a2754c7 · distributed-process

git.iko.soy/distributed-process

Fix a bug in the built-in log file tracer

Using `matchAnyIf` we managed to fool the type checker into passing a Message instance into a predicate pattern matching on TraceEvent.

commita2754c7fa76f14cc91ad7fd75d4b910ce14e4195 authorTim Watson <tim@rabbitmq.com> dateWed 24 Apr 2013, 12:05 (13 years ago) parentac17228

1 file changed+8−6

unifiedsplit

src/Control/Distributed/Process/Internal/Trace/Tracer.hs+8−6

@@ -20,6 +20,7 @@ import Control.Distributed.Process.Internal.CQueue

2020 )

2121import Control.Distributed.Process.Internal.Primitives

2222 ( catch

23+ , finally

2324 , die

2425 , receiveWait

2526 , forward

@@ -27,6 +28,7 @@ import Control.Distributed.Process.Internal.Primitives

2728 , match

2829 , matchAny

2930 , matchAnyIf

31+ , matchIf

3032 , handleMessage

3133 , matchUnknown

3234 , whereis

@@ -163,16 +165,16 @@ logfileTracer p = do

163165 liftIO $ putStrLn $ "writing to " ++ (show p)

164166 h <- liftIO $ openFile p AppendMode

165167 liftIO $ hSetBuffering h LineBuffering

166− logger h `catch` (\(_ :: SomeException) -> liftIO $ hClose h)

168+ logger h `finally` (liftIO $ hClose h)

167169 where

168170 logger :: Handle -> Process ()

169171 logger h' = forever' $ do

170172 receiveWait [

171− matchAnyIf (\ev -> case ev of

172− TraceEvDisable -> True

173− (TraceEvTakeover _) -> True

174− _ -> False)

175− (\_ -> (liftIO $ hClose h') >> die "trace stopped")

173+ matchIf (\ev -> case ev of

174+ TraceEvDisable -> True

175+ (TraceEvTakeover _) -> True

176+ _ -> False)

177+ (\_ -> (liftIO $ hClose h') >> die "trace stopped")

176178 , matchAny (\ev -> handleMessage ev (writeTrace h'))

177179 ]

178180