git-annex/CmdLine/Action.hs
2024-06-25 14:54:20 -04:00

348 lines
11 KiB
Haskell

{- git-annex command-line actions and concurrency
-
- Copyright 2010-2021 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP, BangPatterns #-}
module CmdLine.Action where
import Annex.Common
import qualified Annex
import Annex.Concurrent
import Annex.WorkerPool
import Types.Command
import Types.Concurrency
import Annex.Content
import Messages.Concurrent
import Types.Messages
import Types.WorkerPool
import Types.ActionItem
import Remote.List
import Control.Concurrent
import Control.Concurrent.Async
import Control.Concurrent.STM
import GHC.Conc
import qualified Data.Map.Strict as M
import qualified System.Console.Regions as Regions
{- Runs a command, starting with the check stage, and then
- the seek stage. Finishes by running the continuation.
-
- Can exit when there was a problem or when a time or size limit was
- reached. Also shows a count of any failures when that is enabled.
-}
performCommandAction :: Bool -> Command -> CommandSeek -> Annex () -> Annex ()
performCommandAction canexit (Command { cmdcheck = c, cmdname = name }) seek cont = do
mapM_ runCheck c
Annex.changeState $ \s -> s { Annex.errcounter = 0 }
seek
finishCommandActions
cont
st <- Annex.getState id
when canexit $ liftIO $ case (Annex.errcounter st, Annex.reachedlimit st) of
(0, False) -> noop
(errcnt, False) -> do
showerrcount errcnt
exitWith $ ExitFailure 1
(0, True) -> exitreachedlimit
(errcnt, True) -> do
showerrcount errcnt
exitreachedlimit
where
showerrcount cnt = hPutStrLn stderr $
name ++ ": " ++ show cnt ++ " failed"
exitreachedlimit = exitWith $ ExitFailure 101
commandActions :: [CommandStart] -> Annex ()
commandActions = mapM_ commandAction
{- Runs one of the actions needed to perform a command.
- Individual actions can fail without stopping the whole command,
- including by throwing non-async exceptions.
-
- When concurrency is enabled, a thread is forked off to run the action
- in the background, as soon as a free worker slot is available.
- This should only be run in the seek stage.
-}
commandAction :: CommandStart -> Annex ()
commandAction start = do
st <- Annex.getState id
case getConcurrency' (Annex.concurrency st) of
NonConcurrent -> runnonconcurrent (Annex.sizelimit st)
Concurrent _ -> runconcurrent (Annex.sizelimit st) (Annex.workers st)
ConcurrentPerCpu -> runconcurrent (Annex.sizelimit st) (Annex.workers st)
where
runnonconcurrent sizelimit = start >>= \case
Nothing -> noop
Just (startmsg, perform) ->
checkSizeLimit sizelimit startmsg $ do
showStartMessage startmsg
void $ accountCommandAction startmsg $
performCommandAction' startmsg perform
runconcurrent sizelimit Nothing = runnonconcurrent sizelimit
runconcurrent sizelimit (Just tv) =
liftIO (atomically (waitStartWorkerSlot tv)) >>= maybe
(runnonconcurrent sizelimit)
(runconcurrent' sizelimit tv)
runconcurrent' sizelimit tv (workerstrd, workerstage) = do
aid <- liftIO $ async $ snd
<$> Annex.run workerstrd
(concurrentjob sizelimit (fst workerstrd))
liftIO $ atomically $ do
pool <- takeTMVar tv
let !pool' = addWorkerPool (ActiveWorker aid workerstage) pool
putTMVar tv pool'
void $ liftIO $ forkIO $ debugLocks $ do
-- accountCommandAction will usually catch
-- exceptions. Just in case, fall back to the
-- original workerstrd.
