[Haskell-cafe] Faster timeout but is it correct?

[Bas van Dijk]

On 18 February 2011 01:05, Johan Tibell <johan.tibell at gmail.com> wrote:
> On Thu, Feb 17, 2011 at 5:01 PM, Bas van Dijk <v.dijk.bas at gmail.com> wrote:
>> willTimeout/old         24.34945 us    1.0 x
>> willTimeout/new         26.91964 us    0.9 x (large std dev: 5 us)
>> willTimeout/event       12.94273 us    1.9 x  :-)
>>
>> wontTimeout/old         16.25766 us    1.0 x
>> wontTimeout/new         637.8685 ns   25.5 x  :-)
>> wontTimeout/event       1.565311 us   10.4 x  :-)
>
> I find this very surprising. Both new and event eventually ends up
> using the event manager in the end. One via threadDelay (which calls
> registerTimeout) and one directly via registerTimeout. The difference
> should be that "new" also spawns a thread.

I guess the new timeout exploits parallelism because it forks a thread
do to the work with the event manager. I think that this thread is
then killed before it even begins dealing (through threadDelay) with
the event manager.

Bas