From 3160b1426c25340503b5ab216965e30509cd8416 Mon Sep 17 00:00:00 2001
From: Bernhard Urban <lewurm@gmail.com>
Date: Fri, 18 May 2012 11:30:33 +0200
Subject: [PATCH] refactor: use `unsafePerformIO hack' for global var

---
 Mate.hs            |  1 -
 Mate/MethodPool.hs |  4 ---
 Mate/Types.hs      | 64 +++++++++++++++++++---------------------------
 ffi/trap.c         | 12 ---------
 4 files changed, 26 insertions(+), 55 deletions(-)

diff --git a/Mate.hs b/Mate.hs
index 0275e81..02c9969 100644
--- a/Mate.hs
+++ b/Mate.hs
@@ -23,7 +23,6 @@ main ::  IO ()
 main = do
   args <- getArgs
   register_signal
-  initMethodPool
   case args of
     [clspath] -> do
       let bclspath = B.pack $ map (fromIntegral . ord) clspath
diff --git a/Mate/MethodPool.hs b/Mate/MethodPool.hs
index 21c1795..16890c8 100644
--- a/Mate/MethodPool.hs
+++ b/Mate/MethodPool.hs
@@ -137,10 +137,6 @@ loadNativeFunction sym = do
 --   mmap2ptr mmap >>= set_mmap
 --   demo_mmap -- access Data.Map from C
 
-initMethodPool :: IO ()
-initMethodPool = ctx2ptr emptyMateCtx >>= set_mate_context
-
-
 addMethodRef :: Word32 -> MethodInfo -> [B.ByteString] -> IO ()
 addMethodRef entry (MethodInfo mmname _ msig) clsnames = do
   mmap <- getMethodMap
diff --git a/Mate/Types.hs b/Mate/Types.hs
index 2cdad11..79b0396 100644
--- a/Mate/Types.hs
+++ b/Mate/Types.hs
@@ -9,8 +9,8 @@ import qualified Data.Map as M
 import qualified Data.ByteString.Lazy as B
 import Codec.Binary.UTF8.String hiding (encode,decode)
 
-import Foreign.Ptr
-import Foreign.StablePtr
+import Data.IORef
+import System.IO.Unsafe
 
 import JVM.ClassFile
 import JVM.Assembler
@@ -108,14 +108,6 @@ toString :: B.ByteString -> String
 toString bstr = decodeString $ map (chr . fromIntegral) $ B.unpack bstr
 
 
--- those functions are for the "global map hax"
--- TODO(bernhard): other solution please
-foreign import ccall "set_mate_context"
-  set_mate_context :: Ptr () -> IO ()
-
-foreign import ccall "get_mate_context"
-  get_mate_context :: IO (Ptr ())
-
 data MateCtx = MateCtx {
   ctxMethodMap :: MethodMap,
   ctxTrapMap :: TrapMap,
@@ -128,87 +120,83 @@ data MateCtx = MateCtx {
 emptyMateCtx :: MateCtx
 emptyMateCtx = MateCtx M.empty M.empty M.empty M.empty M.empty M.empty M.empty
 
-ctx2ptr :: MateCtx -> IO (Ptr ())
-ctx2ptr ctx = do
-  ptr <- newStablePtr ctx
-  return $ castStablePtrToPtr ptr
-
-ptr2ctx :: Ptr () -> IO MateCtx
-ptr2ctx ptr = deRefStablePtr (castPtrToStablePtr ptr :: StablePtr MateCtx)
+mateCtx :: IORef MateCtx
+{-# NOINLINE mateCtx #-}
+mateCtx = unsafePerformIO $ newIORef emptyMateCtx
 
 
 setMethodMap :: MethodMap -> IO ()
 setMethodMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxMethodMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxMethodMap = m }
 
 getMethodMap :: IO MethodMap
 getMethodMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxMethodMap ctx
 
 
 setTrapMap :: TrapMap -> IO ()
 setTrapMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxTrapMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxTrapMap = m }
 
 getTrapMap :: IO TrapMap
 getTrapMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxTrapMap ctx
 
 
 setClassMap :: ClassMap -> IO ()
 setClassMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxClassMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxClassMap = m }
 
 getClassMap :: IO ClassMap
 getClassMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxClassMap ctx
 
 
 setVirtualMap :: VirtualMap -> IO ()
 setVirtualMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxVirtualMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxVirtualMap = m }
 
 getVirtualMap :: IO VirtualMap
 getVirtualMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxVirtualMap ctx
 
 
 setStringMap :: StringMap -> IO ()
 setStringMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxStringMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxStringMap = m }
 
 getStringMap :: IO StringMap
 getStringMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxStringMap ctx
 
 
 setInterfaceMap :: InterfaceMap -> IO ()
 setInterfaceMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxInterfaceMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxInterfaceMap = m }
 
 getInterfaceMap :: IO InterfaceMap
 getInterfaceMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxInterfaceMap ctx
 
 
 setInterfaceMethodMap :: InterfaceMethodMap -> IO ()
 setInterfaceMethodMap m = do
-  ctx <- get_mate_context >>= ptr2ctx
-  ctx2ptr ctx { ctxInterfaceMethodMap = m } >>= set_mate_context
+  ctx <- readIORef mateCtx
+  writeIORef mateCtx $ ctx { ctxInterfaceMethodMap = m }
 
 getInterfaceMethodMap :: IO InterfaceMethodMap
 getInterfaceMethodMap = do
-  ctx <- get_mate_context >>= ptr2ctx
+  ctx <- readIORef mateCtx
   return $ ctxInterfaceMethodMap ctx
diff --git a/ffi/trap.c b/ffi/trap.c
index 0302c5e..157358b 100644
--- a/ffi/trap.c
+++ b/ffi/trap.c
@@ -32,18 +32,6 @@ unsigned int mallocObject(int);
 #define dprintf(args...)
 #endif
 
-void *mate_ctx = NULL;
-
-void *get_mate_context()
-{
-	return mate_ctx;
-}
-
-void *set_mate_context(void *ctx)
-{
-	mate_ctx = ctx;
-}
-
 void mainresult(unsigned int a)
 {
 	dprintf("mainresult: 0x%08x\n", a);
-- 
2.25.1