Re: [Haskell-cafe] Need comments on a libusb asynchronous select/poll loop

20 Apr 2011


      On 20 April 2011 20:27, Bas van Dijk  wrote:
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On 20 April 2011 18:34, Johan Tibell  wrote:
...
On Wed, Apr 20, 2011 at 6:11 PM, Bas van Dijk  wrote:
...
I still need to add appropriate conditions for checking whether the
program is using the threaded RTS. What is the recommended approach
for this?
I see GHC.Conc.IO uses a dynamic check:
foreign import ccall unsafe "rtsSupportsBoundThreads" threaded :: Bool
Is this also available to me as a library author?
I think there's a ticket for adding something along the lines of
   getSystemEventManager :: IO (Maybe EventManager)
If that returns Just em, you're in the threaded RTS and have an EventManager.
Whoever is proposing[1] that is a real genius! ;-)
[1] http://thread.gmane.org/gmane.comp.lang.haskell.libraries/15458/focus=15543
Bas
I have now added the module System.USB.IO that automatically chooses
the asynchronous implementations when supported or the synchronous
otherwise:

https://github.com/basvandijk/usb/blob/async/System/USB/IO.hs

Bas