Re: [dpdk-dev] [PATCH] ethdev: support action with any config object type

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 02.07.2019 12:57, Adrien Mazarguil wrote:
> On Tue, Jul 02, 2019 at 08:42:41AM +0000, Dekel Peled wrote:
>> Thanks, PSB.
>>
>>> -----Original Message-----
>>> From: Andrew Rybchenko <arybchenko@solarflare.com>
>>> Sent: Tuesday, July 2, 2019 11:09 AM
>>> To: Dekel Peled <dekelp@mellanox.com>; Adrien Mazarguil
>>> <adrien.mazarguil@6wind.com>; wenzhuo.lu@intel.com;
>>> jingjing.wu@intel.com; bernard.iremonger@intel.com; Yongseok Koh
>>> <yskoh@mellanox.com>; Shahaf Shuler <shahafs@mellanox.com>; Slava
>>> Ovsiienko <viacheslavo@mellanox.com>; arybchenko@solarflare.com
>>> Cc: dev@dpdk.org; Ori Kam <orika@mellanox.com>
>>> Subject: Re: [dpdk-dev] [PATCH] ethdev: support action with any config
>>> object type
>>>
>>> On 01.07.2019 17:10, Dekel Peled wrote:
>>>> In current implementation, an action which requires parameters must
>>>> accept them enclosed in a structure.
>>>> Some actions require a single, trivial type parameter, but it still
>>>> must be enclosed in a structure.
>>>> This obligation results in multiple, action-specific structures, each
>>>> containing a single trivial type parameter.
>>>>
>>>> This patch introduces a new approach, allowing an action configuration
>>>> object of any type, trivial or a structure.
>>>>
>>>> This patch introduces, in test-pmd, a new macro ARG_ENTRY_HTON, to
>>>> allow using a single argument, not enclosed in a structure.
>>>>
>>>> Signed-off-by: Dekel Peled <dekelp@mellanox.com>
>>> The term "object" confuses me a bit, but I'm not a native speaker so it could
>>> be just my wrong association. I'd prefer "configuration data".
>> In previous version I wrote just "action configuration", and changed to "action configuration object" per Adrien's suggestion. I think it is better, but if it causes confusion maybe it should be changed.
>>
>> Adrien, what do you think? Does "configuration data" carry the correct meaning?
> Well I'm no native speaker either but "object" is the term used in the C
> standard with a well-defined meaning [1] and encompasses everything
> (integers, floats, structures, unions, functions, pointers, arrays):
>
>   "region of data storage in the execution environment, the contents of which
>    can represent values"
>
> I think it's a bit less vague than "data" because whenever objects are
> mentioned in the standard, they always have a type. There's no such thing as
> a C object without one, and rte_flow puts a lot of emphasis on documenting
> them.
>
>   int foo;
>   struct { ... } foo;
>   double foo;
>   char foo[];
>   void *foo;
>   
> Whatever the type, would you refer to "foo" itself as an "object" or as
> "data"?

Adrien, thanks a lot. Now "object" looks OK and better than "data".

> Unrelated, but you must remove ARG_ENTRY_HTON from this patch since there's
> no testpmd change in there that requires it. There's no tolerance for dead
> code in testpmd as it doesn't expose an API.
>
> Thanks.
>
> [1] 3.14 "object"
>      http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf
>