--
-----------------------------------------------------------------------------
+#include "config.h"
module GHC.Conc
( ThreadId(..)
, par -- :: a -> b -> b
, pseq -- :: a -> b -> b
, yield -- :: IO ()
- , labelThread -- :: String -> IO ()
- , forkProcess -- :: IO Int
+ , labelThread -- :: ThreadId -> String -> IO ()
-- Waiting
, threadDelay -- :: Int -> IO ()
, isEmptyMVar -- :: MVar a -> IO Bool
, addMVarFinalizer -- :: MVar a -> IO () -> IO ()
- ) where
+#ifdef mingw32_TARGET_OS
+ , asyncRead -- :: Int -> Int -> Int -> Ptr a -> IO (Int, Int)
+ , asyncWrite -- :: Int -> Int -> Int -> Ptr a -> IO (Int, Int)
+ , asyncDoProc -- :: FunPtr (Ptr a -> IO Int) -> Ptr a -> IO Int
+
+ , asyncReadBA -- :: Int -> Int -> Int -> Int -> MutableByteArray# RealWorld -> IO (Int, Int)
+ , asyncWriteBA -- :: Int -> Int -> Int -> Int -> MutableByteArray# RealWorld -> IO (Int, Int)
+#endif
+ ) where
import Data.Maybe
import GHC.Base
-import GHC.IOBase ( IO(..), MVar(..) )
+import GHC.IOBase ( IO(..), MVar(..), ioException, IOException(..), IOErrorType(..) )
+import GHC.Num ( fromInteger, negate )
+import GHC.Real ( fromIntegral )
import GHC.Base ( Int(..) )
import GHC.Exception ( Exception(..), AsyncException(..) )
import GHC.Pack ( packCString# )
+import GHC.Ptr ( Ptr(..), plusPtr, FunPtr(..) )
infixr 0 `par`, `pseq`
\end{code}
useful when debugging or diagnosing the behaviour of a concurrent
program.
-NOTE: in GHC, if you have a 'ThreadId', you essentially have
+/Note/: in GHC, if you have a 'ThreadId', you essentially have
a pointer to the thread itself. This means the thread itself can\'t be
garbage collected until you drop the 'ThreadId'.
This misfeature will hopefully be corrected at a later date.
+
+/Note/: Hugs does not provide any operations on other threads;
+it defines 'ThreadId' as a synonym for ().
-}
--forkIO has now been hoisted out into the Concurrent library.
-{- | 'killThread' terminates the given thread (Note: 'killThread' is
-not implemented in Hugs). Any work already done by the thread isn\'t
+{- | 'killThread' terminates the given thread (GHC only).
+Any work already done by the thread isn\'t
lost: the computation is suspended until required by another thread.
The memory used by the thread will be garbage collected if it isn\'t
-referenced from anywhere. The 'killThread' function may be defined in
+referenced from anywhere. The 'killThread' function is defined in
terms of 'throwTo':
-> killThread = throwTo (AsyncException ThreadKilled)
+> killThread tid = throwTo tid (AsyncException ThreadKilled)
+
-}
killThread :: ThreadId -> IO ()
-killThread (ThreadId id) = IO $ \ s ->
- case (killThread# id (AsyncException ThreadKilled) s) of s1 -> (# s1, () #)
+killThread tid = throwTo tid (AsyncException ThreadKilled)
-{- | 'throwTo' raises an arbitrary exception in the target thread.
+{- | 'throwTo' raises an arbitrary exception in the target thread (GHC only).
'throwTo' does not return until the exception has been raised in the
target thread. The calling thread can thus be certain that the target
throwTo (ThreadId id) ex = IO $ \ s ->
case (killThread# id ex s) of s1 -> (# s1, () #)
--- | Returns the 'ThreadId' of the calling thread.
+-- | Returns the 'ThreadId' of the calling thread (GHC only).
myThreadId :: IO ThreadId
myThreadId = IO $ \s ->
case (myThreadId# s) of (# s1, id #) -> (# s1, ThreadId id #)
yield = IO $ \s ->
case (yield# s) of s1 -> (# s1, () #)
-labelThread :: String -> IO ()
-labelThread str = IO $ \ s ->
+{- | 'labelThread' stores a string as identifier for this thread if
+you built a RTS with debugging support. This identifier will be used in
+the debugging output to make distinction of different threads easier
+(otherwise you only have the thread state object\'s address in the heap).
+
+Other applications like the graphical Concurrent Haskell Debugger
+(<http://www.informatik.uni-kiel.de/~fhu/chd/>) may choose to overload
+'labelThread' for their purposes as well.
