Interruptible FFI calls with pthread_kill and CancelSynchronousIO. v4

[ghc-hetmet.git] / compiler / prelude / ForeignCall.lhs

diff --git a/compiler/prelude/ForeignCall.lhs b/compiler/prelude/ForeignCall.lhs
index e2f5320..a92cabd 100644 (file)
--- a/compiler/prelude/ForeignCall.lhs
+++ b/compiler/prelude/ForeignCall.lhs
@@ -10,10 +10,11 @@
 -- any warnings in the module. See
 --     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
+{-# LANGUAGE DeriveDataTypeable #-}
 
 module ForeignCall (
        ForeignCall(..),
-       Safety(..), playSafe,
+       Safety(..), playSafe, playInterruptible,
 
        CExportSpec(..), CLabelString, isCLabelString, pprCLabelString,
        CCallSpec(..), 
@@ -24,8 +25,10 @@ module ForeignCall (
 import FastString
 import Binary
 import Outputable
+import Module
 
 import Data.Char
+import Data.Data
 \end{code}
 
 
@@ -60,20 +63,31 @@ data Safety
                         -- which is now an alias for "safe". This information
                         -- is never used except to emit a deprecation warning.
 
+  | PlayInterruptible   -- Like PlaySafe, but additionally
+                        -- the worker thread running this foreign call may
+                        -- be unceremoniously killed, so it must be scheduled
+                        -- on an unbound thread.
+
   | PlayRisky          -- None of the above can happen; the call will return
                        -- without interacting with the runtime system at all
-  deriving ( Eq, Show )
+  deriving ( Eq, Show, Data, Typeable )
        -- Show used just for Show Lex.Token, I think
   {-! derive: Binary !-}
 
 instance Outputable Safety where
   ppr (PlaySafe False) = ptext (sLit "safe")
   ppr (PlaySafe True)  = ptext (sLit "threadsafe")
+  ppr PlayInterruptible = ptext (sLit "interruptible")
   ppr PlayRisky = ptext (sLit "unsafe")
 
 playSafe :: Safety -> Bool
 playSafe PlaySafe{} = True
+playSafe PlayInterruptible = True
 playSafe PlayRisky  = False
+
+playInterruptible :: Safety -> Bool
+playInterruptible PlayInterruptible = True
+playInterruptible _ = False
 \end{code}
 
 
@@ -88,6 +102,7 @@ data CExportSpec
   = CExportStatic              -- foreign export ccall foo :: ty
        CLabelString            -- C Name of exported function
        CCallConv
+  deriving (Data, Typeable)
   {-! derive: Binary !-}
 
 data CCallSpec
@@ -101,10 +116,26 @@ data CCallSpec
 The call target:
 
 \begin{code}
+
+-- | How to call a particular function in C-land.
 data CCallTarget
-  = StaticTarget  CLabelString  -- An "unboxed" ccall# to `fn'.
-  | DynamicTarget              -- First argument (an Addr#) is the function pointer
-  deriving( Eq )
+  -- An "unboxed" ccall# to named function in a particular package.
+  = StaticTarget  
+       CLabelString                    -- C-land name of label.
+
+       (Maybe PackageId)               -- What package the function is in.
+                                       -- If Nothing, then it's taken to be in the current package.
+                                       -- Note: This information is only used for PrimCalls on Windows.
+                                       --       See CLabel.labelDynamic and CoreToStg.coreToStgApp 
+                                       --       for the difference in representation between PrimCalls
+                                       --       and ForeignCalls. If the CCallTarget is representing
+                                       --       a regular ForeignCall then it's safe to set this to Nothing.
+
+  -- The first argument of the import is the name of a function pointer (an Addr#).
+  --   Used when importing a label as "foreign import ccall "dynamic" ..."
+  | DynamicTarget
+  
+  deriving( Eq, Data, Typeable )
   {-! derive: Binary !-}
 
 isDynamicTarget :: CCallTarget -> Bool
@@ -129,7 +160,7 @@ See: http://www.programmersheaven.com/2/Calling-conventions
 
 \begin{code}
 data CCallConv = CCallConv | StdCallConv | CmmCallConv | PrimCallConv
-  deriving (Eq)
+  deriving (Eq, Data, Typeable)
   {-! derive: Binary !-}
 
 instance Outputable CCallConv where
@@ -186,8 +217,14 @@ instance Outputable CCallSpec where
       gc_suf | playSafe safety = text "_GC"
             | otherwise       = empty
 
-      ppr_fun DynamicTarget     = text "__dyn_ccall" <> gc_suf <+> text "\"\""
-      ppr_fun (StaticTarget fn) = text "__ccall"     <> gc_suf <+> pprCLabelString fn
+      ppr_fun (StaticTarget fn Nothing)
+       = text "__pkg_ccall" <> gc_suf <+> pprCLabelString fn
+
+      ppr_fun (StaticTarget fn (Just pkgId))
+       = text "__pkg_ccall" <> gc_suf <+> ppr pkgId <+> pprCLabelString fn
+
+      ppr_fun DynamicTarget     
+        = text "__dyn_ccall" <> gc_suf <+> text "\"\""
 \end{code}
 
 
@@ -207,13 +244,16 @@ instance Binary Safety where
     put_ bh (PlaySafe aa) = do
            putByte bh 0
            put_ bh aa
-    put_ bh PlayRisky = do
+    put_ bh PlayInterruptible = do
            putByte bh 1
+    put_ bh PlayRisky = do
+           putByte bh 2
     get bh = do
            h <- getByte bh
            case h of
              0 -> do aa <- get bh
                      return (PlaySafe aa)
+             1 -> do return PlayInterruptible
              _ -> do return PlayRisky
 
 instance Binary CExportSpec where
@@ -237,16 +277,18 @@ instance Binary CCallSpec where
          return (CCallSpec aa ab ac)
 
 instance Binary CCallTarget where
-    put_ bh (StaticTarget aa) = do
+    put_ bh (StaticTarget aa ab) = do
            putByte bh 0
            put_ bh aa
+            put_ bh ab
     put_ bh DynamicTarget = do
            putByte bh 1
     get bh = do
            h <- getByte bh
            case h of
              0 -> do aa <- get bh
-                     return (StaticTarget aa)
+                      ab <- get bh
+                     return (StaticTarget aa ab)
              _ -> do return DynamicTarget
 
 instance Binary CCallConv where