation convenience. > > > Since this is user documentation, it does not need to speculate how > implementation might have been constructed.
This is an old thread but odp-linux cannot depend on odp helpers, you can't package aloop cleanly I am told, so I dont know if that needs documenting From user point of view all odph_ definitions are there for test/example/other app convenience. agree, they are not for the implementations, at least we need to split them if there are to be helpers for both, implementation helpers and app helpers. Each implementation decides independently how and where it defines e.g. protocol headers (include those from SDK or some other library, define from scratch, include odp helpers, …). disagree, no implementation should depend on helpers, it breaks packaging. Any implementation that does this is not going to work well with distributions. It may get them from an SDK, but then the dependency remains one way > > -Petri > > > > _______________________________________________ > lng-odp mailing list > lng-odp@lists.linaro.org > https://lists.linaro.org/mailman/listinfo/lng-odp -- Mike Holmes Technical Manager - Linaro Networking Group Linaro.org │ Open source software for ARM SoCs "Work should be fun and collaborative, the rest follows" _______________________________________________ lng-odp mailing list lng-odp@lists.linaro.org https://lists.linaro.org/mailman/listinfo/lng-odp
