Odd FFI behavior

[Michael Jones]

Donn,

I was able to duplicate my problem in C using SIGVTALRM.

Can someone explain the impact of using -V0 ? What does it do to performance, etc?

Mike

Sent from my iPad

> On Aug 13, 2014, at 9:56 AM, Donn Cave <donn at avvanta.com> wrote:
> 
> [ ... re -V0 ]
>> Thanks, this solved the problem.
>> 
>> I would like to know more about what the signals are doing, and
>> what am I giving up by disabling them?
>> 
>> My hope is I can then go back to the dll expert and ask why this
>> is causing their library a problem and try to see if they can
>> solve the problem from their end, etc.
> 
> I'm disgracefully ignorant about that.  When I've been forced to
> run this way, it doesn't seem to do any very obvious immediate
> harm to the application at all, but I could be missing long term
> effects.
> 
> The problem with the library might be easy to fix, and in principle
> it's sure worth looking into - while the GHC runtime delivers signals
> on an exceptionally massive scale, there are plenty of normal UNIX
> applications that use signals, maybe timers just like this for example,
> and it's easy to set up a similar test environment using setitimer(2)
> to provide the signal bombardment.  (I believe GHC actually uses
> SIGVTALRM rather than SIGALRM, but don't think it will make any
> difference.)
> 
> But realistically, in the end sometimes we can't get a fix for it,
> so it's interesting to know how -V0 works out as a work-around.
> I hope you will keep us posted.
> 
>    Donn