{-# OPTIONS_GHC -optc-D_GNU_SOURCE #-}
{-# LINE 1 "src-ofd/Lukko/OFD.hsc" #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE InterruptibleFFI #-}
{-# LANGUAGE Trustworthy #-}
module Lukko.OFD (
FileLockingNotSupported(..),
fileLockingSupported,
FileLockingSupported,
FileLockingMethod (..),
fileLockingMethod,
LockMode(..),
FD,
fdOpen,
fdClose,
fdLock,
fdTryLock,
fdUnlock,
hLock,
hTryLock,
hUnlock,
) where
import Control.Monad (void)
import System.IO (Handle)
import Data.Function
import Foreign.C.Error
import Foreign.C.Types
import Foreign.Marshal.Utils
import Foreign.Storable
import GHC.IO.Exception
import GHC.Ptr
import System.Posix.Types (COff, CPid)
import Lukko.Internal.FD
import Lukko.Internal.FillBytes
import Lukko.Internal.Types
fileLockingSupported :: Bool
fileLockingSupported :: Bool
fileLockingSupported = Bool
True
type FileLockingSupported = True
fileLockingMethod :: FileLockingMethod
fileLockingMethod :: FileLockingMethod
fileLockingMethod = FileLockingMethod
MethodOFD
fdLock :: FD -> LockMode -> IO ()
fdLock :: FD -> LockMode -> IO ()
fdLock FD
fd LockMode
mode = IO Bool -> IO ()
forall (f :: * -> *) a. Functor f => f a -> f ()
void (Maybe Handle -> FD -> String -> LockMode -> Bool -> IO Bool
lockImpl Maybe Handle
forall a. Maybe a
Nothing FD
fd String
"fdLock" LockMode
mode Bool
True)
fdTryLock :: FD -> LockMode -> IO Bool
fdTryLock :: FD -> LockMode -> IO Bool
fdTryLock FD
fd LockMode
mode = Maybe Handle -> FD -> String -> LockMode -> Bool -> IO Bool
lockImpl Maybe Handle
forall a. Maybe a
Nothing FD
fd String
"fdTryLock" LockMode
mode Bool
False
fdUnlock :: FD -> IO ()
fdUnlock :: FD -> IO ()
fdUnlock = FD -> IO ()
unlockImpl
hLock :: Handle -> LockMode -> IO ()
hLock :: Handle -> LockMode -> IO ()
hLock Handle
h LockMode
mode = do
FD
fd <- Handle -> IO FD
handleToFd Handle
h
IO Bool -> IO ()
forall (f :: * -> *) a. Functor f => f a -> f ()
void (Maybe Handle -> FD -> String -> LockMode -> Bool -> IO Bool
lockImpl (Handle -> Maybe Handle
forall a. a -> Maybe a
Just Handle
h) FD
fd String
"hLock" LockMode
mode Bool
True)
hTryLock :: Handle -> LockMode -> IO Bool
hTryLock :: Handle -> LockMode -> IO Bool
hTryLock Handle
h LockMode
mode = do
FD
fd <- Handle -> IO FD
handleToFd Handle
h
Maybe Handle -> FD -> String -> LockMode -> Bool -> IO Bool
lockImpl (Handle -> Maybe Handle
forall a. a -> Maybe a
Just Handle
h) FD
fd String
"hTryLock" LockMode
mode Bool
False
hUnlock :: Handle -> IO ()
hUnlock :: Handle -> IO ()
hUnlock Handle
h = do
FD
fd <- Handle -> IO FD
handleToFd Handle
h
FD -> IO ()
unlockImpl FD
fd
foreign import ccall interruptible "fcntl"
c_fcntl :: CInt -> CInt -> Ptr FLock -> IO CInt
data FLock = FLock { FLock -> CShort
l_type :: CShort
, FLock -> CShort
l_whence :: CShort
, FLock -> COff
l_start :: COff
, FLock -> COff
l_len :: COff
, FLock -> CPid
l_pid :: CPid
}
instance Storable FLock where
sizeOf :: FLock -> Int
sizeOf FLock
_ = (Int
32)
{-# LINE 131 "src-ofd/Lukko/OFD.hsc" #-}
alignment _ = 8
{-# LINE 132 "src-ofd/Lukko/OFD.hsc" #-}
poke ptr x = do
fillBytes ptr 0 (sizeOf x)
(\hsc_ptr -> pokeByteOff hsc_ptr 0) ptr (l_type x)
{-# LINE 135 "src-ofd/Lukko/OFD.hsc" #-}
(\hsc_ptr -> pokeByteOff hsc_ptr 2) ptr (l_whence x)
{-# LINE 136 "src-ofd/Lukko/OFD.hsc" #-}
(\hsc_ptr -> pokeByteOff hsc_ptr 8) ptr (l_start x)
{-# LINE 137 "src-ofd/Lukko/OFD.hsc" #-}
(\hsc_ptr -> pokeByteOff hsc_ptr 16) ptr (l_len x)
{-# LINE 138 "src-ofd/Lukko/OFD.hsc" #-}
(\hsc_ptr -> pokeByteOff hsc_ptr 24) ptr (l_pid x)
{-# LINE 139 "src-ofd/Lukko/OFD.hsc" #-}
peek ptr = do
x1 <- (\hsc_ptr -> peekByteOff hsc_ptr 0) ptr
