Merge pull request #24 from well-typed/jdral/issue-19

Add `withIOCtx`

cabal.project

@@ -1 +1,6 @@
+index-state:
+  -- Bump this if you need newer packages from Hackage
+  -- current date: quickcheck-lockstep-0.6.0
+  , hackage.haskell.org 2024-12-10T00:00:00Z
+
 packages: .

src/System/IO/BlockIO.hs

@@ -7,9 +7,10 @@ module System.IO.BlockIO (
 
     -- * I\/O context and initialisation
     IOCtx,
-    initIOCtx,
     IOCtxParams(..),
     defaultIOCtxParams,
+    withIOCtx,
+    initIOCtx,
     closeIOCtx,
 
     -- * Performing I\/O
@@ -34,7 +35,7 @@ import Control.Concurrent.MVar
 import Control.Concurrent.QSemN
 import Control.Concurrent.Chan
 import Control.Exception (mask_, throw, ArrayException(UndefinedElement),
-                          finally, assert, throwIO)
+                          finally, assert, throwIO, bracket)
 import System.IO.Error
 import GHC.IO.Exception (IOErrorType(ResourceVanished, InvalidArgument))
 
@@ -90,6 +91,9 @@ defaultIOCtxParams =
     ioctxConcurrencyLimit = 64 * 3
   }
 
+withIOCtx :: IOCtxParams -> (IOCtx -> IO a) -> IO a
+withIOCtx params = bracket (initIOCtx params) closeIOCtx
+
 initIOCtx :: IOCtxParams -> IO IOCtx
 initIOCtx IOCtxParams {ioctxBatchSizeLimit, ioctxConcurrencyLimit} = do
 #if MIN_VERSION_base(4,16,0)