assistant: When autostarted, wait 5 seconds before running the startup scan, to avoid contending with the user's desktop login process.

Assistant.hs

@@ -48,6 +48,7 @@ import Assistant.Types.UrlRenderer
 import qualified Utility.Daemon
 import Utility.LogFile
 import Utility.ThreadScheduler
+import Utility.HumanTime
 import qualified Build.SysConfig as SysConfig
 
 import System.Log.Logger
@@ -61,8 +62,8 @@ stopDaemon = liftIO . Utility.Daemon.stopDaemon =<< fromRepo gitAnnexPidFile
  -
  - startbrowser is passed the url and html shim file, as well as the original
  - stdout and stderr descriptors. -}
-startDaemon :: Bool -> Bool -> Maybe HostName ->  Maybe (Maybe Handle -> Maybe Handle -> String -> FilePath -> IO ()) -> Annex ()
-startDaemon assistant foreground listenhost startbrowser = do
+startDaemon :: Bool -> Bool -> Maybe Duration -> Maybe HostName ->  Maybe (Maybe Handle -> Maybe Handle -> String -> FilePath -> IO ()) -> Annex ()
+startDaemon assistant foreground startdelay listenhost startbrowser = do
 	Annex.changeState $ \s -> s { Annex.daemon = True }
 	pidfile <- fromRepo gitAnnexPidFile
 	logfile <- fromRepo gitAnnexLogFile
@@ -140,7 +141,7 @@ startDaemon assistant foreground listenhost startbrowser = do
 			, watch $ watchThread
 			-- must come last so that all threads that wait
 			-- on it have already started waiting
-			, watch $ sanityCheckerStartupThread
+			, watch $ sanityCheckerStartupThread startdelay
 			]
 	
 		liftIO waitForTermination

Assistant/Threads/SanityChecker.hs

@@ -25,15 +25,22 @@ import Utility.NotificationBroadcaster
 import Config
 import qualified Git
 import qualified Utility.Lsof as Lsof
+import Utility.HumanTime
 
 import Data.Time.Clock.POSIX
 
 {- This thread runs once at startup, and most other threads wait for it
  - to finish. (However, the webapp thread does not, to prevent the UI
  - being nonresponsive.) -}
-sanityCheckerStartupThread :: NamedThread
-sanityCheckerStartupThread = namedThreadUnchecked "SanityCheckerStartup" $
-	startupCheck
+sanityCheckerStartupThread :: Maybe Duration -> NamedThread
+sanityCheckerStartupThread startupdelay = namedThreadUnchecked "SanityCheckerStartup" $ do
+	checkStaleGitLocks
+
+	liftIO $ maybe noop (threadDelaySeconds . Seconds . fromIntegral . durationSeconds) startupdelay
+
+	{- Notify other threads that the startup sanity check is done. -}
+	status <- getDaemonStatus
+	liftIO $ sendNotification $ startupSanityCheckNotifier status
 
 {- This thread wakes up hourly for inxepensive frequent sanity checks. -}
 sanityCheckerHourlyThread :: NamedThread
@@ -80,14 +87,6 @@ waitForNextCheck = do
 			oneDay - truncate (now - lastcheck)
 		| otherwise = oneDay
 
-startupCheck :: Assistant ()
-startupCheck = do
-	checkStaleGitLocks
-
-	{- Notify other threads that the startup sanity check is done. -}
-	status <- getDaemonStatus
-	liftIO $ sendNotification $ startupSanityCheckNotifier status
-
 {- It's important to stay out of the Annex monad as much as possible while
  - running potentially expensive parts of this check, since remaining in it
  - will block the watcher. -}

Command/Assistant.hs

@@ -14,43 +14,55 @@ import qualified Command.Watch
 import Init
 import Config.Files
 import qualified Build.SysConfig
+import Utility.HumanTime
 
 import System.Environment
 
 def :: [Command]
-def = [noRepo checkAutoStart $ dontCheck repoExists $
-	withOptions [Command.Watch.foregroundOption, Command.Watch.stopOption, autoStartOption] $ 
+def = [noRepo checkAutoStart $ dontCheck repoExists $ withOptions options $
 	command "assistant" paramNothing seek SectionCommon
 		"automatically handle changes"]
 
+options :: [Option]
+options =
+	[ Command.Watch.foregroundOption
+	, Command.Watch.stopOption
+	, autoStartOption
+	, startDelayOption
+	]
+
 autoStartOption :: Option
 autoStartOption = Option.flag [] "autostart" "start in known repositories"
 
+startDelayOption :: Option
+startDelayOption = Option.field [] "startdelay" paramNumber "delay before running startup scan"
+
 seek :: [CommandSeek]
 seek = [withFlag Command.Watch.stopOption $ \stopdaemon ->
 	withFlag Command.Watch.foregroundOption $ \foreground ->
 	withFlag autoStartOption $ \autostart ->
-	withNothing $ start foreground stopdaemon autostart]
+	withField startDelayOption (pure . maybe Nothing parseDuration) $ \startdelay -> 
+	withNothing $ start foreground stopdaemon autostart startdelay]
 