{-# LINE 141 "src-ofd/Lukko/OFD.hsc" #-}
x2 <- (\hsc_ptr -> peekByteOff hsc_ptr 2) ptr
{-# LINE 142 "src-ofd/Lukko/OFD.hsc" #-}
x3 <- (\hsc_ptr -> peekByteOff hsc_ptr 8) ptr
{-# LINE 143 "src-ofd/Lukko/OFD.hsc" #-}
x4 <- (\hsc_ptr -> peekByteOff hsc_ptr 16) ptr
{-# LINE 144 "src-ofd/Lukko/OFD.hsc" #-}
x5 <- (\hsc_ptr -> peekByteOff hsc_ptr 24) ptr
{-# LINE 145 "src-ofd/Lukko/OFD.hsc" #-}
return (FLock x1 x2 x3 x4 x5)
lockImpl :: Maybe Handle -> FD -> String -> LockMode -> Bool -> IO Bool
lockImpl :: Maybe Handle -> FD -> String -> LockMode -> Bool -> IO Bool
lockImpl Maybe Handle
mh (FD CInt
fd) String
ctx LockMode
mode Bool
block = do
FLock -> (Ptr FLock -> IO Bool) -> IO Bool
forall a b. Storable a => a -> (Ptr a -> IO b) -> IO b
with FLock
flock ((Ptr FLock -> IO Bool) -> IO Bool)
-> (Ptr FLock -> IO Bool) -> IO Bool
forall a b. (a -> b) -> a -> b
$ \Ptr FLock
flock_ptr -> (IO Bool -> IO Bool) -> IO Bool
forall a. (a -> a) -> a
fix ((IO Bool -> IO Bool) -> IO Bool)
-> (IO Bool -> IO Bool) -> IO Bool
forall a b. (a -> b) -> a -> b
$ \IO Bool
retry -> do
CInt
ret <- CInt -> CInt -> Ptr FLock -> IO CInt
c_fcntl CInt
fd CInt
mode' Ptr FLock
flock_ptr
case CInt
ret of
CInt
0 -> Bool -> IO Bool
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
True
CInt
_ -> IO Errno
getErrno IO Errno -> (Errno -> IO Bool) -> IO Bool
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \Errno
errno -> case () of
()
_ | Bool -> Bool
not Bool
block Bool -> Bool -> Bool
&& Errno
errno Errno -> Errno -> Bool
forall a. Eq a => a -> a -> Bool
== Errno
eWOULDBLOCK -> Bool -> IO Bool
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
False
| Errno
errno Errno -> Errno -> Bool
forall a. Eq a => a -> a -> Bool
== Errno
eINTR -> IO Bool
retry
| Bool
otherwise -> IOException -> IO Bool
forall a. IOException -> IO a
ioException (IOException -> IO Bool) -> IOException -> IO Bool
forall a b. (a -> b) -> a -> b
$ String -> Errno -> Maybe Handle -> Maybe String -> IOException
errnoToIOError String
ctx Errno
errno Maybe Handle
mh Maybe String
forall a. Maybe a
Nothing
where
flock :: FLock
flock = FLock :: CShort -> CShort -> COff -> COff -> CPid -> FLock
FLock { l_type :: CShort
l_type = case LockMode
mode of
LockMode
SharedLock -> CShort
0
{-# LINE 160 "src-ofd/Lukko/OFD.hsc" #-}
LockMode
ExclusiveLock -> CShort
1
{-# LINE 161 "src-ofd/Lukko/OFD.hsc" #-}
, l_whence :: CShort
l_whence = CShort
0
{-# LINE 162 "src-ofd/Lukko/OFD.hsc" #-}
, l_start :: COff
l_start = COff
0
, l_len :: COff
l_len = COff
0
, l_pid :: CPid
l_pid = CPid
0
}
mode' :: CInt
mode'
| Bool
block = CInt
38
{-# LINE 168 "src-ofd/Lukko/OFD.hsc" #-}
| otherwise = 37
{-# LINE 169 "src-ofd/Lukko/OFD.hsc" #-}
unlockImpl :: FD -> IO ()
unlockImpl :: FD -> IO ()
unlockImpl (FD CInt
fd) = do
let flock :: FLock
flock = FLock :: CShort -> CShort -> COff -> COff -> CPid -> FLock
FLock { l_type :: CShort
l_type = CShort
2
{-# LINE 173 "src-ofd/Lukko/OFD.hsc" #-}
, l_whence :: CShort
l_whence = CShort
0
{-# LINE 174 "src-ofd/Lukko/OFD.hsc" #-}
, l_start :: COff
l_start = COff
0
, l_len :: COff
l_len = COff
0
, l_pid :: CPid
l_pid = CPid
0
}
String -> IO CInt -> IO ()
forall a. (Eq a, Num a) => String -> IO a -> IO ()
throwErrnoIfMinus1_ String
"hUnlock"
(IO CInt -> IO ()) -> IO CInt -> IO ()
forall a b. (a -> b) -> a -> b
$ FLock -> (Ptr FLock -> IO CInt) -> IO CInt
forall a b. Storable a => a -> (Ptr a -> IO b) -> IO b
with FLock
flock ((Ptr FLock -> IO CInt) -> IO CInt)
-> (Ptr FLock -> IO CInt) -> IO CInt
forall a b. (a -> b) -> a -> b
$ CInt -> CInt -> Ptr FLock -> IO CInt
c_fcntl CInt
fd CInt
37
{-# LINE 180 "src-ofd/Lukko/OFD.hsc" #-}