{-# LANGUAGE FlexibleContexts #-}
module Distribution.Client.JobControl (
JobControl,
newSerialJobControl,
newParallelJobControl,
spawnJob,
collectJob,
remainingJobs,
cancelJobs,
JobLimit,
newJobLimit,
withJobLimit,
Lock,
newLock,
criticalSection
) where
import Distribution.Client.Compat.Prelude
import Prelude ()
import Control.Monad (forever, replicateM_)
import Control.Concurrent (forkIO)
import Control.Concurrent.MVar
import Control.Concurrent.STM (STM, atomically)
import Control.Concurrent.STM.TVar
import Control.Concurrent.STM.TChan
import Control.Exception (bracket_, try)
import Distribution.Compat.Stack
import Distribution.Client.Compat.Semaphore
data JobControl m a = JobControl {
forall (m :: * -> *) a. JobControl m a -> m a -> m ()
spawnJob :: m a -> m (),
forall (m :: * -> *) a. JobControl m a -> m a
collectJob :: m a,
forall (m :: * -> *) a. JobControl m a -> m Bool
remainingJobs :: m Bool,
forall (m :: * -> *) a. JobControl m a -> m ()
cancelJobs :: m ()
}
newSerialJobControl :: IO (JobControl IO a)
newSerialJobControl :: forall a. IO (JobControl IO a)
newSerialJobControl = do
TChan (IO a)
qVar <- forall a. IO (TChan a)
newTChanIO
forall (m :: * -> *) a. Monad m => a -> m a
return JobControl {
spawnJob :: IO a -> IO ()
spawnJob = forall a. TChan (IO a) -> IO a -> IO ()
spawn TChan (IO a)
qVar,
collectJob :: IO a
collectJob = forall a. TChan (IO a) -> IO a
collect TChan (IO a)
qVar,
remainingJobs :: IO Bool
remainingJobs = forall a. TChan (IO a) -> IO Bool
remaining TChan (IO a)
qVar,
cancelJobs :: IO ()
cancelJobs = forall a. TChan (IO a) -> IO ()
cancel TChan (IO a)
qVar
}
where
spawn :: TChan (IO a) -> IO a -> IO ()
spawn :: forall a. TChan (IO a) -> IO a -> IO ()
spawn TChan (IO a)
qVar IO a
job = forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TChan a -> a -> STM ()
writeTChan TChan (IO a)
qVar IO a
job
collect :: TChan (IO a) -> IO a
collect :: forall a. TChan (IO a) -> IO a
collect TChan (IO a)
qVar =
forall (m :: * -> *) a. Monad m => m (m a) -> m a
join forall a b. (a -> b) -> a -> b
$ forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TChan a -> STM a
readTChan TChan (IO a)
qVar
remaining :: TChan (IO a) -> IO Bool
remaining :: forall a. TChan (IO a) -> IO Bool
remaining TChan (IO a)
qVar = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap Bool -> Bool
not forall a b. (a -> b) -> a -> b
$ forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TChan a -> STM Bool
isEmptyTChan TChan (IO a)
qVar
cancel :: TChan (IO a) -> IO ()
cancel :: forall a. TChan (IO a) -> IO ()
cancel TChan (IO a)
qVar = do
[IO a]
_ <- forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TChan a -> STM [a]
readAllTChan TChan (IO a)
qVar
forall (m :: * -> *) a. Monad m => a -> m a
return ()
newParallelJobControl :: WithCallStack (Int -> IO (JobControl IO a))
newParallelJobControl :: forall a. WithCallStack (Int -> IO (JobControl IO a))
newParallelJobControl Int
n | Int
n forall a. Ord a => a -> a -> Bool
< Int
1 Bool -> Bool -> Bool
|| Int
n forall a. Ord a => a -> a -> Bool
> Int
1000 =
forall a. HasCallStack => [Char] -> a
error forall a b. (a -> b) -> a -> b
$ [Char]
"newParallelJobControl: not a sensible number of jobs: " forall a. [a] -> [a] -> [a]
++ forall a. Show a => a -> [Char]
show Int
n
newParallelJobControl Int
maxJobLimit = do
TChan (IO a)
inqVar <- forall a. IO (TChan a)
newTChanIO
TChan (Either SomeException a)
outqVar <- forall a. IO (TChan a)
newTChanIO
TVar Int
countVar <- forall a. a -> IO (TVar a)
newTVarIO Int
0
forall (m :: * -> *) a. Applicative m => Int -> m a -> m ()
replicateM_ Int
maxJobLimit forall a b. (a -> b) -> a -> b
$
IO () -> IO ThreadId
forkIO forall a b. (a -> b) -> a -> b
$
forall a. TChan (IO a) -> TChan (Either SomeException a) -> IO ()
worker TChan (IO a)
inqVar TChan (Either SomeException a)
outqVar
forall (m :: * -> *) a. Monad m => a -> m a
return JobControl {
spawnJob :: IO a -> IO ()
spawnJob = forall a. TChan (IO a) -> TVar Int -> IO a -> IO ()
spawn TChan (IO a)
inqVar TVar Int
countVar,
collectJob :: IO a
collectJob = forall a. TChan (Either SomeException a) -> TVar Int -> IO a
collect TChan (Either SomeException a)
outqVar TVar Int
countVar,
remainingJobs :: IO Bool
