#14503: Killing a thread will block if there is another process reading from a
handle
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Reporter: dnadales | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: libraries/base | Version: 8.0.2
Resolution: | Keywords:
Operating System: Windows | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
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Comment (by bgamari):
Here is an complete all-Haskell repro,
{{{#!hs
-- Server.hs
import System.IO
import Network
import Control.Monad
import Control.Concurrent
main = withSocketsDo $ do
sock <- listenOn $ PortNumber 9090
(h, _, _) <- accept sock
forever $ do
threadDelay 100000
putStrLn "Trying to read something"
s <- hGetLine h
putStrLn $ "Got "++s
}}}
{{{#!hs
-- Client.hs
import Network
import System.IO
import Control.Concurrent
main = readWithinNSecs
readWithinNSecs :: IO ()
readWithinNSecs = withSocketsDo $ do
h <- connectTo "localhost" (PortNumber 9090)
hSetBuffering h NoBuffering
readerTid <- forkIO $ reader h
threadDelay $ 2 * 10^6
putStrLn "Killing the reader"
killThread readerTid
putStrLn "Reader thread killed"
where
reader h = do
line <- hGetLine h
putStrLn $ "Got " ++ line
}}}
Expected output (as seen on Debian 9 with GHC 8.2.2),
{{{
$ ghc Server.hs
$ ghc Client.hs
$ ./Server & ./Client
Trying to read something
Killing the reader
Reader thread killed
Server: