Possible error using concurrency
{-
Error description:
In windows xp sp2 with ghc-6-4, GHCi ends with
"internal error: deadlock: main thread blocked in a
strange way"
In RedHat Linux, it just blocks.
A probably cause, it's that the scheduler hasn't yet
run oneThread
before the second putTMVAr, because no memory
allocation has been
requested.
Try on the calls forkIO and runInUnboundThread.
contact info: leonelfl@yahoo.com
-}
import Control.Concurrent
import Control.Concurrent.STM
import Control.Concurrent.STM.TMVar
main = do
stopFlag <- atomically (do t <- newEmptyTMVar;
return t)
threadDelay 100001
--t <- forkIO $ oneThread stopFlag -- this line would
work fine...
-- but the following one doesn't work.
runInUnboundThread $ oneThread stopFlag
threadDelay 100002
atomically ( putTMVar stopFlag True )
threadDelay 500003
atomically ( putTMVar stopFlag False )
return ()
oneThread stopFlag = do
go <- atomically ( takeTMVar stopFlag )
if go then do putStrLn "-"
oneThread stopFlag
else return ()
Trac metadata
Trac field |
Value |
Version |
6.4 |
Type |
Bug |
TypeOfFailure |
OtherFailure |
Priority |
normal |
Resolution |
ResolvedFixed |
Component |
libraries (other) |
Test case |
|
Differential revisions |
|
BlockedBy |
|
Related |
|
Blocking |
|
CC |
|
Operating system |
|
Architecture |
|