'current directory' is not thread local
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.
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/directory |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |