RE: interactive: internal error, ghc-6.0.1

[Simon Marlow]

 
 I suspect that may previous bug report on interactive interpreter 
 should be replaced with the following one, which is simple to 
 analyse.
 This is on
 
   ghc-6.0.1 
   installed from RPM on  Red Hat Linux release 7.3 (Valhalla),
   i-386 unknown.
 
 Probably, you can reduce the example several times more.
 
   ghci Main +RTS -M1m -RTS
 
   .. : Main
   .. main
   ... 
   (interactive: internal error: thread_stack: 
   weird activation record found on stack: 1564
   Please report this as a bug to [EMAIL PROTECTED] ..
 
 Probably, the interpreter manages memory in a wrong way.
 Can you reproduce the effect?

That's a bug, thanks for the report.

Just out of interest, why are you passing the -M1m flag to ghci?  This
sets a bound of 1M on GHC's memory, and causes the compacting GC to kick
in when this bound is approached (which will be almost immediately).
The bug was in the compacting garbage collector, which explains why it
hasn't shown up until now.

Cheers,
Simon
___
Glasgow-haskell-bugs mailing list
[EMAIL PROTECTED]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs

interactive: internal error, ghc-6.0.1

[Serge D. Mechveliani]

I suspect that may previous bug report on interactive interpreter 
should be replaced with the following one, which is simple to 
analyse.
This is on

  ghc-6.0.1 
  installed from RPM on  Red Hat Linux release 7.3 (Valhalla),
  i-386 unknown.

Probably, you can reduce the example several times more.

  ghci Main +RTS -M1m -RTS

  .. : Main
  .. main
  ... 
  (interactive: internal error: thread_stack: 
  weird activation record found on stack: 1564
  Please report this as a bug to [EMAIL PROTECTED] ..

Probably, the interpreter manages memory in a wrong way.
Can you reproduce the effect?

Regards,

-
Serge Mechveliani
[EMAIL PROTECTED]




---
main = let xs = [1..9000]   -- change this number
-- and see the message from ghc
   (x's, s1) = sortE compare xs
   in
   putStr $ shows s1 \n

type CompValue= Ordering
type Comparison a = a - a - CompValue

mergeE :: Comparison a - [a] - [a] - ([a],Char)
  -- Extended merge:
  -- the transposition sign '+' | '-' is also accumulated.

mergeE cp xs ys = m xs ys $ evenL xs
  where
  m [] ys _  = (ys,'+')
  m xs [] _  = (xs,'+')
  m (x:xs) (y:ys) ev = case  cp x y  of

GT - (y:zs, mulSign s ev)  where  (zs,s) = m (x:xs) ys ev
_  - (x:zs, s) where  (zs,s) = m xs (y:ys) (invSign ev)

ortE :: Comparison a - [a] - ([a],Char)
-- Extended sort:
-- the permutation sign '+' | '-'  also accumulates.
sortE _  []  = ([] , '+')
sortE _  [x] = ([x], '+')
sortE cp xs  = let  (ys ,zs) = halve xs
(ys',s1) = sortE cp ys
(zs',s2) = sortE cp zs
(us ,s3) = mergeE cp ys' zs'
   in   (us, mulSign s3 $ mulSign s1 s2)

halve :: [a] - ([a],[a])
halvexs  = h [] xs xs  where
   h ls (x:rs) (_:_:ys) = h (x:ls) rs ys
   h ls rs _= (reverse ls, rs)

mulSign :: Char - Char - Char
mulSignx   y=  if  x==y  then '+'  else '-'

invSign :: Char - Char
invSign'+'  =  '-'
invSign'-'  =  '+'

evenL :: [a] - Char
evenL [] = '+'
evenL (_:xs) = invSign $ evenL xs
---

___
Glasgow-haskell-bugs mailing list
[EMAIL PROTECTED]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs