hpath/unix/System/Posix/Resource.hsc

167 lines
5.1 KiB
Haskell

{-# LANGUAGE CApiFFI #-}
#if __GLASGOW_HASKELL__ >= 709
{-# LANGUAGE Safe #-}
#else
{-# LANGUAGE Trustworthy #-}
#endif
-----------------------------------------------------------------------------
-- |
-- Module : System.Posix.Resource
-- Copyright : (c) The University of Glasgow 2003
-- License : BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer : libraries@haskell.org
-- Stability : provisional
-- Portability : non-portable (requires POSIX)
--
-- POSIX resource support
--
-----------------------------------------------------------------------------
module System.Posix.Resource (
-- * Resource Limits
ResourceLimit(..), ResourceLimits(..), Resource(..),
getResourceLimit,
setResourceLimit,
) where
#include "HsUnix.h"
import System.Posix.Types
import Foreign
import Foreign.C
-- -----------------------------------------------------------------------------
-- Resource limits
data Resource
= ResourceCoreFileSize
| ResourceCPUTime
| ResourceDataSize
| ResourceFileSize
| ResourceOpenFiles
| ResourceStackSize
#ifdef RLIMIT_AS
| ResourceTotalMemory
#endif
deriving Eq
data ResourceLimits
= ResourceLimits { softLimit, hardLimit :: ResourceLimit }
deriving Eq
data ResourceLimit
= ResourceLimitInfinity
| ResourceLimitUnknown
| ResourceLimit Integer
deriving Eq
data {-# CTYPE "struct rlimit" #-} RLimit
foreign import capi unsafe "HsUnix.h getrlimit"
c_getrlimit :: CInt -> Ptr RLimit -> IO CInt
foreign import capi unsafe "HsUnix.h setrlimit"
c_setrlimit :: CInt -> Ptr RLimit -> IO CInt
getResourceLimit :: Resource -> IO ResourceLimits
getResourceLimit res = do
allocaBytes (#const sizeof(struct rlimit)) $ \p_rlimit -> do
throwErrnoIfMinus1_ "getResourceLimit" $
c_getrlimit (packResource res) p_rlimit
soft <- (#peek struct rlimit, rlim_cur) p_rlimit
hard <- (#peek struct rlimit, rlim_max) p_rlimit
return (ResourceLimits {
softLimit = unpackRLimit soft,
hardLimit = unpackRLimit hard
})
setResourceLimit :: Resource -> ResourceLimits -> IO ()
setResourceLimit res ResourceLimits{softLimit=soft,hardLimit=hard} = do
allocaBytes (#const sizeof(struct rlimit)) $ \p_rlimit -> do
(#poke struct rlimit, rlim_cur) p_rlimit (packRLimit soft True)
(#poke struct rlimit, rlim_max) p_rlimit (packRLimit hard False)
throwErrnoIfMinus1_ "setResourceLimit" $
c_setrlimit (packResource res) p_rlimit
return ()
packResource :: Resource -> CInt
packResource ResourceCoreFileSize = (#const RLIMIT_CORE)
packResource ResourceCPUTime = (#const RLIMIT_CPU)
packResource ResourceDataSize = (#const RLIMIT_DATA)
packResource ResourceFileSize = (#const RLIMIT_FSIZE)
packResource ResourceOpenFiles = (#const RLIMIT_NOFILE)
packResource ResourceStackSize = (#const RLIMIT_STACK)
#ifdef RLIMIT_AS
packResource ResourceTotalMemory = (#const RLIMIT_AS)
#endif
unpackRLimit :: CRLim -> ResourceLimit
unpackRLimit (#const RLIM_INFINITY) = ResourceLimitInfinity
unpackRLimit other
#if defined(RLIM_SAVED_MAX)
| ((#const RLIM_SAVED_MAX) :: CRLim) /= (#const RLIM_INFINITY) &&
other == (#const RLIM_SAVED_MAX) = ResourceLimitUnknown
#endif
#if defined(RLIM_SAVED_CUR)
| ((#const RLIM_SAVED_CUR) :: CRLim) /= (#const RLIM_INFINITY) &&
other == (#const RLIM_SAVED_CUR) = ResourceLimitUnknown
#endif
| otherwise = ResourceLimit (fromIntegral other)
packRLimit :: ResourceLimit -> Bool -> CRLim
packRLimit ResourceLimitInfinity _ = (#const RLIM_INFINITY)
#if defined(RLIM_SAVED_CUR)
packRLimit ResourceLimitUnknown True = (#const RLIM_SAVED_CUR)
#endif
#if defined(RLIM_SAVED_MAX)
packRLimit ResourceLimitUnknown False = (#const RLIM_SAVED_MAX)
#endif
#if ! defined(RLIM_SAVED_MAX) && !defined(RLIM_SAVED_CUR)
packRLimit ResourceLimitUnknown _ =
error
$ "System.Posix.Resource.packRLimit: " ++
"ResourceLimitUnknown but RLIM_SAVED_MAX/RLIM_SAVED_CUR not defined by platform"
#endif
packRLimit (ResourceLimit other) _ = fromIntegral other
-- -----------------------------------------------------------------------------
-- Test code
{-
import System.Posix
import Control.Monad
main = do
zipWithM_ (\r n -> setResourceLimit r ResourceLimits{
hardLimit = ResourceLimit n,
softLimit = ResourceLimit n })
allResources [1..]
showAll
mapM_ (\r -> setResourceLimit r ResourceLimits{
hardLimit = ResourceLimit 1,
softLimit = ResourceLimitInfinity })
allResources
-- should fail
showAll =
mapM_ (\r -> getResourceLimit r >>= (putStrLn . showRLims)) allResources
allResources =
[ResourceCoreFileSize, ResourceCPUTime, ResourceDataSize,
ResourceFileSize, ResourceOpenFiles, ResourceStackSize
#ifdef RLIMIT_AS
, ResourceTotalMemory
#endif
]
showRLims ResourceLimits{hardLimit=h,softLimit=s}
= "hard: " ++ showRLim h ++ ", soft: " ++ showRLim s
showRLim ResourceLimitInfinity = "infinity"
showRLim ResourceLimitUnknown = "unknown"
showRLim (ResourceLimit other) = show other
-}