-start :: Bool -> Bool -> Bool -> CommandStart
-start foreground stopdaemon autostart
+start :: Bool -> Bool -> Bool -> Maybe Duration -> CommandStart
+start foreground stopdaemon autostart startdelay
 	| autostart = do
-		liftIO autoStart
+		liftIO $ autoStart startdelay
 		stop
 	| otherwise = do
 		ensureInitialized
-		Command.Watch.start True foreground stopdaemon
+		Command.Watch.start True foreground stopdaemon startdelay
 
 {- Run outside a git repository. Check to see if any parameter is
  - --autostart and enter autostart mode. -}
 checkAutoStart :: IO ()
 checkAutoStart = ifM (elem "--autostart" <$> getArgs)
-	( autoStart
+	( autoStart Nothing
 	, error "Not in a git repository."
 	) 
 
-autoStart :: IO ()
-autoStart = do
+autoStart :: Maybe Duration -> IO ()
+autoStart startdelay = do
 	dirs <- liftIO readAutoStartFile
 	when (null dirs) $ do
 		f <- autoStartFile
@@ -67,5 +79,10 @@ autoStart = do
 	go haveionice program dir = do
 		setCurrentDirectory dir
 		if haveionice
-			then boolSystem "ionice" [Param "-c3", Param program, Param "assistant"]
-			else boolSystem program [Param "assistant"]
+			then boolSystem "ionice" (Param "-c3" : Param program : baseparams)
+			else boolSystem program baseparams
+	  where
+		baseparams =
+			[ Param "assistant"
+			, Param $ "--startdelay=" ++ fromDuration (fromMaybe (Duration 5) startdelay)
+			]

Command/Watch.hs

@@ -11,6 +11,7 @@ import Common.Annex
 import Assistant
 import Command
 import Option
+import Utility.HumanTime
 
 def :: [Command]
 def = [notBareRepo $ withOptions [foregroundOption, stopOption] $ 
@@ -19,7 +20,7 @@ def = [notBareRepo $ withOptions [foregroundOption, stopOption] $
 seek :: [CommandSeek]
 seek = [withFlag stopOption $ \stopdaemon -> 
 	withFlag foregroundOption $ \foreground ->
-	withNothing $ start False foreground stopdaemon]
+	withNothing $ start False foreground stopdaemon Nothing]
 
 foregroundOption :: Option
 foregroundOption = Option.flag [] "foreground" "do not daemonize"
@@ -27,9 +28,9 @@ foregroundOption = Option.flag [] "foreground" "do not daemonize"
 stopOption :: Option
 stopOption = Option.flag [] "stop" "stop daemon"
 
-start :: Bool -> Bool -> Bool -> CommandStart
-start assistant foreground stopdaemon = do
+start :: Bool -> Bool -> Bool -> Maybe Duration -> CommandStart
+start assistant foreground stopdaemon startdelay = do
 	if stopdaemon
 		then stopDaemon
-		else startDaemon assistant foreground Nothing Nothing -- does not return
+		else startDaemon assistant foreground startdelay Nothing Nothing -- does not return
 	stop

Command/WebApp.hs

@@ -69,7 +69,7 @@ start' allowauto listenhost = do
 					url <- liftIO . readFile
 						=<< fromRepo gitAnnexUrlFile
 					liftIO $ openBrowser browser f url Nothing Nothing
-			, startDaemon True True listenhost $ Just $ 
+			, startDaemon True True Nothing listenhost $ Just $ 
 				\origout origerr url htmlshim ->
 					if isJust listenhost
 						then maybe noop (`hPutStrLn` url) origout
@@ -155,7 +155,7 @@ firstRun listenhost = do
 			_wait <- takeMVar v
 			state <- Annex.new =<< Git.CurrentRepo.get
 			Annex.eval state $
-				startDaemon True True listenhost $ Just $
+				startDaemon True True Nothing listenhost $ Just $
 					sendurlback v
 	sendurlback v _origout _origerr url _htmlshim = do
 		recordUrl url

debian/changelog

@@ -1,3 +1,10 @@
+git-annex (4.20131025) UNRELEASED; urgency=low
+
+  * assistant: When autostarted, wait 5 seconds before running the startup
+    scan, to avoid contending with the user's desktop login process.
+
+ -- Joey Hess <joeyh@debian.org>  Sat, 26 Oct 2013 12:11:48 -0400
+
 git-annex (4.20131024) unstable; urgency=low
 
   * webapp: Fix bug when adding a remote and git-remote-gcrypt

doc/bugs/Too_much_system_load_on_startup.mdwn

@@ -18,3 +18,7 @@ to
 Exec=sleep 5 ionice -c 3 /usr/bin/git-annex assistant --autostart
 
 This delays the start of git-annex for 5 seconds, letting the desktop get started, and forces git-annex to yield IO to other programs -preventing it from slowing them down by forcing them to wait for disk access. Since this is a background daemon with potentially high IO usage, but no need for quick responsiveness, perhaps that would make a decent default?
+
+> Added 5 second delay to existing ionice. Provisionally [[done]],
+> although it does occur to me that the startup scan could add some delays
+> in between actions to run more as a batch job. --[[Joey]]