Hbal.hs: rename functions that deal with early termination

In Hbal.hs, it's easy to get lost in the flow of exec* functions
because their names are similar and don't convey their different
purposes (e.g. runJobSet, execJobSet, execWrapper).

This patch renames 'runJobSet' to 'execWithCancel', and 'execWrapper'
to 'execCancelWrapper', since these two functions deal, in particular,
with early termination when the user presses ^C.

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

htools/Ganeti/HTools/Program/Hbal.hs

@@ -192,11 +192,11 @@ waitForJobs client jids = do
 checkJobsStatus :: [JobStatus] -> Bool
 checkJobsStatus = all (== JOB_STATUS_SUCCESS)
 
--- | Wrapper over execJobSet checking for early termination.
-execWrapper :: String -> Node.List
-            -> Instance.List -> IORef Int -> [JobSet] -> IO Bool
-execWrapper _      _  _  _    [] = return True
-execWrapper master nl il cref alljss = do
+-- | Wrapper over execJobSet checking for early termination via an IORef.
+execCancelWrapper :: String -> Node.List
+                  -> Instance.List -> IORef Int -> [JobSet] -> IO Bool
+execCancelWrapper _      _  _  _    [] = return True
+execCancelWrapper master nl il cref alljss = do
   cancel <- readIORef cref
   if cancel > 0
     then do
@@ -231,7 +231,7 @@ execJobSet master nl il cref (js:jss) = do
       hPutStrLn stderr x
       return False
     Ok x -> if checkJobsStatus x
-              then execWrapper master nl il cref jss
+              then execCancelWrapper master nl il cref jss
               else do
                 hPutStrLn stderr $ "Not all jobs completed successfully: " ++
                           show x
@@ -251,7 +251,7 @@ maybeExecJobs opts ord_plc fin_nl il cmd_jobs =
             Nothing -> do
               hPutStrLn stderr "Execution of commands possible only on LUXI"
               return False
-            Just master -> runJobSet master fin_nl il cmd_jobs)
+            Just master -> execWithCancel master fin_nl il cmd_jobs)
     else return True
 
 -- | Signal handler for graceful termination.
@@ -269,13 +269,14 @@ handleSigTerm cref = do
   putStrLn "Double cancel request, exiting now..."
   exitImmediately $ ExitFailure 2
 
--- | Runs a job set with handling of signals.
-runJobSet :: String -> Node.List -> Instance.List -> [JobSet] -> IO Bool
-runJobSet master fin_nl il cmd_jobs = do
+-- | Prepares to run a set of jobsets with handling of signals and early
+-- termination.
+execWithCancel :: String -> Node.List -> Instance.List -> [JobSet] -> IO Bool
+execWithCancel master fin_nl il cmd_jobs = do
   cref <- newIORef 0
   mapM_ (\(hnd, sig) -> installHandler sig (Catch (hnd cref)) Nothing)
     [(handleSigTerm, softwareTermination), (handleSigInt, keyboardSignal)]
-  execWrapper master fin_nl il cref cmd_jobs
+  execCancelWrapper master fin_nl il cref cmd_jobs
 
 -- | Select the target node group.
 selectGroup :: Options -> Group.List -> Node.List -> Instance.List