[Kimchi-devel] [PATCHv2 1/2] Make vms model to be a singleton

[Sheldon]

Reviewed-by: ShaoHe Feng <shaohef at linux.vnet.ibm.com>

So you will add a new patch and instantiate the VMsModel right?

Sure you can use Model instance.
I'm not sure VMsModel instance or Model instance which is better.

But IMO, it seems good to Make vms model to be a singleton.
But there is not a lock for our Singleton. not sure there is a race.


On 03/05/2014 04:14 PM, lvroyce at linux.vnet.ibm.com wrote:
> From: Royce Lv <lvroyce at linux.vnet.ibm.com>
>
> In vms model __init__ function, a backgroud task is started:
>
>      self.guests_stats_thread = BackgroundTask(GUESTS_STATS_INTERVAL,
>                                                self._update_guests_stats)
>      self.guests_stats_thread.start()
>
> when VMsModel.get_list() need to be called
> ([PATCH]Add volume ref_cnt: Add model and mockmodel implementation)
> one more background task is started.
>
> This is not able to be fixed by staticmethod
> because connection will not be passed by controller.
> So make vms model a singleton.
>
> Signed-off-by: Royce Lv <lvroyce at linux.vnet.ibm.com>
> ---
>   src/kimchi/model/vms.py | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
> index 3f3a152..0d029eb 100644
> --- a/src/kimchi/model/vms.py
> +++ b/src/kimchi/model/vms.py
> @@ -27,6 +27,7 @@ from cherrypy.process.plugins import BackgroundTask
>
>   from kimchi import vnc
>   from kimchi import xmlutils
> +from kimchi.basemodel import Singleton
>   from kimchi.config import READONLY_POOL_TYPE
>   from kimchi.exception import InvalidOperation, InvalidParameter
>   from kimchi.exception import MissingParameter, NotFoundError, OperationFailed
> @@ -53,6 +54,8 @@ stats = {}
>
>
>   class VMsModel(object):
> +    __metaclass__ = Singleton
> +
>       def __init__(self, **kargs):
>           self.conn = kargs['conn']
>           self.objstore = kargs['objstore']


-- 
Thanks and best regards!

Sheldon Feng(冯少合)<shaohef at linux.vnet.ibm.com>
IBM Linux Technology Center