Re: Handling multiple fds with GHC

On Wed, Oct 7, 2015 at 10:16 AM, Markus Ongyerth wrote:

Mostly because i am used to the poll/select method I mentioned and that one works without any threading. I don't really mind using the threaded runtime though, it's more habit.

The stock stuff in the threaded runtime uses epoll() out of the box. When you call hRead on a Handle, if the handle would block then you ultimately get a call to threadWaitRead https://hackage.haskell.org/package/base-4.8.1.0/docs/GHC-Conc.html#v:thread... or threadWaitWrite; these functions register interest in the given file descriptor, and the IO manager / GHC runtime scheduler will wake up your thread (GHC uses "green" threads) when the file descriptor becomes writable. G -- Gregory Collins