def _lock_subnetpool(self):
"""Lock subnetpool associated row.
This method disallows to allocate concurrently 2 subnets in the same
subnetpool, it's required to ensure non-overlapping cidrs in the same
subnetpool.
"""
current_hash = (self._context.session.query(
models_v2.SubnetPool.hash).filter_by(
id=self._subnetpool['id']).scalar())
if current_hash is None:
# NOTE(cbrandily): subnetpool has been deleted
raise n_exc.SubnetPoolNotFound(
subnetpool_id=self._subnetpool['id'])
new_hash = uuidutils.generate_uuid()
# NOTE(cbrandily): the update disallows 2 concurrent subnet allocation
# to succeed: at most 1 transaction will succeed, others will be
# rollbacked and be caught in neutron.db.v2.base
query = self._context.session.query(models_v2.SubnetPool).filter_by(
id=self._subnetpool['id'], hash=current_hash)
count = query.update({'hash': new_hash})
if not count:
raise db_exc.RetryRequest()
def _get_subnetpool(self, context, id):
subnetpool = subnetpool_obj.SubnetPool.get_object(
context, id=id)
if not subnetpool:
raise exceptions.SubnetPoolNotFound(subnetpool_id=id)
return subnetpool
def _get_subnetpool(self, context, id):
try:
return self._get_by_id(context, models_v2.SubnetPool, id)
except exc.NoResultFound:
raise n_exc.SubnetPoolNotFound(subnetpool_id=id)
