diff options
| -rw-r--r-- | compiler/main/Finder.lhs | 20 | ||||
| -rw-r--r-- | compiler/main/GHC.hs | 7 |
2 files changed, 18 insertions, 9 deletions
diff --git a/compiler/main/Finder.lhs b/compiler/main/Finder.lhs index 21d7febd44..17299fb194 100644 --- a/compiler/main/Finder.lhs +++ b/compiler/main/Finder.lhs @@ -37,10 +37,11 @@ import Outputable import FiniteMap import LazyUniqFM import Maybes ( expectJust ) +import Exception ( evaluate ) import Distribution.Text import Distribution.Package hiding (PackageId) -import Data.IORef ( IORef, writeIORef, readIORef, modifyIORef ) +import Data.IORef ( IORef, writeIORef, readIORef, atomicModifyIORef ) import System.Directory import System.FilePath import Control.Monad @@ -67,6 +68,7 @@ type BaseName = String -- Basename of file -- assumed to not move around during a session. flushFinderCaches :: HscEnv -> IO () flushFinderCaches hsc_env = do + -- Ideally the update to both caches be a single atomic operation. writeIORef fc_ref emptyUFM flushModLocationCache this_pkg mlc_ref where @@ -76,23 +78,27 @@ flushFinderCaches hsc_env = do flushModLocationCache :: PackageId -> IORef ModLocationCache -> IO () flushModLocationCache this_pkg ref = do - fm <- readIORef ref - writeIORef ref $! filterFM is_ext fm + atomicModifyIORef ref $ \fm -> (filterFM is_ext fm, ()) + _ <- evaluate =<< readIORef ref return () where is_ext mod _ | modulePackageId mod /= this_pkg = True | otherwise = False addToFinderCache :: IORef FinderCache -> ModuleName -> FindResult -> IO () -addToFinderCache ref key val = modifyIORef ref $ \c -> addToUFM c key val +addToFinderCache ref key val = + atomicModifyIORef ref $ \c -> (addToUFM c key val, ()) addToModLocationCache :: IORef ModLocationCache -> Module -> ModLocation -> IO () -addToModLocationCache ref key val = modifyIORef ref $ \c -> addToFM c key val +addToModLocationCache ref key val = + atomicModifyIORef ref $ \c -> (addToFM c key val, ()) removeFromFinderCache :: IORef FinderCache -> ModuleName -> IO () -removeFromFinderCache ref key = modifyIORef ref $ \c -> delFromUFM c key +removeFromFinderCache ref key = + atomicModifyIORef ref $ \c -> (delFromUFM c key, ()) removeFromModLocationCache :: IORef ModLocationCache -> Module -> IO () -removeFromModLocationCache ref key = modifyIORef ref $ \c -> delFromFM c key +removeFromModLocationCache ref key = + atomicModifyIORef ref $ \c -> (delFromFM c key, ()) lookupFinderCache :: IORef FinderCache -> ModuleName -> IO (Maybe FindResult) lookupFinderCache ref key = do diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs index aef6b9bb0b..9e2b3068e6 100644 --- a/compiler/main/GHC.hs +++ b/compiler/main/GHC.hs @@ -2342,8 +2342,11 @@ cyclicModuleErr ms -- | Inform GHC that the working directory has changed. GHC will flush -- its cache of module locations, since it may no longer be valid. --- Note: if you change the working directory, you should also unload --- the current program (set targets to empty, followed by load). +-- +-- Note: Before changing the working directory make sure all threads running +-- in the same session have stopped. If you change the working directory, +-- you should also unload the current program (set targets to empty, +-- followed by load). workingDirectoryChanged :: GhcMonad m => m () workingDirectoryChanged = withSession $ (liftIO . flushFinderCaches) |