Remove non-directory stuff (of base), and rename package to "directory"

[haskell-directory.git] / Control / Concurrent / QSemN.hs

diff --git a/Control/Concurrent/QSemN.hs b/Control/Concurrent/QSemN.hs
deleted file mode 100644 (file)
index 56c5e50..0000000
--- a/Control/Concurrent/QSemN.hs
+++ /dev/null
@@ -1,70 +0,0 @@
------------------------------------------------------------------------------
--- |
--- Module      :  Control.Concurrent.QSemN
--- Copyright   :  (c) The University of Glasgow 2001
--- License     :  BSD-style (see the file libraries/base/LICENSE)
--- 
--- Maintainer  :  libraries@haskell.org
--- Stability   :  experimental
--- Portability :  non-portable (concurrency)
---
--- Quantity semaphores in which each thread may wait for an arbitrary
--- \"amount\".
---
------------------------------------------------------------------------------
-
-module Control.Concurrent.QSemN
-       (  -- * General Quantity Semaphores
-         QSemN,        -- abstract
-         newQSemN,     -- :: Int   -> IO QSemN
-         waitQSemN,    -- :: QSemN -> Int -> IO ()
-         signalQSemN   -- :: QSemN -> Int -> IO ()
-      ) where
-
-import Prelude
-
-import Control.Concurrent.MVar
-import Data.Typeable
-
-#include "Typeable.h"
-
--- |A 'QSemN' is a quantity semaphore, in which the available
--- \"quantity\" may be signalled or waited for in arbitrary amounts.
-newtype QSemN = QSemN (MVar (Int,[(Int,MVar ())]))
-
-INSTANCE_TYPEABLE0(QSemN,qSemNTc,"QSemN")
-
--- |Build a new 'QSemN' with a supplied initial quantity.
-newQSemN :: Int -> IO QSemN 
-newQSemN init = do
-   sem <- newMVar (init,[])
-   return (QSemN sem)
-
--- |Wait for the specified quantity to become available
-waitQSemN :: QSemN -> Int -> IO ()
-waitQSemN (QSemN sem) sz = do
-  (avail,blocked) <- takeMVar sem   -- gain ex. access
-  if (avail - sz) >= 0 then
-       -- discharging 'sz' still leaves the semaphore
-       -- in an 'unblocked' state.
-     putMVar sem (avail-sz,blocked)
-   else do
-     block <- newEmptyMVar
-     putMVar sem (avail, blocked++[(sz,block)])
-     takeMVar block
-
--- |Signal that a given quantity is now available from the 'QSemN'.
-signalQSemN :: QSemN -> Int  -> IO ()
-signalQSemN (QSemN sem) n = do
-   (avail,blocked)   <- takeMVar sem
-   (avail',blocked') <- free (avail+n) blocked
-   putMVar sem (avail',blocked')
- where
-   free avail []    = return (avail,[])
-   free avail ((req,block):blocked)
-     | avail >= req = do
-       putMVar block ()
-       free (avail-req) blocked
-     | otherwise    = do
-       (avail',blocked') <- free avail blocked
-        return (avail',(req,block):blocked')