workerstrd' <- either (const workerstrd) id
<$> waitCatch aid
atomically $ do
pool <- takeTMVar tv
let !pool' = deactivateWorker pool aid workerstrd'
putTMVar tv pool'
concurrentjob sizelimit workerst = start >>= \case
Nothing -> noop
Just (startmsg, perform) ->
checkSizeLimit sizelimit startmsg $
concurrentjob' workerst startmsg perform
concurrentjob' workerst startmsg perform = case mkActionItem startmsg of
OnlyActionOn k _ -> ensureOnlyActionOn k $
-- If another job performed the same action while we
-- waited, there may be nothing left to do, so re-run
-- the start stage to see if it still wants to do
-- something.
start >>= \case
Just (startmsg', perform') ->
case mkActionItem startmsg' of
OnlyActionOn k' _ | k' /= k ->
concurrentjob' workerst startmsg' perform'
_ -> beginjob workerst startmsg' perform'
Nothing -> noop
_ -> beginjob workerst startmsg perform
beginjob workerst startmsg perform =
inOwnConsoleRegion (Annex.output workerst) $ do
enteringInitialStage
void $ accountCommandAction startmsg $
performconcurrent startmsg perform
-- Like performCommandAction' but the worker thread's stage
-- is changed before starting the cleanup action.
performconcurrent startmsg perform = do
showStartMessage startmsg
perform >>= \case
Just cleanup -> enteringStage CleanupStage $ do
r <- cleanup
showEndMessage startmsg r
return r
Nothing -> do
showEndMessage startmsg False
return False
{- Waits for all worker thrneads to finish and merges their AnnexStates
- back into the current Annex's state.
-}
finishCommandActions :: Annex ()
finishCommandActions = Annex.getState Annex.workers >>= \case
Nothing -> noop
Just tv -> do
Annex.changeState $ \s -> s { Annex.workers = Nothing }
vs <- liftIO $ atomically $ do
pool <- readTMVar tv
if allIdle pool
then return (spareVals pool)
else retry
mapM_ (mergeState . fst) vs
{- Waits for all worker threads that have been started so far to finish. -}
waitForAllRunningCommandActions :: Annex ()
waitForAllRunningCommandActions = Annex.getState Annex.workers >>= \case
Nothing -> noop
Just tv -> liftIO $ atomically $ do
pool <- readTMVar tv
unless (allIdle pool)
retry
{- Like commandAction, but without the concurrency. -}
includeCommandAction :: CommandStart -> CommandCleanup
includeCommandAction start =
start >>= \case
Nothing -> return True
Just (startmsg, perform) -> do
showStartMessage startmsg
accountCommandAction startmsg $
performCommandAction' startmsg perform
accountCommandAction :: StartMessage -> CommandCleanup -> CommandCleanup
accountCommandAction startmsg cleanup = tryNonAsync cleanup >>= \case
Right True -> return True
Right False -> incerr
Left err -> case fromException err of
Just exitcode -> liftIO $ exitWith exitcode
Nothing -> do
toplevelWarning True (UnquotedString (show err))
showEndMessage startmsg False
incerr
where
incerr = do
Annex.incError
return False
{- Runs a single command action through the start, perform and cleanup
- stages, without catching errors and without incrementing error counter.
- Useful if one command wants to run part of another command. -}
callCommandAction :: CommandStart -> CommandCleanup
callCommandAction start = start >>= \case
Just (startmsg, perform) -> do
showStartMessage startmsg
performCommandAction' startmsg perform
Nothing -> return True
performCommandAction' :: StartMessage -> CommandPerform -> CommandCleanup
performCommandAction' startmsg perform =
perform >>= \case
Nothing -> do
showEndMessage startmsg False
return False
Just cleanup -> do
r <- cleanup
showEndMessage startmsg r
return r
{- Start concurrency when that has been requested.
- Should be run wrapping the seek stage of a command.
-
- Note that a duplicate of the Annex state is made here, and worker
- threads use that state. While the worker threads are not actually
- started here, that has the same effect.
