7c72da4 · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

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Use modifyMVar for exception safety

7c72da4Leon P Smith15 years ago

src/Database/PostgreSQL/Simple.hs+3−7

@@ -730,10 +730,9 @@ getTypename :: Connection -> PQ.Oid -> IO ByteString

730getTypename conn@Connection{..} oid =

731 case oid2builtin oid of

732 Just builtin -> return $! builtin2typname builtin

733− Nothing -> do

733+ Nothing -> modifyMVar connectionObjects $ \oidmap -> do

734− oidmap <- takeMVar connectionObjects

735 case IntMap.lookup (oid2int oid) oidmap of

734 case IntMap.lookup (oid2int oid) oidmap of

736− Just name -> putMVar connectionObjects oidmap >> return name

735+ Just name -> return (oidmap, name)

737 Nothing -> do

736 Nothing -> do

738 names <- query conn "SELECT typname FROM pg_type WHERE oid=?"

737 names <- query conn "SELECT typname FROM pg_type WHERE oid=?"

739 (Only oid)

738 (Only oid)

@@ -747,7 +746,4 @@ getTypename conn@Connection{..} oid =

747 _ -> fail "typename query returned more than one result"

746 _ -> fail "typename query returned more than one result"

748 -- oid is a primary key, so the query should

747 -- oid is a primary key, so the query should

749 -- never return more than one result

748 -- never return more than one result

750− putMVar connectionObjects (IntMap.insert (oid2int oid) name oidmap)

749+ return (IntMap.insert (oid2int oid) name oidmap, name)

751− return name

752− `onException` do

753− putMVar connectionObjects oidmap