[PATCH stable-2.12] Improve documentation for closing function in UDSServer

['Petr Pudlak' via ganeti-devel]

Namely, document that closing a handle/client is an idempotent
operation.

Signed-off-by: Petr Pudlak <pud...@google.com>
---
 src/Ganeti/UDSServer.hs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/Ganeti/UDSServer.hs b/src/Ganeti/UDSServer.hs
index df81bb8..041e738 100644
--- a/src/Ganeti/UDSServer.hs
+++ b/src/Ganeti/UDSServer.hs
@@ -175,6 +175,10 @@ openClientSocket tmo path = do
               S.connect sock (S.SockAddrUnix path)
   S.socketToHandle sock ReadWriteMode
 
+-- | Closes the handle.
+-- Performing the operation on a handle that has already been closed has no
+-- effect; doing so is not an error.
+-- All other operations on a closed handle will fail.
 closeClientSocket :: Handle -> IO ()
 closeClientSocket = hClose
 
@@ -250,6 +254,9 @@ acceptClient s = do
                 }
 
 -- | Closes the client socket.
+-- Performing the operation on a client that has already been closed has no
+-- effect; doing so is not an error.
+-- All other operations on a closed client will fail with an exception.
 closeClient :: Client -> IO ()
 closeClient client = do
   closeClientSocket . wsocket $ client
-- 
2.0.0.526.g5318336