Signal inconsistency between GHC and GHCi

[Sven Panne]

Am Sonntag, 1. Januar 2006 19:40 schrieb Bulat Ziganshin:
> Sunday, January 01, 2006, 2:27:01 PM, you wrote:
> >> >> [ usleep/nanosleep trouble deleted... ]
> >>
> >> may be you comile with -threaded? ghci don't use this option, afaik
>
> SP> The SIGALRM happen with purely interpreted code and even without
> loading any SP> code at all into GHCi... :-(
>
> i say that your COMPILED code works ok because it uses -threaded, but
> GHCi fails because it just never use this option

Well, you can safely assume that I would have mentioned any strange 
commandline flags used for compilation, so don't jump to wild assumptions... 
It was plain old "ghc --make Blah.hs" on x86 SuSE Linux. And no, GHCi did not 
get any options, either.

Anyway, the question was (slightly reformulated): Why does GHCi seize the 
SIGALRM resource and why does it receive high-frequency signals even when 
idling on the prompt? Neither is this very power-saving-friendly nor 
necessary and can lead to problems with external libraries. Perhaps our RTS 
Grand Master SimonM can comment on this. :-)

Cheers,
   S.