[Haskell-cafe] How to ensure code executes in the context of a specific OS thread?

[Jason Dagit]

On Sun, Jul 3, 2011 at 10:22 PM, Felipe Almeida Lessa
<felipe.lessa at gmail.com> wrote:
> On Mon, Jul 4, 2011 at 2:02 AM, Jason Dagit <dagitj at gmail.com> wrote:
>> My second question is, if there is no current workaround then how can
>> we remedy this situation?  It seems like there could be an api
>> function like:
>> runOnOriginalThread :: IO a -> IO a
>
> Isn't there something on Cocoa that would allow you to implement this
> function?  For example, to implement postGUISync [1] on Gtk2Hs, Glib's
> g_idle_add() [2] is used [3].  To implement Gtk.Application.Invoke [4]
> on Gtk#, Glib's g_timeout_add with a timeout of 0 seconds is used [6].
>  In other words, some way of running an arbitrary function inside
> Cocoa's event loop.

There are a few objective-c specific ways of sending something to the
right thread.  I was hoping to find something a bit more general and
easier to call from Haskell (I believe the way the FFI works I'll have
to make a new wrapper for each "thing" because I can't directly call
objective-c).

I suppose I should try adding wrappers around all the GLFW functions
so that it sends the request over to the main thread and see if it
solves my problem.  The downside is that it would be a lot of wrapper
code and it would be nice to have solution that other libraries can
use.

Thanks for the idea.

Jason