[pulseaudio-discuss] Making locking nicer for NFS

[David Henningsson]

On 04/03/2012 06:27 AM, Arun Raghavan wrote:
> On Thu, 2011-08-25 at 10:37 -0700, Thomas Bushnell, BSG wrote:
>> This method also has the advantage of not relying on lock promotion
>> semantics, which (apparently) will make the Windoze version easier.
>>
>>
>> Thomas
>>
>> On Thu, Aug 25, 2011 at 10:30 AM, David Henningsson
>> <david.henningsson at canonical.com>  wrote:
>>          On 08/21/2011 04:38 PM, Thomas Bushnell, BSG wrote:
>>                  Whoops. They need to repeat the read after obtaining
>>                  the write lock and
>>                  only update the file if the contents are still bad in
>>                  that case.
>>
>>
>>          Would a good handling of this be:
>>
>>          1) Open the cookie read-only
>>          2) read the cookie
>>          3) close file
>>          4) if we have a correct cookie, do nothing more
>>          5) if we have the wrong cookie, do the old handling unchanged:
>>          open with write lock, check the contents (again), and write if
>>          something is (still) wrong.
>
> Thomas, David: Any news on this? Looks like we're agreed on an approach
> and this "just" needs to be implemented now. :)

As I understand it, Thomas problem was solved somehow (see 
https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/817269/comments/8 
), and thus nobody did anything.

In the long term, maybe the cookie should move to XDG_RUNTIME_DIR [1], 
which I understand would normally reside on a tmpfs, where this is not 
an issue in the first place.

-- 
David Henningsson, Canonical Ltd.
http://launchpad.net/~diwic

[1] Yeah, I know, Ubuntu does not support that, but it seems to be 
planned for 12.10 - https://bugs.launchpad.net/bugs/894391