[commit: base] master: Fix hClose002 with the threaded RTS IO manager (80b02b2)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

https://github.com/ghc/packages-base/commit/80b02b2a1ebd84c853a9479a7a36c923058e7ce8

>---------------------------------------------------------------

commit 80b02b2a1ebd84c853a9479a7a36c923058e7ce8
Author: Ian Lynagh <ian at well-typed.com>
Date:   Sun Jun 16 20:16:19 2013 +0100

    Fix hClose002 with the threaded RTS IO manager
    
    If 'close fd' failed, then the MVars in the callbackTables would be
    left empty, which caused deadlocks when we tried to 'take' them again.
    
    Now we use 'finally' to ensure that they are refilled even if 'close'
    throws an exception.

>---------------------------------------------------------------

 GHC/Event/Thread.hs |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/GHC/Event/Thread.hs b/GHC/Event/Thread.hs
index cbef3c3..ca8ed1e 100644
--- a/GHC/Event/Thread.hs
+++ b/GHC/Event/Thread.hs
@@ -103,8 +103,7 @@ closeFdWith close fd = do
                       (\mgr table -> M.closeFd_ mgr table fd)
                       mgrs
                       tables
-    close fd
-    zipWithM_ finish mgrs tableAndCbApps
+    close fd `finally` zipWithM_ finish mgrs tableAndCbApps
   where
     finish mgr (table', cbApp) = do
       putMVar (M.callbackTableVar mgr fd) table'