Hi Niklas, I think that I'm doing this in my try2 function with tryAny and catchAny functions. Unfortunately that didn't work. I'm just starting with Haskell so maybe also my implementation of my haskell code is not 100% correct. cheers, m. On Mon, Sep 23, 2013 at 1:36 PM, Niklas Hambüchen wrote:

If you cannot do it with Haskell exceptions, I guess you need to look how you would do it in plain C in do the same.

Keep in mind that if something crashes in a C library, that library might have corrupted (or leaked) any memory it had access to.

I guess a somewhat reliable way is to fork an OS process, and run your crashy DLL in that; if it dies, the OS will keep care of cleaning up the low level garbage.

On Mon 23 Sep 2013 17:37:49 SGT, Miro Karpis wrote:

...

Please, can you help me with following: I have an external dll that I'm importing in my haskell program. In some particular cases the dll crashes.

Simplified: first I need to send to dll with MethodA some parameters and then call MethodB to do some calculations on those parameters. If I didn't give enough parameters then MethodB will crash the whole dll and my Haskell application.

Is there a way to handle this? Unfortunately there are no exceptions thrown from the dll.

In ghci I'm getting following message: ERROR in InitNumericalSystem::initializeSystem. JuncLabel.

I have tried to use "catchAny but that didn't help. c_run is my external dll method which takes 4 input parameters:

catchAny :: IO a -> (SomeException -> IO a) -> IO a catchAny = Control.Exception.catch

main :: IO () main = do let timeTot = []::[CDouble] timeNow = []::[CDouble] runType = 2::CInt timeTotPtr <- newArray timeTot timeNowPtr <- newArray timeNow result <- (catchAny $ c_run timeTotPtr runType timeNowPtr 0) $ \e -> do putStrLn $ "Got an exception: " ++ show e putStrLn "Returning dummy value of -1" return (-1) free timeTotPtr free timeNowPtr print result

I have tried also with withAsync, and no luck

tryAny :: IO a -> IO (Either SomeException a) tryAny action = withAsync action waitCatch

catchAny :: IO a -> (SomeException -> IO a) -> IO a catchAny action onE = tryAny action >>= either onE return

try2 :: IO () try2 = do let timeTot = []::[CDouble] timeNow = []::[CDouble] runType = 2::CInt timeTotPtr <- newArray timeTot timeNowPtr <- newArray timeNow putStrLn $ "c_run going to call c_run.." result <- catchAny (c_run timeTotPtr runType timeNowPtr 0) (const $ return (-1)) free timeTotPtr free timeNowPtr putStrLn $ "Result: " ++ show result

Is there a way how I can handle this?

cheers, m.

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Thanks for that. I checked forkProcess - which is packed in POSIX module. I'm building under windows. Do I need to go via cygwin, is there some other way for creating new OS process? m. On Mon, Sep 23, 2013 at 1:46 PM, Niklas Hambüchen wrote:

Hey,

I don't think any of your code actually forks of an *OS process*.

There three main kinds of threading constructs:

* Haskell threads (forkIO) * Operating System threads (forkOS) * Operating System processes (forkProcess, fork() in C)

Async uses the first one, you will need last one (which is similar to effectively start two Haskell programs).

On 23/09/13 20:41, Miro Karpis wrote:

...

Hi Niklas, I think that I'm doing this in my try2 function with tryAny and catchAny functions. Unfortunately that didn't work. I'm just starting with Haskell so maybe also my implementation of my haskell code is not 100% correct.