[project @ 2001-05-18 16:54:04 by simonmar]

[ghc-hetmet.git] / ghc / lib / std / PrelConc.lhs

diff --git a/ghc/lib/std/PrelConc.lhs b/ghc/lib/std/PrelConc.lhs
index 32240b4..0ffe3a9 100644 (file)
--- a/ghc/lib/std/PrelConc.lhs
+++ b/ghc/lib/std/PrelConc.lhs
@@ -1,5 +1,5 @@
 % -----------------------------------------------------------------------------
-% $Id: PrelConc.lhs,v 1.23 2001/02/15 10:02:43 simonmar Exp $
+% $Id: PrelConc.lhs,v 1.24 2001/05/18 16:54:05 simonmar Exp $
 %
 % (c) The University of Glasgow, 1994-2000
 %
@@ -36,6 +36,7 @@ module PrelConc
        , tryTakeMVar   -- :: MVar a -> IO (Maybe a)
        , tryPutMVar    -- :: MVar a -> a -> IO Bool
        , isEmptyMVar   -- :: MVar a -> IO Bool
+       , addMVarFinalizer -- :: MVar a -> IO () -> IO ()
 
     ) where
 
@@ -166,6 +167,11 @@ isEmptyMVar :: MVar a -> IO Bool
 isEmptyMVar (MVar mv#) = IO $ \ s# -> 
     case isEmptyMVar# mv# s# of
         (# s2#, flg #) -> (# s2#, not (flg ==# 0#) #)
+
+-- Like addForeignPtrFinalizer, but for MVars
+addMVarFinalizer :: MVar a -> IO () -> IO ()
+addMVarFinalizer (MVar m) finalizer = 
+  IO $ \s -> case mkWeak# m () finalizer s of { (# s1, w #) -> (# s1, () #) }
 \end{code}