Package: ghc6 Version: 6.6.1-2 Severity: normal If a program is printing a lot of strings rapidly, and is run with runghc, sometimes ctrl-c won't interrupt it. If ctrl-c is then hit a second time, it says this and hangs:
<interactive>: exception :: GhcException
strace shows:
waitpid(23028, <unfinished ...>
Example program to reproduce the problem follows. (Have pity, it's my
first haskell code.) If main is changed to use faststarAt instead of
starAt, the bug is much less likely to appear. I see it about 50% of the
time using starAt, and have never seen it yet using faststarAt. (If I
compile either version, it works fine.)
x s n = take n (repeat s)
putStrs = putStr.unlines
isStarAt a b char
| a == b || a == b-1 = '*'
| otherwise = char
starAt pos s = [ isStarAt pos i (s !! (i-1)) | i <- [1..length(s)] ]
faststarAt pos s = (take (pos-1) s) ++ "**" ++ (drop (pos+1) s)
plot i = 40 + 38 * sin(i / 9)
name = unwords $ "JOEY HESS" `x` 8
main = putStrs $ [ starAt (truncate $ plot i) name | i <- [1..]]
-- System Information:
Debian Release: lenny/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.22-3-686 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages ghc6 depends on:
ii gcc 4:4.2.2-1 The GNU C compiler
ii haskell-utils 1.9 Utilities used by the Debian Haske
ii libc6 2.7-5 GNU C Library: Shared libraries
ii libgmp3-dev 2:4.2.2+dfsg-1 Multiprecision arithmetic library
ii libgmp3c2 2:4.2.2+dfsg-1 Multiprecision arithmetic library
ii libncurses5 5.6+20071215-1 Shared libraries for terminal hand
ii libreadline5 5.2-3 GNU readline and history libraries
ii libreadline5-dev 5.2-3 GNU readline and history libraries
ii perl [perl5] 5.8.8-12 Larry Wall's Practical Extraction
ghc6 recommends no packages.
-- no debconf information
--
see shy jo
signature.asc
Description: Digital signature