+-}
+
+labelThread :: ThreadId -> String -> IO ()
+labelThread (ThreadId t) str = IO $ \ s ->
let ps = packCString# str
adr = byteArrayContents# ps in
- case (labelThread# adr s) of s1 -> (# s1, () #)
-
-forkProcess :: IO Int
-forkProcess = IO $ \s -> case (forkProcess# s) of (# s1, id #) -> (# s1, (I# id) #)
+ case (labelThread# t adr s) of s1 -> (# s1, () #)
-- Nota Bene: 'pseq' used to be 'seq'
-- but 'seq' is now defined in PrelGHC
-- 'putMVar' will wait until it becomes empty.
--
-- If several threads are competing to fill the same 'MVar', one is
--- chosen to continue at random with the 'MVar' becomes empty.
+-- chosen to continue at random when the 'MVar' becomes empty.
putMVar :: MVar a -> a -> IO ()
putMVar (MVar mvar#) x = IO $ \ s# ->
case putMVar# mvar# x s# of
case isEmptyMVar# mv# s# of
(# s2#, flg #) -> (# s2#, not (flg ==# 0#) #)
--- |Add a finalizer to an 'MVar'. See "Foreign.ForeignPtr" and
+-- |Add a finalizer to an 'MVar' (GHC only). See "Foreign.ForeignPtr" and
-- "System.Mem.Weak" for more about finalizers.
addMVarFinalizer :: MVar a -> IO () -> IO ()
addMVarFinalizer (MVar m) finalizer =
@threadWaitWrite@ is similar, but for writing on a file descriptor.
\begin{code}
--- |The 'threadDelay' operation will cause the current thread to
--- suspend for a given number of microseconds. Note that the resolution
--- used by the Haskell runtime system\'s internal timer together with the
--- fact that the thread may take some time to be rescheduled after the
--- time has expired, means that the accuracy is more like 1\/50 second.
+-- | Suspends the current thread for a given number of microseconds
+-- (GHC only).
+--
+-- Note that the resolution used by the Haskell runtime system's
+-- internal timer is 1\/50 second, and 'threadDelay' will round its
+-- argument up to the nearest multiple of this resolution.
+--
+-- There is no guarantee that the thread will be rescheduled promptly
+-- when the delay has expired, but the thread will never continue to
+-- run /earlier/ than specified.
+--
threadDelay :: Int -> IO ()
-- | Block the current thread until data is available to read on the
--- given file descriptor.
+-- given file descriptor (GHC only).
threadWaitRead :: Int -> IO ()
-- | Block the current thread until data can be written to the
--- given file descriptor.
+-- given file descriptor (GHC only).
threadWaitWrite :: Int -> IO ()
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, () #)
+
+#ifdef mingw32_TARGET_OS
+
+-- Note: threadDelay, threadWaitRead and threadWaitWrite aren't really functional
+-- on Win32, but left in there because lib code (still) uses them (the manner
+-- in which they're used doesn't cause problems on a Win32 platform though.)
+
+asyncRead :: Int -> Int -> Int -> Ptr a -> IO (Int, Int)
+asyncRead (I# fd) (I# isSock) (I# len) (Ptr buf) =
+ IO $ \s -> case asyncRead# fd isSock len buf s of
+ (# s, len#, err# #) -> (# s, (I# len#, I# err#) #)
+
+asyncWrite :: Int -> Int -> Int -> Ptr a -> IO (Int, Int)
+asyncWrite (I# fd) (I# isSock) (I# len) (Ptr buf) =
+ IO $ \s -> case asyncWrite# fd isSock len buf s of
+ (# s, len#, err# #) -> (# s, (I# len#, I# err#) #)
+
+asyncDoProc :: FunPtr (Ptr a -> IO Int) -> Ptr a -> IO Int
+asyncDoProc (FunPtr proc) (Ptr param) =
+ -- the 'length' value is ignored; simplifies implementation of
+ -- the async*# primops to have them all return the same result.
+ IO $ \s -> case asyncDoProc# proc param s of
+ (# s, len#, err# #) -> (# s, I# err# #)
+
+-- to aid the use of these primops by the IO Handle implementation,
+-- provide the following convenience funs:
+
+-- this better be a pinned byte array!
+asyncReadBA :: Int -> Int -> Int -> Int -> MutableByteArray# RealWorld -> IO (Int,Int)
+asyncReadBA fd isSock len off bufB =
+ asyncRead fd isSock len ((Ptr (byteArrayContents# (unsafeCoerce# bufB))) `plusPtr` off)
+
+asyncWriteBA :: Int -> Int -> Int -> Int -> MutableByteArray# RealWorld -> IO (Int,Int)
+asyncWriteBA fd isSock len off bufB =
+ asyncWrite fd isSock len ((Ptr (byteArrayContents# (unsafeCoerce# bufB))) `plusPtr` off)
+
+#endif
\end{code}
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