git-annex/Assistant.hs
Joey Hess 947d2a10bc
assistant: Fix a crash on startup by avoiding using forkProcess
ghc 8.8.4 seems to have changed something that broke code that has been
successfully using forkProcess since 2012. Likely a change to GC internals.

Since forkProcess has never had clear documentation about how to
use it safely, avoid using it at all. Instead, when git-annex needs to
daemonize itself, re-run the git-annex command, in a new process group
and session.

This commit was sponsored by Luke Shumaker on Patreon.
2021-05-12 15:08:03 -04:00

194 lines
6 KiB
Haskell

{- git-annex assistant daemon
-
- Copyright 2012-2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
module Assistant where
import qualified Annex
import Assistant.Common
import Assistant.DaemonStatus
import Assistant.NamedThread
import Assistant.Types.ThreadedMonad
import Assistant.Threads.DaemonStatus
import Assistant.Threads.Watcher
import Assistant.Threads.Committer
import Assistant.Threads.Pusher
import Assistant.Threads.Exporter
import Assistant.Threads.Merger
import Assistant.Threads.TransferWatcher
import Assistant.Threads.Transferrer
import Assistant.Threads.RemoteControl
import Assistant.Threads.SanityChecker
import Assistant.Threads.Cronner
import Assistant.Threads.ProblemFixer
#ifndef mingw32_HOST_OS
import Assistant.Threads.MountWatcher
#endif
import Assistant.Threads.NetWatcher
import Assistant.Threads.Upgrader
import Assistant.Threads.UpgradeWatcher
import Assistant.Threads.TransferScanner
import Assistant.Threads.TransferPoller
import Assistant.Threads.ConfigMonitor
import Assistant.Threads.Glacier
#ifdef WITH_WEBAPP
import Assistant.WebApp
import Assistant.Threads.WebApp
#ifdef WITH_PAIRING
import Assistant.Threads.PairListener
#endif
#else
import Assistant.Types.UrlRenderer
#endif
import qualified Utility.Daemon
import Utility.ThreadScheduler
import Utility.HumanTime
import Annex.Perms
import Annex.BranchState
import Utility.LogFile
import Annex.Path
#ifdef mingw32_HOST_OS
import Utility.Env
import System.Environment (getArgs)
#endif
import qualified Utility.Debug as Debug
import Network.Socket (HostName)
stopDaemon :: Annex ()
stopDaemon = liftIO . Utility.Daemon.stopDaemon . fromRawFilePath
=<< fromRepo gitAnnexPidFile
{- Starts the daemon. If the daemon is run in the foreground, once it's
- running, can start the browser.
-
- startbrowser is passed the url and html shim file, as well as the original
- stdout and stderr descriptors. -}
startDaemon :: Bool -> Bool -> Maybe Duration -> Maybe String -> Maybe HostName -> Maybe (Maybe Handle -> Maybe Handle -> String -> FilePath -> IO ()) -> Annex ()
startDaemon assistant foreground startdelay cannotrun listenhost startbrowser = do
Annex.changeState $ \s -> s { Annex.daemon = True }
enableInteractiveBranchAccess
pidfile <- fromRepo gitAnnexPidFile
logfile <- fromRepo gitAnnexDaemonLogFile
liftIO $ Debug.debug "Assistant" $ "logging to " ++ fromRawFilePath logfile
createAnnexDirectory (parentDir pidfile)
#ifndef mingw32_HOST_OS
createAnnexDirectory (parentDir logfile)
let logfd = handleToFd =<< openLog (fromRawFilePath logfile)
if foreground
then do
origout <- liftIO $ catchMaybeIO $
fdToHandle =<< dup stdOutput
origerr <- liftIO $ catchMaybeIO $
fdToHandle =<< dup stdError
let undaemonize = Utility.Daemon.foreground logfd (Just (fromRawFilePath pidfile))
start undaemonize $
case startbrowser of
Nothing -> Nothing
Just a -> Just $ a origout origerr
else do
git_annex <- liftIO programPath
ps <- gitAnnexDaemonizeParams
start (Utility.Daemon.daemonize git_annex ps logfd (Just (fromRawFilePath pidfile)) False) Nothing
#else
-- Windows doesn't daemonize, but does redirect output to the
-- log file. The only way to do so is to restart the program.
when (foreground || not foreground) $ do
let flag = "GIT_ANNEX_OUTPUT_REDIR"
createAnnexDirectory (parentDir logfile)
ifM (liftIO $ isNothing <$> getEnv flag)
( liftIO $ withNullHandle $ \nullh -> do
loghandle <- openLog (fromRawFilePath logfile)
e <- getEnvironment
cmd <- programPath
ps <- getArgs
let p = (proc cmd ps)
{ env = Just (addEntry flag "1" e)
, std_in = UseHandle nullh
, std_out = UseHandle loghandle
, std_err = UseHandle loghandle
}
exitcode <- withCreateProcess p $ \_ _ _ pid ->
waitForProcess pid
exitWith exitcode
, start (Utility.Daemon.foreground (Just (fromRawFilePath pidfile))) $
case startbrowser of
Nothing -> Nothing
Just a -> Just $ a Nothing Nothing
)
#endif
where
start daemonize webappwaiter = withThreadState $ \st -> do
checkCanWatch
dstatus <- startDaemonStatus
logfile <- fromRepo gitAnnexDaemonLogFile
liftIO $ Debug.debug "Assistant" $ "logging to " ++ fromRawFilePath logfile
liftIO $ daemonize $
flip runAssistant (go webappwaiter)
=<< newAssistantData st dstatus
#ifdef WITH_WEBAPP
go webappwaiter = do
d <- getAssistant id
#else
go _webappwaiter = do
#endif
urlrenderer <- liftIO newUrlRenderer
#ifdef WITH_WEBAPP
let webappthread = [ assist $ webAppThread d urlrenderer False cannotrun Nothing listenhost webappwaiter ]
#else
let webappthread = []
#endif
let threads = if isJust cannotrun
then webappthread
else webappthread ++
[ watch commitThread
#ifdef WITH_WEBAPP
#ifdef WITH_PAIRING
, assist $ pairListenerThread urlrenderer
#endif
#endif
, assist pushThread
, assist pushRetryThread
, assist exportThread
, assist exportRetryThread
, assist mergeThread
, assist transferWatcherThread
, assist transferPollerThread
, assist transfererThread
, assist remoteControlThread
, assist daemonStatusThread
, assist $ sanityCheckerDailyThread urlrenderer
, assist sanityCheckerHourlyThread
, assist $ problemFixerThread urlrenderer
#ifndef mingw32_HOST_OS
, assist $ mountWatcherThread urlrenderer
#endif
, assist netWatcherThread
, assist $ upgraderThread urlrenderer
, assist $ upgradeWatcherThread urlrenderer
, assist netWatcherFallbackThread
, assist $ transferScannerThread urlrenderer
, assist $ cronnerThread urlrenderer
, assist configMonitorThread
, assist glacierThread
, watch watchThread
-- must come last so that all threads that wait
-- on it have already started waiting
, watch $ sanityCheckerStartupThread startdelay
]
mapM_ (startthread urlrenderer) threads
liftIO waitForTermination
watch a = (True, a)
assist a = (False, a)
startthread urlrenderer (watcher, t)
| watcher || assistant = startNamedThread urlrenderer t
| otherwise = noop