Re: [Haskell-cafe] are forkIO threads event-driven?

Johan Tibell writes:

Hi Aran,

On Fri, Apr 30, 2010 at 9:28 PM, Aran Donohue wrote:

Thanks for the excellent links, that's exactly what I wanted. It's interesting that they've chosen not to base the new work on libevent. 

The reason was mostly performance concerns due to libev(ent) using callbacks to signal events. Callbacks from C into Haskell can be inefficient. From the FFI addendum:

Anecdotally, I can confirm this; we're using the FFI binding to libev in a project and for typical workloads it's actually a little slower than the plain-jane select()-based Haskell version. It scales better as you add connections of course. G -- Gregory Collins