Make the dynamic linker thread-safe.

[ghc-hetmet.git] / compiler / utils / Util.lhs

diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 62ab5f9..5cf020f 100644 (file)
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -42,7 +42,7 @@ module Util (
 
         -- * Comparisons
         isEqual, eqListBy,
-        thenCmp, cmpList, maybePrefixMatch,
+        thenCmp, cmpList,
         removeSpaces,
 
         -- * Transitive closures
@@ -65,7 +65,7 @@ module Util (
         doesDirNameExist,
         modificationTimeIfExists,
 
-        global, consIORef,
+        global, consIORef, globalMVar, globalEmptyMVar,
 
         -- * Filenames and paths
         Suffix,
@@ -83,6 +83,7 @@ import Data.IORef       ( IORef, newIORef )
 import System.IO.Unsafe ( unsafePerformIO )
 import Data.IORef       ( readIORef, writeIORef )
 import Data.List        hiding (group)
+import Control.Concurrent.MVar ( MVar, newMVar, newEmptyMVar )
 
 #ifdef DEBUG
 import qualified Data.List as List ( elem, notElem )
@@ -664,15 +665,6 @@ cmpList cmp (a:as) (b:bs)
 \end{code}
 
 \begin{code}
--- This (with a more general type) is Data.List.stripPrefix from GHC 6.8.
--- This definition can be removed once we require at least 6.8 to build.
-maybePrefixMatch :: String -> String -> Maybe String
-maybePrefixMatch []    rest = Just rest
-maybePrefixMatch (_:_) []   = Nothing
-maybePrefixMatch (p:pat) (r:rest)
-  | p == r    = maybePrefixMatch pat rest
-  | otherwise = Nothing
-
 removeSpaces :: String -> String
 removeSpaces = reverse . dropWhile isSpace . reverse . dropWhile isSpace
 \end{code}
@@ -708,6 +700,14 @@ consIORef var x = do
   writeIORef var (x:xs)
 \end{code}
 
+\begin{code}
+globalMVar :: a -> MVar a
+globalMVar a = unsafePerformIO (newMVar a)
+
+globalEmptyMVar :: MVar a
+globalEmptyMVar = unsafePerformIO newEmptyMVar
+\end{code}
+
 Module names:
 
 \begin{code}