remainingJobs = TVar Int -> IO Bool
remaining TVar Int
countVar,
cancelJobs :: IO ()
cancelJobs = forall a. TChan (IO a) -> TVar Int -> IO ()
cancel TChan (IO a)
inqVar TVar Int
countVar
}
where
worker :: TChan (IO a) -> TChan (Either SomeException a) -> IO ()
worker :: forall a. TChan (IO a) -> TChan (Either SomeException a) -> IO ()
worker TChan (IO a)
inqVar TChan (Either SomeException a)
outqVar =
forall (f :: * -> *) a b. Applicative f => f a -> f b
forever forall a b. (a -> b) -> a -> b
$ do
IO a
job <- forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TChan a -> STM a
readTChan TChan (IO a)
inqVar
Either SomeException a
res <- forall e a. Exception e => IO a -> IO (Either e a)
try IO a
job
forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TChan a -> a -> STM ()
writeTChan TChan (Either SomeException a)
outqVar Either SomeException a
res
spawn :: TChan (IO a) -> TVar Int -> IO a -> IO ()
spawn :: forall a. TChan (IO a) -> TVar Int -> IO a -> IO ()
spawn TChan (IO a)
inqVar TVar Int
countVar IO a
job =
forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ do
forall a. TVar a -> (a -> a) -> STM ()
modifyTVar' TVar Int
countVar (forall a. Num a => a -> a -> a
+Int
1)
forall a. TChan a -> a -> STM ()
writeTChan TChan (IO a)
inqVar IO a
job
collect :: TChan (Either SomeException a) -> TVar Int -> IO a
collect :: forall a. TChan (Either SomeException a) -> TVar Int -> IO a
collect TChan (Either SomeException a)
outqVar TVar Int
countVar = do
Either SomeException a
res <- forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ do
forall a. TVar a -> (a -> a) -> STM ()
modifyTVar' TVar Int
countVar (forall a. Num a => a -> a -> a
subtract Int
1)
forall a. TChan a -> STM a
readTChan TChan (Either SomeException a)
outqVar
forall a c b. (a -> c) -> (b -> c) -> Either a b -> c
either forall e a. Exception e => e -> IO a
throwIO forall (m :: * -> *) a. Monad m => a -> m a
return Either SomeException a
res
remaining :: TVar Int -> IO Bool
remaining :: TVar Int -> IO Bool
remaining TVar Int
countVar = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (forall a. Eq a => a -> a -> Bool
/=Int
0) forall a b. (a -> b) -> a -> b
$ forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ forall a. TVar a -> STM a
readTVar TVar Int
countVar
cancel :: TChan (IO a) -> TVar Int -> IO ()
cancel :: forall a. TChan (IO a) -> TVar Int -> IO ()
cancel TChan (IO a)
inqVar TVar Int
countVar =
forall a. STM a -> IO a
atomically forall a b. (a -> b) -> a -> b
$ do
[IO a]
xs <- forall a. TChan a -> STM [a]
readAllTChan TChan (IO a)
inqVar
forall a. TVar a -> (a -> a) -> STM ()
modifyTVar' TVar Int
countVar (forall a. Num a => a -> a -> a
subtract (forall (t :: * -> *) a. Foldable t => t a -> Int
length [IO a]
xs))
readAllTChan :: TChan a -> STM [a]
readAllTChan :: forall a. TChan a -> STM [a]
readAllTChan TChan a
qvar = [a] -> STM [a]
go []
where
go :: [a] -> STM [a]
go [a]
xs = do
Maybe a
mx <- forall a. TChan a -> STM (Maybe a)
tryReadTChan TChan a
qvar
case Maybe a
mx of
Maybe a
Nothing -> forall (m :: * -> *) a. Monad m => a -> m a
return (forall a. [a] -> [a]
reverse [a]
xs)
Just a
x -> [a] -> STM [a]
go (a
xforall a. a -> [a] -> [a]
:[a]
xs)
data JobLimit = JobLimit QSem
newJobLimit :: Int -> IO JobLimit
newJobLimit :: Int -> IO JobLimit
newJobLimit Int
n =
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap QSem -> JobLimit
JobLimit (Int -> IO QSem
newQSem Int
n)
withJobLimit :: JobLimit -> IO a -> IO a
withJobLimit :: forall a. JobLimit -> IO a -> IO a
withJobLimit (JobLimit QSem
sem) =
forall a b c. IO a -> IO b -> IO c -> IO c
bracket_ (QSem -> IO ()
waitQSem QSem
sem) (QSem -> IO ()
signalQSem QSem
sem)
newtype Lock = Lock (MVar ())
newLock :: IO Lock
newLock :: IO Lock
newLock = forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap MVar () -> Lock
Lock forall a b. (a -> b) -> a -> b
$ forall a. a -> IO (MVar a)
newMVar ()
criticalSection :: Lock -> IO a -> IO a
criticalSection :: forall a. Lock -> IO a -> IO a
criticalSection (Lock MVar ()
lck) IO a
act = forall a b c. IO a -> IO b -> IO c -> IO c
bracket_ (forall a. MVar a -> IO a
takeMVar MVar ()
lck) (forall a. MVar a -> a -> IO ()
putMVar MVar ()
lck ()) IO a
act