[project @ 2004-02-12 21:23:48 by krasimir]

[ghc-base.git] / GHC / Conc.lhs

diff --git a/GHC/Conc.lhs b/GHC/Conc.lhs
index 279681b..86ba270 100644 (file)
--- a/GHC/Conc.lhs
+++ b/GHC/Conc.lhs
@@ -26,7 +26,6 @@ module GHC.Conc
        , pseq          -- :: a -> b -> b
        , yield         -- :: IO ()
        , labelThread   -- :: ThreadId -> String -> IO ()
-       , forkProcessPrim -- :: IO Int
 
        -- Waiting
        , threadDelay           -- :: Int -> IO ()
@@ -154,29 +153,6 @@ labelThread (ThreadId t) str = IO $ \ s ->
        adr = byteArrayContents# ps in
      case (labelThread# t adr s) of s1 -> (# s1, () #)
 
-{- | This function is a replacement for 'System.Posix.Process.forkProcessAll':
-This implementation /will stop all other Concurrent Haskell threads/ in the
-(heavyweight) forked copy.
-'forkProcessPrim' returns the pid of the child process to the parent, 0 to the
-child, and a value less than 0 in case of errors. See also:
-'System.Posix.Process.forkProcess' in package @unix@.
-
-Without this function, you need excessive and often impractical
-explicit synchronization using the regular Concurrent Haskell constructs to assure
-that only the desired thread is running after the fork().
-
-The stopped threads are /not/ garbage collected! This behaviour may change in
-future releases.
-
-NOTE: currently, main threads are not stopped in the child process.
-To work around this problem, call 'forkProcessPrim' from the main thread. 
--}
-
--- XXX RTS should know about 'pid_t'.
-
-forkProcessPrim :: IO Int
-forkProcessPrim = IO $ \s -> case (forkProcess# s) of (# s1, id #) -> (# s1, (I# id) #)
-
 --     Nota Bene: 'pseq' used to be 'seq'
 --                but 'seq' is now defined in PrelGHC
 --
@@ -295,13 +271,17 @@ specified file descriptor is available for reading (just like select).
 @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 (GHC only).
+-- | 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.
 --
--- 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.
 threadDelay :: Int -> IO ()
 
 -- | Block the current thread until data is available to read on the