git-annex/Assistant/NamedThread.hs
Joey Hess 256d8f07e8
avoid insertWith' depreaction warning
Switch to Data.Map.Strict everywhere that used it.

There are still lots of lazy maps in git-annex. I think switching these
is safe. The risk is that there might be a map that is used in a way
that relies on the values not being evaluated to WHNF, and switching to
strict might result in bad performance or memory use. So, I have not
switched everything.
2018-04-22 13:28:31 -04:00

99 lines
3 KiB
Haskell

{- git-annex assistant named threads.
-
- Copyright 2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Assistant.NamedThread where
import Annex.Common
import Assistant.Types.NamedThread
import Assistant.Types.ThreadName
import Assistant.Types.DaemonStatus
import Assistant.Types.UrlRenderer
import Assistant.DaemonStatus
import Assistant.Monad
import Utility.NotificationBroadcaster
import Control.Concurrent
import Control.Concurrent.Async
import qualified Data.Map.Strict as M
import qualified Control.Exception as E
#ifdef WITH_WEBAPP
import Assistant.WebApp.Types
import Assistant.Types.Alert
import Assistant.Alert
import qualified Data.Text as T
#endif
{- Starts a named thread, if it's not already running.
-
- Named threads are run by a management thread, so if they crash
- an alert is displayed, allowing the thread to be restarted. -}
startNamedThread :: UrlRenderer -> NamedThread -> Assistant ()
startNamedThread urlrenderer (NamedThread afterstartupsanitycheck name a) =
M.lookup name . startedThreads <$> getDaemonStatus >>= \case
Nothing -> start
Just (aid, _) -> do
r <- liftIO (E.try (poll aid) :: IO (Either E.SomeException (Maybe (Either E.SomeException ()))))
case r of
Right Nothing -> noop
_ -> start
where
start
| afterstartupsanitycheck = do
status <- getDaemonStatus
h <- liftIO $ newNotificationHandle False $
startupSanityCheckNotifier status
startwith $ runmanaged $
liftIO $ waitNotification h
| otherwise = startwith $ runmanaged noop
startwith runner = do
d <- getAssistant id
aid <- liftIO $ runner $ d { threadName = name }
restart <- asIO $ startNamedThread urlrenderer (NamedThread False name a)
modifyDaemonStatus_ $ \s -> s
{ startedThreads = M.insert name (aid, restart) (startedThreads s) }
runmanaged first d = do
aid <- async $ runAssistant d $ do
void first
a
void $ forkIO $ manager d aid
return aid
manager d aid = (E.try (wait aid) :: IO (Either E.SomeException ())) >>= \case
Right _ -> noop
Left e -> do
let msg = unwords
[ fromThreadName $ threadName d
, "crashed:", show e
]
hPutStrLn stderr msg
#ifdef WITH_WEBAPP
button <- runAssistant d $ mkAlertButton True
(T.pack "Restart Thread")
urlrenderer
(RestartThreadR name)
runAssistant d $ void $ addAlert $
(warningAlert (fromThreadName name) msg)
{ alertButtons = [button] }
#endif
namedThreadId :: NamedThread -> Assistant (Maybe ThreadId)
namedThreadId (NamedThread _ name _) = do
m <- startedThreads <$> getDaemonStatus
return $ asyncThreadId . fst <$> M.lookup name m
{- Waits for all named threads that have been started to finish.
-
- Note that if a named thread crashes, it will probably
- cause this to crash as well. Also, named threads that are started
- after this is called will not be waited on. -}
waitNamedThreads :: Assistant ()
waitNamedThreads = do
m <- startedThreads <$> getDaemonStatus
liftIO $ mapM_ (wait . fst) $ M.elems m