git-annex/Assistant/NamedThread.hs
Joey Hess 40ecf58d4b
update licenses from GPL to AGPL
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.

Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.

(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
2019-03-13 15:48:14 -04:00

99 lines
3 KiB
Haskell

{- git-annex assistant named threads.
-
- Copyright 2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL 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