Re: Re: Cross-backend signals and administration (Was: Re: pg_terminate_backend for same-role)

On Tue, Mar 27, 2012 at 03:17:36AM +0100, Greg Stark wrote:
> I may be forgetting something obvious here but is there even a
> function to send an interrupt signal? That would trigger the same
> behaviour that a user hitting C-c would trigger which would only be
> handled at the next CHECK_FOR_INTERRUPTS which seems like it would be
> non-controversial and iirc we don't currently have a function to do
> this for other connections the user may have if he doesn't have access
> to the original terminal and doesn't have raw shell access to run
> arbitrary commands.

Sure, C-c just sends a SIGINT. But IIRC the problem wasn't so much
cancelling running queries, SIGINT appears to work fine there, it's
that a connection blocked on waiting for client input doesn't wake up
when sent a signal. To fix that you'd need to change the signal mode
and teach the various input layers (like SSL) to handle the EINTR case.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> He who writes carelessly confesses thereby at the very outset that he does
> not attach much importance to his own thoughts.
-- Arthur Schopenhauer