Hello Cafe,
Here is a simple program that yields strange results:
module Main where
import Control.Concurrent
import Control.Concurrent.Chan
import Control.Monad
main = do
c - newChan
writeChan c 1
forkIO $ forever $ do
i - readChan c
print (forkio,i)
isEmptyChan c = print
First of
Shame on me, I forgot to include the software versions I use:
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 6.12.3
$ uname -a
Linux raptor 2.6.37-ARCH #1 SMP PREEMPT Sat Jan 29 20:00:33 CET 2011 x86_64
Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz GenuineIntel GNU/Linux
This
On 09/02/11 15:34, Krzysztof Skrzętnicki wrote:
Hello Cafe,
Here is a simple program that yields strange results:
module Main where
import Control.Concurrent
import Control.Concurrent.Chan
import Control.Monad
main = do
c - newChan
writeChan c 1
forkIO $ forever $ do
i - readChan c
You've been bitten by the following bug:
http://hackage.haskell.org/trac/ghc/ticket/4154
In short, isEmptyChan will block because of the concurrent call to readChan.
The solution is to not use isEmptyChan or switch to STM.
2011/2/9 Krzysztof Skrzętnicki gte...@gmail.com
Hello Cafe,
Here is
