[PATCH v6 1/2] ethdev: add query_update sync and async function calls

[Gregory Etelson]

Hello Andrew,

[]

> On 1/20/23 13:46, Gregory Etelson wrote:
> >>> and it's async version `rte_flow_async_action_handle_query_update`
> >>> to atomically query and update flow action.
> >>
> >> Sorry, may be I'm missing something, but after reading previous
> >> discussion I have a feeling that update could be queried data
> >> dependent. However, I don't understand how it could be possible
> >> with API below. Just my misunderstanding?
> >>
> >
> > The goal of `rte_flow_action_handle_query_update()` is to execute query
> and update actions atomically.
> > The function guaranties that action state will not change by any event
> before both update and query complete.
> > If the function was called with the ` RTE_FLOW_QU_QUERY_FIRST `
> `mode` argument, then update execution can depend
> > on query result. That's up to query format, PMD implementation and
> hardware capabilities.
> > I hope that answered your question.
> 
> Sorry, I'm still confused. Could you explain a bit more,
> please. How update could depend on query result?

Conditional update I described requires special action properties.
Consider an action object with a method that receives query and update as parameters.
The method will activate update only if query result satisfies action state.
If the action was updated, both query and update were atomic for application.
The function returns the action state - updated or not.
Application is aware about the action properties.
Application applies action properties to returned state to discover if action was updated.

> Caller already specified update structure...
 
Regards,
Gregory