Make access to NameCache atomic. Sometimes needs a lock.

[ghc-hetmet.git] / compiler / main / HscTypes.lhs

diff --git a/compiler/main/HscTypes.lhs b/compiler/main/HscTypes.lhs
index 05c17ab..962c7a3 100644 (file)
--- a/compiler/main/HscTypes.lhs
+++ b/compiler/main/HscTypes.lhs
@@ -164,6 +164,7 @@ import Data.Array       ( Array, array )
 import Data.List
 import Control.Monad    ( mplus, guard, liftM, when )
 import Exception
+import Control.Concurrent.MVar ( MVar )
 \end{code}
 
 
@@ -544,6 +545,9 @@ data HscEnv
                -- reflect sucking in interface files.  They cache the state of
                -- external interface files, in effect.
 
+        hsc_NC_lock :: !(MVar ()),
+                -- ^ A lock used for updating the name cache.
+
        hsc_FC   :: {-# UNPACK #-} !(IORef FinderCache),
                -- ^ The cached result of performing finding in the file system
        hsc_MLC  :: {-# UNPACK #-} !(IORef ModLocationCache),