[project @ 2004-12-23 00:02:41 by ralf]

[ghc-base.git] / Foreign / ForeignPtr.hs

diff --git a/Foreign/ForeignPtr.hs b/Foreign/ForeignPtr.hs
index 9705181..63e0b25 100644 (file)
--- a/Foreign/ForeignPtr.hs
+++ b/Foreign/ForeignPtr.hs
@@ -20,14 +20,29 @@ module Foreign.ForeignPtr
        -- * Finalised data pointers
          ForeignPtr
        , FinalizerPtr
+#ifdef __HUGS__
+       , FinalizerEnvPtr
+#endif
+       -- ** Basic operations
         , newForeignPtr
         , newForeignPtr_
         , addForeignPtrFinalizer
+#ifdef __HUGS__
+       , newForeignPtrEnv
+       , addForeignPtrFinalizerEnv
+#endif
        , withForeignPtr
+
+#ifdef __GLASGOW_HASKELL__
+       , finalizeForeignPtr
+#endif
+
+       -- ** Low-level operations
        , unsafeForeignPtrToPtr
        , touchForeignPtr
        , castForeignPtr
 
+       -- ** Allocating managed memory
        , mallocForeignPtr
        , mallocForeignPtrBytes
        , mallocForeignPtrArray
@@ -111,7 +126,7 @@ withForeignPtr :: ForeignPtr a -> (Ptr a -> IO b) -> IO b
 -- the action and use it after the action completes. All uses
 -- of the pointer should be inside the
 -- 'withForeignPtr' bracket.  The reason for
--- this unsafety is the same as for
+-- this unsafeness is the same as for
 -- 'unsafeForeignPtrToPtr' below: the finalizer
 -- may run earlier than expected, because the compiler can only
 -- track usage of the 'ForeignPtr' object, not
@@ -127,6 +142,19 @@ withForeignPtr fo io
        return r
 #endif /* ! __NHC__ */
 
+#ifdef __HUGS__
+-- | This variant of 'newForeignPtr' adds a finalizer that expects an
+-- environment in addition to the finalized pointer.  The environment
+-- that will be passed to the finalizer is fixed by the second argument to
+-- 'newForeignPtrEnv'.
+newForeignPtrEnv ::
+    FinalizerEnvPtr env a -> Ptr env -> Ptr a -> IO (ForeignPtr a)
+newForeignPtrEnv finalizer env p
+  = do fObj <- newForeignPtr_ p
+       addForeignPtrFinalizerEnv finalizer env fObj
+       return fObj
+#endif /* __HUGS__ */
+
 #ifndef __GLASGOW_HASKELL__
 mallocForeignPtr :: Storable a => IO (ForeignPtr a)
 mallocForeignPtr = do
@@ -137,13 +165,21 @@ mallocForeignPtrBytes :: Int -> IO (ForeignPtr a)
 mallocForeignPtrBytes n = do
   r <- mallocBytes n
   newForeignPtr finalizerFree r
-#endif /* __HUGS__ || __NHC__ */
+#endif /* !__GLASGOW_HASKELL__ */
 
+-- | This function is similar to 'Foreign.Marshal.Array.mallocArray',
+-- but yields a memory area that has a finalizer attached that releases
+-- the memory area.  As with 'mallocForeignPtr', it is not guaranteed that
+-- the block of memory was allocated by 'Foreign.Marshal.Alloc.malloc'.
 mallocForeignPtrArray :: Storable a => Int -> IO (ForeignPtr a)
 mallocForeignPtrArray  = doMalloc undefined
   where
-    doMalloc            :: Storable a => a -> Int -> IO (ForeignPtr a)
+    doMalloc            :: Storable b => b -> Int -> IO (ForeignPtr b)
     doMalloc dummy size  = mallocForeignPtrBytes (size * sizeOf dummy)
 
+-- | This function is similar to 'Foreign.Marshal.Array.mallocArray0',
+-- but yields a memory area that has a finalizer attached that releases
+-- the memory area.  As with 'mallocForeignPtr', it is not guaranteed that
+-- the block of memory was allocated by 'Foreign.Marshal.Alloc.malloc'.
 mallocForeignPtrArray0      :: Storable a => Int -> IO (ForeignPtr a)
 mallocForeignPtrArray0 size  = mallocForeignPtrArray (size + 1)