One-shot semantics in GHC event manager

[Austin Seipp]

The catch with such a change is that there is no macro to determine
whether we're using 7.8.3 or 7.8.4, so it's harder for users to figure
things out (they have to use `MIN_VERSION_base` from Cabal). But maybe
that doesn'tm atter too much. So, yes, I think it's doable, but that's
a sticky bit.

Andreas - want me to go ahead and get you some hardware to test Ben's
patch in the mean time? This way we'll at least not leave it hanging
until the last moment...

On Fri, Oct 17, 2014 at 7:59 AM, Andreas Voellmy
<andreas.voellmy at gmail.com> wrote:
> I haven't had a chance to dig into Ben's patch yet, but I expect it will
> accepted soon - I don't think the change will affect performance.
>
> Austin, would it be possible to get a relatively minor change to the event
> manager into 7.8.4? It may change a semi-public API under GHC.Event, but
> will not change any public API. What is our time window?
>
> Andi
>
> On Fri, Oct 17, 2014 at 8:34 AM, Bas van Dijk <v.dijk.bas at gmail.com> wrote:
>>
>> Hi Ben, Austin,
>>
>> Is there any chance of Ben's event manager patch landing in GHC-7.8.4?
>>
>> Bas
>>
>> On 13 October 2014 21:05, Ben Gamari <bgamari.foss at gmail.com> wrote:
>> > Ben Gamari <bgamari.foss at gmail.com> writes:
>> >
>> >> Andreas Voellmy <andreas.voellmy at gmail.com> writes:
>> >>
>> >>> On Sat, Oct 11, 2014 at 12:17 PM, Ben Gamari <bgamari.foss at gmail.com>
>> >>> wrote:
>> >>>
>> >>> Ah... so this is not useful to you. I guess we could add `loop` to
>> >>> GHC.Event's export list. On the other hand, I like your LifeTime
>> >>> proposal
>> >>> better and then no one needs `loop`, so let's try this first.
>> >>>
>> >> I have a first cut of this here [1]. It compiles but would be I shocked
>> >> if it ran. All of the pieces are there but I need to change
>> >> EventLifetime to a more efficient encoding (there's no reason why it
>> >> needs to be more than an Int).
>> >>
>> > As it turns out the patch seems to get through the testsuite after a few
>> > minor fixes.
>> >
>> > What other tests can I subject this to? I'm afraid I don't have the
>> > access to any machine even close to the size of those that the original
>> > event manager was tested on so checking for performance regressions will
>> > be difficult.
>> >
>> > Cheers,
>> >
>> > - Ben
>> >
>> > _______________________________________________
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>> > ghc-devs at haskell.org
>> > http://www.haskell.org/mailman/listinfo/ghc-devs
>> >
>
>



-- 
Regards,

Austin Seipp, Haskell Consultant
Well-Typed LLP, http://www.well-typed.com/