diff options
| author | krasimir <krasimir@chalmers.se> | 2009-12-13 18:50:29 +0000 |
|---|---|---|
| committer | krasimir <krasimir@chalmers.se> | 2009-12-13 18:50:29 +0000 |
| commit | f85232947e74ee7ef8c7b0ad2338212e7e68f1be (patch) | |
| tree | 667b886a5e3a4b026a63d4e3597f32497d824761 /src/compiler/GF/System/UseSignal.hs | |
| parent | d88a865faff59c98fc91556ff8700b10ee5f2df8 (diff) | |
reorganize the directories under src, and rescue the JavaScript interpreter from deprecated
Diffstat (limited to 'src/compiler/GF/System/UseSignal.hs')
| -rw-r--r-- | src/compiler/GF/System/UseSignal.hs | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src/compiler/GF/System/UseSignal.hs b/src/compiler/GF/System/UseSignal.hs new file mode 100644 index 000000000..20c70a568 --- /dev/null +++ b/src/compiler/GF/System/UseSignal.hs @@ -0,0 +1,72 @@ +{-# OPTIONS -cpp #-} +---------------------------------------------------------------------- +-- | +-- Module : GF.System.UseSignal +-- Maintainer : Bjorn Bringert +-- Stability : (stability) +-- Portability : (portability) +-- +-- > CVS $Date: 2005/11/11 11:12:50 $ +-- > CVS $Author: bringert $ +-- > CVS $Revision: 1.1 $ +-- +-- Allows SIGINT (Ctrl-C) to interrupt computations. +----------------------------------------------------------------------------- + +module GF.System.UseSignal where + +import Control.Concurrent (myThreadId, killThread) +import Control.Exception (SomeException,catch) +import Prelude hiding (catch) +import System.IO + +#ifdef mingw32_HOST_OS +import GHC.ConsoleHandler + +myInstallHandler handler = installHandler handler +myCatch = Catch . const +myIgnore = Ignore +#else +import System.Posix.Signals + +myInstallHandler handler = installHandler sigINT handler Nothing +myCatch = Catch +myIgnore = Ignore +#endif + +{-# NOINLINE runInterruptibly #-} + +-- | Run an IO action, and allow it to be interrupted +-- by a SIGINT to the current process. Returns +-- an exception if the process did not complete +-- normally. +-- NOTES: +-- * This will replace any existing SIGINT +-- handler during the action. After the computation +-- has completed the existing handler will be restored. +-- * If the IO action is lazy (e.g. using readFile, +-- unsafeInterleaveIO etc.) the lazy computation will +-- not be interruptible, as it will be performed +-- after the signal handler has been removed. +runInterruptibly :: IO a -> IO (Either SomeException a) +runInterruptibly a = + do t <- myThreadId + oldH <- myInstallHandler (myCatch (killThread t)) + x <- p `catch` h + myInstallHandler oldH + return x + where p = a >>= \x -> return $! Right $! x + h e = return $ Left e + +-- | Like 'runInterruptibly', but always returns (), whether +-- the computation fails or not. +runInterruptibly_ :: IO () -> IO () +runInterruptibly_ = fmap (either (const ()) id) . runInterruptibly + +-- | Run an action with SIGINT blocked. +blockInterrupt :: IO a -> IO a +blockInterrupt a = + do oldH <- myInstallHandler myIgnore + x <- a + myInstallHandler oldH + return x |
