Re: [Haskell-cafe] Re: Space Leak Help
On 2/4/07, Dominic Steinitz [EMAIL PROTECTED] wrote: pad causes a stack overflow and pad1 uses up about 6m of heap. pad = pad' 0 where pad' l [] = [0x80] ++ ps where pl = (64-(l+9)) `mod` 64 ps = replicate pl 0x00 pad' l (x:xs) = x : pad' (l+1) xs pad = pad' 0 where pad' l [] = [0x80] ++ ps where pl = (64-(l+9)) `mod` 64 ps = replicate pl 0x00 pad' l (x:xs) = x : (pad' $! l+1) xs -- otherwise (l+1) it will be deferred until replicate -- Tolik ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Another Space Leak
On 2/4/07, Dominic Steinitz [EMAIL PROTECTED] wrote: test1 :: Int - [Word8] test1 n = foldl' (zipWith xor) [0x01..0x40] (blockWord8sIn512 (pad (replicate n 0x55))) test2 :: Int - [Word8] test2 n = foldl' (zipWith xor) [0x01..0x40] (bws (pad (replicate n 0x55))) The problem really is here: foldl' demands the value of 'zipWith xor xs ys' (which is a list) but not its elemants. So we need a modified zipWith: zipWith' f xs ys = forceList (zipWith f xs ys) where forceList zs = foldr seq zs zs -- Tolik ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI and LD_PRELOAD - segfault
On 9/23/06, Stephan Walter [EMAIL PROTECTED] wrote:
I'm trying to use a shared lib written in Haskell to overload C functions
via LD_PRELOAD.
[snip]
This aborts with a segfault in scheduleWaitThread() from ./libtestffi.so
The test program doesn't use threads, so I'm wondering what I did wrong?
From
http://www.haskell.org/ghc/docs/latest/html/users_guide/sec-ffi-ghc.html#using-own-main:
The call to hs_init() initializes GHC's runtime system. Do NOT try to invoke
any Haskell functions before calling hs_init(): strange things will
undoubtedly happen.
If you are using gcc you can add something like this when linking libtestffi.so:
#include HsFFI.h
extern void __stginit_Socks(void);
static void __attribute__ ((constructor)) my_init(void) {
int argc = 1;
char *argv[] = {Haskell shared object};
char **argvp = argv;
hs_init(argc, argvp);
hs_add_root(__stginit_Socks);
}
static void __attribute__ ((destructor)) my_fini(void) {
hs_exit();
}
--
Tolik
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Re: [Haskell-cafe] Re: FFI and LD_PRELOAD - segfault
On 9/24/06, Stephan Walter [EMAIL PROTECTED] wrote: gcc -g -Wall -I/usr/lib/ghc-6.4.2/include -c -o hsinit.o hsinit.c or ghc -c hsinit.c or even ghc -Wall -optl -shared -o libtestffi.so \ hsinit.c testffi.o testffi_stub.o Could anybody familiar with ghc linking details comment on this constructor/destructor thing so that we can add a wiki about building shared objects? -- Tolik ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Why is type 'b' forced to be type 'm a' and not possibly 'm a - m a'
On 9/15/06, Vivian McPhail [EMAIL PROTECTED] wrote:
class Forkable a where
fork :: String - a - a - a
...
{-
instance (Monad m, Forkable (m a), Forkable b) = Forkable (m a - b) where
fork n a1 a2 a = do
a' - a
fork n (a1 $ return a') (a2 $ return a')
-}
Let's do manual type checking.
First, fork :: Forkable a = String - a - a - a
So for Forkable (m a - b)
fork :: String - (m a - b) - (m a - b) - m a - b
Then
fork n a1 a2 a :: b
But you define it as
fork n a1 a2 a = do {...}
So it should be of type Monad t = t a, not just any `b'.
Instead, you can define
instance (Monad m, Forkable (m b)) = Forkable (m a - m b) where
...
Note that to compile it you also need -fallow-undecidable-instances
and -fallow-overlapping-instances.
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Tolik
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Re: [Haskell] How to generate a dll?
On 9/7/06, Andreas Marth [EMAIL PROTECTED] wrote:
I meant that the dll crashed Excel wenn I stopped the debugging mode and
also if I used it in a VB-projekt it crahed that when stopped.
Hi, Andreas!
Try adding these lines to your DllMain:
if (reason == DLL_PROCESS_DETACH) {
shutdownHaskell();
return TRUE;
}
If I tried to return a String (marshalled to CString) the dll just plain
crashed when called.
How exactly is it marshalled?
--
Tolik
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Re: [Haskell] using the ffi with callbacks
On 7/20/06, Evan Martin [EMAIL PROTECTED] wrote: To elaborate, the code setting this up looks something like this: callback_fcn - ... -- get a FunPtr using wrapper from the ffi free_fcn - ... -- as above -- the callback data is just stuff that needs freeing callback_data - newStablePtr (callback_fcn, free_fcn) register_callback callback_fcn callback_data free_fcn And my plan was: within the function free_fcn wraps, free callback_fcn, free the StablePtr, and then finally free free_fcn itself. As Taral mentioned there's no need in creating different free_fcn's for each new callback. The following may be considered as a linker hack but I see no reason why it could not work: freeCallback :: StablePtr (FunPtr a) - IO () freeCallback sPtr = do fPtr - deRefStablePtr sPtr freeStablePtr sPtr freeHaskellFunPtr fPtr foreign export ccall _hs_some_really_private_symbol freeCallback :: StablePtr (FunPtr a) - IO () foreign import ccall _hs_some_really_private_symbol free_fcn :: FunPtr (StablePtr (FunPtr a) - IO ()) And then you can use it like this: ... callback_data - newStablePtr callback_fcn register_callback callback_fcn callback_data free_fcn -- Tolik ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell-cafe] Arrows and 'do' syntax
On 7/12/06, Greg Fitzgerald [EMAIL PROTECTED] wrote: I'm trying to translate this HXT code to use the Arrow 'do' syntax: readWriteDoc :: String - IOSLA (XIOState s) b Int readWriteDoc path = readDocument [(a_validate, 0)] path writeDocument [(a_output_encoding, isoLatin1)] - getErrStatus This attempt fails to compile: readWriteDoc :: String - IOSLA (XIOState s) b Int readWriteDoc = proc path - do doc - readDocument [(a_validate, 0)] - path result- writeDocument [(a_output_encoding, isoLatin1)] - - doc getErrStatus - result Hi, Greg. Looks like readWriteDoc is not an arrow but a function from strings to arrows. So 'path' is just an argument, not arrow input. Maybe this should work: readWriteDoc :: String - IOSLA (XIOState s) b Int readWriteDoc path = proc input - do doc - readDocument [(a_validate, 0)] path - input result- writeDocument [(a_output_encoding, isoLatin1)] - - doc getErrStatus - result -- Tolik ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: socket TChan problem
Why do you need to duplicate channels? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
