Re: Small locking bugs in hs

From: Andres Freund <andres(at)anarazel(dot)de>
To: Simon Riggs <simon(at)2ndquadrant(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Small locking bugs in hs
Date: 2009-12-28 00:16:25
Message-ID: 200912280116.25771.andres@anarazel.de
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Sunday 27 December 2009 23:10:09 Simon Riggs wrote:
> On Sun, 2009-12-27 at 20:12 +0100, Andres Freund wrote:
> > While unlikely to cause issues two new LWLockAcquire calls use the wrong
> > locking mode.
> > Patch attached.
> It's important to explain why you think something is a bug, rather than
> make that claim on its own.
Youre right.

My idea was that another SIGINT handler (e.g. normal client query cancel) is
running while CONFLICT_MODE_FATAL is issued that might get ignored. Thus the
fatal error might get ignored.
But actually that was mostly my gut feeling - I am not really understanding
the whole query cancellation process yet.
(Its not exactly unlikely that my patch does not fix that though)

I think that if under protection of a shared lock the protected objects gets
altered, that definitely needs to be commented from my pov...
In the reverse case its not as important but still a good idea.

> However, I think I see a different issue with conflict handling, so
> looking at this again was worthwhile, thanks. Will come back with more
> over next few days.
Cool.

Andres

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Andres Freund 2009-12-28 00:22:28 Re: Small locking bugs in hs
Previous Message Guillaume Lelarge 2009-12-27 23:15:51 Re: Application name patch - v3