Re: scalable event scheduling

On 31/01/2013 6:44 p.m., Alex Rousskov wrote:
> On 01/30/2013 06:30 PM, Amos Jeffries wrote:
>
>> I've kind of gone off the idea of leaving old code using a wrapper API
>> with the old behaviour. All that we have got out of that approach is
>> added technical debt for others whoc have to ome along afterwards and
>> learn two API interfaces then decide which ne to remove
> I agree that adding a conflicting API is bad, so I would like to add a
> fourth step to my sketch:
>
> 4. Upgrade all users of eventDelete(f,a) API that currently supply a
> non-NULL second argument to use new eventDelete() that supplies an async
> call (from step #1). If possible, convert all other eventDelete users to
> the new eventDelete(). If not possible, rename the old two-argument
> eventDelete(f,NULL) to a single-argument eventDeleteAll(f) call.
>
> This fourth step will eliminate or, in the worst case, minimize doubts
> and conflicts for future API users.
>
>
>> It is far better, easier, simpler, safer to have the one person who
>> understands the change properly, replace all the existing API fuctions
>> in one polish patch. This will also teach them if there is some weird
>> caller hidden somewhere that breaks under the new design. AND, will
>> assist with portage by causing build errors when the API from newer code
>> is not converted to the older versions required API.
> Agreed. Unfortunately, it is often the case that the "one person who
> understands the change properly" is nowhere to be found, too busy, is
> viewed as disrupting attempts to fix something by others, and/or
> multiple people think they understand the change properly, but their
> understanding differs :-).

Interesting definition of "one" you have there.

I was speaking about the time of initial API change. The points you
highlight as issues down the track are all caused by broken or inomplete
API transitions, which a lot of the time are caused directly by doing
the transition with wrappers.

Amos
Received on Thu Jan 31 2013 - 06:10:07 MST