72e5764a87
This old code will now be useful for git-annex beyond the assistant. git-annex won't use the CheckTransferrer part, and won't run transferkeys as a batch process, and will want withTransferrer to not shut down transferkeys processes. Still, the rest of this is a good fit for what I need now. Also removed some dead code, and simplified a little bit. This commit was sponsored by Mark Reidenbach on Patreon.
87 lines
2.4 KiB
Haskell
87 lines
2.4 KiB
Haskell
{- Running a long or expensive batch operation niced.
|
|
-
|
|
- Copyright 2013-2020 Joey Hess <id@joeyh.name>
|
|
-
|
|
- License: BSD-2-clause
|
|
-}
|
|
|
|
{-# LANGUAGE CPP #-}
|
|
|
|
module Utility.Batch (
|
|
batch,
|
|
BatchCommandMaker,
|
|
nonBatchCommandMaker,
|
|
getBatchCommandMaker,
|
|
toBatchCommand,
|
|
batchCommand,
|
|
batchCommandEnv,
|
|
) where
|
|
|
|
import Common
|
|
|
|
#if defined(linux_HOST_OS)
|
|
import Control.Concurrent.Async
|
|
import System.Posix.Process
|
|
#endif
|
|
|
|
{- Runs an operation, at batch priority.
|
|
-
|
|
- This is done by running it in a bound thread, which on Linux can be set
|
|
- to have a different nice level than the rest of the program. Note that
|
|
- due to running in a bound thread, some operations may be more expensive
|
|
- to perform. Also note that if the action calls forkIO or forkOS itself,
|
|
- that will make a new thread that does not have the batch priority.
|
|
-
|
|
- POSIX threads do not support separate nice levels, so on other operating
|
|
- systems, the action is simply ran.
|
|
-}
|
|
batch :: IO a -> IO a
|
|
#if defined(linux_HOST_OS)
|
|
batch a = wait =<< batchthread
|
|
where
|
|
batchthread = asyncBound $ do
|
|
setProcessPriority 0 maxNice
|
|
a
|
|
maxNice = 19
|
|
#else
|
|
batch a = a
|
|
#endif
|
|
|
|
{- Makes a command be run by whichever of nice, ionice, and nocache
|
|
- are available in the path. -}
|
|
type BatchCommandMaker = (String, [CommandParam]) -> (String, [CommandParam])
|
|
|
|
nonBatchCommandMaker :: BatchCommandMaker
|
|
nonBatchCommandMaker = id
|
|
|
|
getBatchCommandMaker :: IO BatchCommandMaker
|
|
getBatchCommandMaker = do
|
|
#ifndef mingw32_HOST_OS
|
|
nicers <- filterM (inPath . fst)
|
|
[ ("nice", [])
|
|
, ("ionice", ["-c3"])
|
|
, ("nocache", [])
|
|
]
|
|
return $ \(command, params) ->
|
|
case nicers of
|
|
[] -> (command, params)
|
|
(first:rest) -> (fst first, map Param (snd first ++ concatMap (\p -> fst p : snd p) rest ++ [command]) ++ params)
|
|
#else
|
|
return id
|
|
#endif
|
|
|
|
toBatchCommand :: (String, [CommandParam]) -> IO (String, [CommandParam])
|
|
toBatchCommand v = do
|
|
batchmaker <- getBatchCommandMaker
|
|
return $ batchmaker v
|
|
|
|
{- Runs a command in a way that's suitable for batch jobs that can be
|
|
- interrupted. -}
|
|
batchCommand :: String -> [CommandParam] -> IO Bool
|
|
batchCommand command params = batchCommandEnv command params Nothing
|
|
|
|
batchCommandEnv :: String -> [CommandParam] -> Maybe [(String, String)] -> IO Bool
|
|
batchCommandEnv command params environ = do
|
|
batchmaker <- getBatchCommandMaker
|
|
let (command', params') = batchmaker (command, params)
|
|
boolSystemEnv command' params' environ
|