id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
4802	'current directory' is not thread local	tanakh	simonmar	"In a threaded code, the current directory is not thread local, even using forkOS.

For example:

{{{
import System.Directory
import Control.Concurrent

main :: IO ()
main = do
  print =<< getCurrentDirectory

  forkOS $ do
    setCurrentDirectory ""a""
    threadDelay $ 10^6
    print =<< getCurrentDirectory

  forkOS $ do
    threadDelay $ 10^6
    print =<< getCurrentDirectory

  threadDelay $ 20*10^6
}}}

The output is:

{{{
$ ghc --make -threaded curdir.hs
[1 of 1] Compiling Main             ( curdir.hs, curdir.o )
Linking curdir ...
$ ./curdir 
""/home/hideyuki""
""/home/hideyuki/a""
""/home/hideyuki/a""
}}}

It seems to inherit the specification of pthread. It may be environment-dependent behavior (At least, on Linux and Windows, same results are given).

If the behavior like above is the specific, documents should be added to setCurrentDirectory/getCurrentDirectory. It is very confusing.

Or if it is possible to wrap the behabior of 'current directory' to make thread local in Haskell code, I hope to make it so.
"	bug	closed	normal	7.2.1	libraries/directory	7.0.1	fixed		tanaka.hideyuki@…	Unknown/Multiple	Unknown/Multiple	Documentation bug