X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Foreign%2FForeignPtr.hs;h=21485dba2ea036600b27d82e3b60879dcceab5cf;hb=6b1a36a595eddf1e124529646afdb75c76a9966d;hp=fce4a130df45d8a3addd3c1152fc5d51ea32b070;hpb=7196f1ea1790dc0ef7986ae6757bdcf46a286e3f;p=haskell-directory.git

diff --git a/Foreign/ForeignPtr.hs b/Foreign/ForeignPtr.hs
index fce4a13..21485db 100644
--- a/Foreign/ForeignPtr.hs
+++ b/Foreign/ForeignPtr.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Foreign.ForeignPtr
@@ -20,19 +20,33 @@ module Foreign.ForeignPtr
 	-- * Finalised data pointers
 	  ForeignPtr
 	, FinalizerPtr
+#if defined(__HUGS__) || defined(__GLASGOW_HASKELL__)
+	, FinalizerEnvPtr
+#endif
+	-- ** Basic operations
         , newForeignPtr
+        , newForeignPtr_
         , addForeignPtrFinalizer
+#if defined(__HUGS__) || defined(__GLASGOW_HASKELL__)
+	, newForeignPtrEnv
+	, addForeignPtrFinalizerEnv
+#endif
 	, withForeignPtr
-	, foreignPtrToPtr
+
+#ifdef __GLASGOW_HASKELL__
+	, finalizeForeignPtr
+#endif
+
+	-- ** Low-level operations
+	, unsafeForeignPtrToPtr
 	, touchForeignPtr
 	, castForeignPtr
 
-#ifndef __NHC__
+	-- ** Allocating managed memory
 	, mallocForeignPtr
 	, mallocForeignPtrBytes
 	, mallocForeignPtrArray
 	, mallocForeignPtrArray0
-#endif
         ) 
 	where
 
@@ -41,12 +55,16 @@ import Foreign.Ptr
 #ifdef __NHC__
 import NHC.FFI
   ( ForeignPtr
+  , FinalizerPtr
   , newForeignPtr
+  , newForeignPtr_
   , addForeignPtrFinalizer
   , withForeignPtr
-  , foreignPtrToPtr
+  , unsafeForeignPtrToPtr
   , touchForeignPtr
   , castForeignPtr
+  , Storable(sizeOf)
+  , malloc, mallocBytes, finalizerFree
   )
 #endif
 
@@ -68,22 +86,33 @@ import GHC.ForeignPtr
 
 #if !defined(__NHC__) && !defined(__GLASGOW_HASKELL__)
 import Foreign.Marshal.Alloc	( malloc, mallocBytes, finalizerFree )
-import Data.Dynamic
-
-#include "Dynamic.h"
-INSTANCE_TYPEABLE1(ForeignPtr,foreignPtrTc,"ForeignPtr")
 
 instance Eq (ForeignPtr a) where 
-    p == q  =  foreignPtrToPtr p == foreignPtrToPtr q
+    p == q  =  unsafeForeignPtrToPtr p == unsafeForeignPtrToPtr q
 
 instance Ord (ForeignPtr a) where 
-    compare p q  =  compare (foreignPtrToPtr p) (foreignPtrToPtr q)
+    compare p q  =  compare (unsafeForeignPtrToPtr p) (unsafeForeignPtrToPtr q)
 
 instance Show (ForeignPtr a) where
-    showsPrec p f = showsPrec p (foreignPtrToPtr f)
+    showsPrec p f = showsPrec p (unsafeForeignPtrToPtr f)
 #endif
 
+
 #ifndef __NHC__
+newForeignPtr :: FinalizerPtr a -> Ptr a -> IO (ForeignPtr a)
+-- ^Turns a plain memory reference into a foreign pointer, and
+-- associates a finaliser with the reference.  The finaliser will be executed
+-- after the last reference to the foreign object is dropped.  Note that there
+-- is no guarantee on how soon the finaliser is executed after the last
+-- reference was dropped; this depends on the details of the Haskell storage
+-- manager.  Indeed, there is no guarantee that the finalizer is executed at
+-- all; a program may exit with finalizers outstanding.  (This is true
+-- of GHC, other implementations may give stronger guarantees).
+newForeignPtr finalizer p
+  = do fObj <- newForeignPtr_ p
+       addForeignPtrFinalizer finalizer fObj
+       return fObj
+
 withForeignPtr :: ForeignPtr a -> (Ptr a -> IO b) -> IO b
 -- ^This is a way to look at the pointer living inside a
 -- foreign object.  This function takes a function which is
@@ -94,8 +123,8 @@ 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
--- 'foreignPtrToPtr' below: the finalizer
+-- 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
 -- a 'Ptr' object made from it.
@@ -105,30 +134,67 @@ withForeignPtr :: ForeignPtr a -> (Ptr a -> IO b) -> IO b
 -- 'ForeignPtr', using the operations from the
 -- 'Storable' class.
 withForeignPtr fo io
-  = do r <- io (foreignPtrToPtr fo)
+  = do r <- io (unsafeForeignPtrToPtr fo)
        touchForeignPtr fo
        return r
 #endif /* ! __NHC__ */
 
-#ifdef __HUGS__
+#if defined(__HUGS__) || defined(__GLASGOW_HASKELL__)
+-- | 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__ */
+
+#ifdef __GLASGOW_HASKELL__
+type FinalizerEnvPtr env a = FunPtr (Ptr env -> Ptr a -> IO ())
+
+-- | like 'addForeignPtrFinalizerEnv' but allows the finalizer to be
+-- passed an additional environment parameter to be passed to the
+-- finalizer.  The environment passed to the finalizer is fixed by the
+-- second argument to 'addForeignPtrFinalizerEnv'
+addForeignPtrFinalizerEnv ::
+  FinalizerEnvPtr env a -> Ptr env -> ForeignPtr a -> IO ()
+addForeignPtrFinalizerEnv finalizer env fptr = 
+  addForeignPtrConcFinalizer fptr 
+	(mkFinalizerEnv finalizer env (unsafeForeignPtrToPtr fptr))
+
+foreign import ccall "dynamic" 
+  mkFinalizerEnv :: FinalizerEnvPtr env a -> Ptr env -> Ptr a -> IO ()
+#endif
+
+
+#ifndef __GLASGOW_HASKELL__
 mallocForeignPtr :: Storable a => IO (ForeignPtr a)
 mallocForeignPtr = do
   r <- malloc
-  newForeignPtr r finalizerFree
+  newForeignPtr finalizerFree r
 
 mallocForeignPtrBytes :: Int -> IO (ForeignPtr a)
 mallocForeignPtrBytes n = do
   r <- mallocBytes n
-  newForeignPtr r finalizerFree
-#endif /* __HUGS__ */
+  newForeignPtr finalizerFree r
+#endif /* !__GLASGOW_HASKELL__ */
 
-#ifndef __NHC__
+-- | 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)
-#endif