Re: Interruptible sleeps (was Re: CommitFest 2009-07: Yay, Kevin! Thanks, reviewers!)

On 08/09/10 23:07, Martijn van Oosterhout wrote:
> On Mon, Sep 06, 2010 at 07:24:59PM +0200, Markus Wanner wrote:
>> Do I understand correctly that the purpose of this patch is to work
>> around the brokenness of select() on very few platforms? Or is there any
>> additional feature that plain signals don't give us?
>
> If the issue is just that select() doesn't get interrupted and we don't
> care about a couple of syscalls, would it not be better to simply use
> sigaction to turn on SA_RESTART just prior to the select() and turn it
> off just after. Or are these systems so broken that select() won't be
> interrupted, even if the signal handler is explicitly configured to do
> so?

I don't know if SA_RESTART is portable. But in any case, that will do 
nothing about the race condition where the signal arrives just *before* 
the select() call.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com