-}
startConcurrency :: UsedStages -> Annex a -> Annex a
startConcurrency usedstages a = do
fromcmdline <- getConcurrency
fromgitcfg <- annexJobs <$> Annex.getGitConfig
let usegitcfg = setConcurrency (ConcurrencyGitConfig fromgitcfg)
case (fromcmdline, fromgitcfg) of
(NonConcurrent, NonConcurrent) -> a
(Concurrent n, _)
| n > 1 -> goconcurrent n
| otherwise -> do
setConcurrency' NonConcurrent ConcurrencyCmdLine
a
(ConcurrentPerCpu, _) ->
goconcurrentpercpu
(NonConcurrent, Concurrent n) -> do
usegitcfg
goconcurrent n
(NonConcurrent, ConcurrentPerCpu) -> do
usegitcfg
goconcurrentpercpu
where
goconcurrent n = do
raisecapabilitiesto n
withMessageState $ \s -> case outputType s of
NormalOutput -> ifM (liftIO concurrentOutputSupported)
( Regions.displayConsoleRegions $
goconcurrent' n True
, goconcurrent' n False
)
_ -> goconcurrent' n False
goconcurrent' n b = bracket_ (setup n b) cleanup a
goconcurrentpercpu = goconcurrent =<< liftIO getNumProcessors
setup n b = do
setconcurrentoutputenabled b
initworkerpool n
cleanup = do
finishCommandActions
setconcurrentoutputenabled False
setconcurrentoutputenabled b = Annex.changeState $ \s ->
s { Annex.output = (Annex.output s) { concurrentOutputEnabled = b } }
raisecapabilitiesto n = do
c <- liftIO getNumCapabilities
when (n > c) $
liftIO $ setNumCapabilities n
initworkerpool n = do
tv <- liftIO newEmptyTMVarIO
Annex.changeState $ \s -> s { Annex.workers = Just tv }
prepDupState
st <- dupState
rd <- Annex.getRead id
liftIO $ atomically $ putTMVar tv $
allocateWorkerPool (st, rd) (max n 1) usedstages
-- Make sure that some expensive actions have been done before
-- starting threads. This way the state has them already run,
-- and each thread won't try to do them.
prepDupState :: Annex ()
prepDupState = do
_ <- remoteList
return ()
{- Ensures that only one thread processes a key at a time.
- Other threads will block until it's done.
-
- May be called repeatedly by the same thread without blocking. -}
ensureOnlyActionOn :: Key -> Annex a -> Annex a
ensureOnlyActionOn k a = debugLocks $
go =<< getConcurrency
where
go NonConcurrent = a
go (Concurrent _) = goconcurrent
go ConcurrentPerCpu = goconcurrent
goconcurrent = do
tv <- Annex.getRead Annex.activekeys
bracket (setup tv) id (const a)
setup tv = liftIO $ do
mytid <- myThreadId
atomically $ do
m <- readTVar tv
case M.lookup k m of
Just tid
| tid /= mytid -> retry
| otherwise -> return $ return ()
Nothing -> do
writeTVar tv $! M.insert k mytid m
return $ liftIO $ atomically $
modifyTVar tv $ M.delete k
checkSizeLimit :: Maybe (TVar Integer) -> StartMessage -> Annex () -> Annex ()
checkSizeLimit Nothing _ a = a
checkSizeLimit (Just sizelimitvar) startmsg a =
case actionItemKey (mkActionItem startmsg) of
Just k -> case fromKey keySize k of
Just sz -> go sz
Nothing -> do
fsz <- catchMaybeIO $ withObjectLoc k $
liftIO . getFileSize
maybe reachedlimit go fsz
Nothing -> a
where
go sz = do
fits <- liftIO $ atomically $ do
n <- readTVar sizelimitvar
let !n' = n - sz
if n' >= 0
then do
writeTVar sizelimitvar n'
return True
else return False
if fits
then a
else reachedlimit
reachedlimit = Annex.changeState $ \s -> s { Annex.reachedlimit = True }