[project @ 2000-04-10 16:02:58 by simonpj]

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

diff --git a/ghc/lib/std/PrelConc.lhs b/ghc/lib/std/PrelConc.lhs
index 9801d77..f096db1 100644 (file)
--- a/ghc/lib/std/PrelConc.lhs
+++ b/ghc/lib/std/PrelConc.lhs
@@ -7,29 +7,34 @@
 Basic concurrency stuff
 
 \begin{code}
-{-# OPTIONS -fno-implicit-prelude #-}
-
-module PrelConc (
-
-               -- Thread Ids
-       ThreadId,
-
-               -- Forking and suchlike
-       forkIO, 
-       killThread,
-       par, fork, seq,
-       {-threadDelay, threadWaitRead, threadWaitWrite,-}
-
-               -- MVars
-       MVar
-     , newMVar
-     , newEmptyMVar
-     , takeMVar
-     , putMVar
-     , readMVar
-     , swapMVar
-       -- use with care (see comment.)
-     , isEmptyMVar
+{-# OPTIONS -fcompiling-prelude -fno-implicit-prelude #-}
+
+module PrelConc
+       ( ThreadId(..)
+
+       -- Forking and suchlike
+       , myThreadId    -- :: IO ThreadId
+       , killThread    -- :: ThreadId -> IO ()
+       , raiseInThread -- :: ThreadId -> Exception -> IO ()
+       , par           -- :: a -> b -> b
+       , seq           -- :: a -> b -> b
+       , yield         -- :: IO ()
+
+       -- Waiting
+       , threadDelay           -- :: Int -> IO ()
+       , threadWaitRead        -- :: Int -> IO ()
+       , threadWaitWrite       -- :: Int -> IO ()
+
+       -- MVars
+       , MVar          -- abstract
+       , newMVar       -- :: a -> IO (MVar a)
+       , newEmptyMVar  -- :: IO (MVar a)
+       , takeMVar      -- :: MVar a -> IO a
+       , putMVar       -- :: MVar a -> a -> IO ()
+       , readMVar      -- :: MVar a -> IO a
+       , swapMVar      -- :: MVar a -> a -> IO a
+       , isEmptyMVar   -- :: MVar a -> IO Bool
+
     ) where
 
 import PrelBase
@@ -37,8 +42,9 @@ import PrelErr ( parError, seqError )
 import PrelST          ( liftST )
 import PrelIOBase      ( IO(..), MVar(..), unsafePerformIO )
 import PrelBase                ( Int(..) )
+import PrelException    ( Exception(..), AsyncException(..) )
 
-infixr 0 `par`, `fork`
+infixr 0 `par`, `seq`
 \end{code}
 
 %************************************************************************
@@ -49,17 +55,27 @@ infixr 0 `par`, `fork`
 
 \begin{code}
 data ThreadId = ThreadId ThreadId#
--- ToDo: data ThreadId = ThreadId (WeakPair ThreadId# ())
--- But since ThreadId# is unlifted, the WeakPair type must use open
+-- ToDo: data ThreadId = ThreadId (Weak ThreadId#)
+-- But since ThreadId# is unlifted, the Weak type must use open
 -- type variables.
 
-forkIO :: IO () -> IO ThreadId
-forkIO action = IO $ \ s -> 
-   case (fork# action s) of (# s1, id #) -> (# s1, ThreadId id #)
+--forkIO has now been hoisted out into the Concurrent library.
 
 killThread :: ThreadId -> IO ()
 killThread (ThreadId id) = IO $ \ s ->
-   case (killThread# id s) of s1 -> (# s1, () #)
+   case (killThread# id (AsyncException ThreadKilled) s) of s1 -> (# s1, () #)
+
+raiseInThread :: ThreadId -> Exception -> IO ()
+raiseInThread (ThreadId id) ex = IO $ \ s ->
+   case (killThread# id ex s) of s1 -> (# s1, () #)
+
+myThreadId :: IO ThreadId
+myThreadId = IO $ \s ->
+   case (myThreadId# s) of (# s1, id #) -> (# s1, ThreadId id #)
+
+yield :: IO ()
+yield = IO $ \s -> 
+   case (yield# s) of s1 -> (# s1, () #)
 
 -- "seq" is defined a bit wierdly (see below)
 --
@@ -76,18 +92,9 @@ killThread (ThreadId id) = IO $ \ s ->
 seq :: a -> b -> b
 seq  x y = case (seq#  x) of { 0# -> seqError; _ -> y }
 
-par, fork :: a -> b -> b
-
 {-# INLINE par  #-}
-{-# INLINE fork #-}
-#if defined(__PARALLEL_HASKELL__) || defined (__GRANSIM__)
+par :: a -> b -> b
 par  x y = case (par# x) of { 0# -> parError; _ -> y }
-#else
-par  _ y = y
-#endif
-
-fork x y = unsafePerformIO (forkIO (x `seq` return ())) `seq` y
-
 \end{code}
 
 %************************************************************************
@@ -107,9 +114,6 @@ writes.
 \begin{code}
 --Defined in IOBase to avoid cycle: data MVar a = MVar (SynchVar# RealWorld a)
 
-instance Eq (MVar a) where
-       (MVar mvar1#) == (MVar mvar2#) = sameMVar# mvar1# mvar2#
-
 newEmptyMVar  :: IO (MVar a)
 
 newEmptyMVar = IO $ \ s# ->
@@ -185,19 +189,9 @@ specified file descriptor is available for reading (just like select).
 @threadWaitWrite@ is similar, but for writing on a file descriptor.
 
 \begin{code}
-{- Not yet -- SDM 
 threadDelay, threadWaitRead, threadWaitWrite :: Int -> IO ()
 
-threadDelay (I# x#) = IO $ \ s# ->
-    case delay# x# s# of
-      s2# -> (# s2#, () #)
-
-threadWaitRead (I# x#) = IO $ \ s# -> 
-    case waitRead# x# s# of
-      s2# -> (# s2#, () #)
-
-threadWaitWrite (I# x#) = IO $ \ s# ->
-    case waitWrite# x# s# of
-      s2# -> (# s2#, () #)
--}
+threadDelay     (I# ms) = IO $ \s -> case delay# ms s     of s -> (# s, () #)
+threadWaitRead  (I# fd) = IO $ \s -> case waitRead# fd s  of s -> (# s, () #)
+threadWaitWrite (I# fd) = IO $ \s -> case waitWrite# fd s of s -> (# s, () #)
 \end{code}