On 09/03/2015 08:42 AM, Bron Gondwana wrote:
IOERROR: failed to create fastmail.com!user.REDACTED.#calendars (Mailbox is
locked)
We get these occasionally, and I wondered why until just now, when I
remembered...
The initial CREATE or RENAME lock.. it's a mboxname_lock EXCLUSIVE, and it's taken
with nowait, and error if exists. It needs to, because the source mailbox is locked,
and you need to break a lock loop if you issued rename A => B and rename B => A
in parallel.
So it was assumed as being not a problem, because you'd never try to create the
same name twice concurrently. The name didn't exist before, so nobody will be
looking at it.
When I say "it was assumed", I mean that I assumed. In 2009 some time.
But that's not true when you're autocreating the same name when you try to read
something. Anything.
In fact, the way that the parser works, you wind up doing it for any http
request. So you get a race between two processes, one loses, logs this.
We should probably fix this :)
Bron.
Doesn't the current code check to see if the calendar-home-set mailbox
(and others) exist before trying to CREATE them?
--
Kenneth Murchison
Principal Systems Software Engineer
Carnegie Mellon University
