Synnefo » snf-ganeti » ganeti-local

      - Use an empty dict if you don't need any lock

      - If you don't need any lock at a particular level omit that level

      - Don't put anything for the BGL level

    If you need to share locks (rather than acquire them exclusively) at one

    level you can modify self.share_locks, setting a true value (usually 1) for

    Examples:

    # Acquire all nodes and one instance

    self.needed_locks = {

      locking.LEVEL_INSTANCES: ['instance1.example.tld'],

    }

    # Acquire just two nodes

    # Lock all nodes, in shared mode

    self.needed_locks = {}

    self.share_locks[locking.LEVEL_NODE] = 1

  def CheckPrereq(self):

    """Check prerequisites.

    # that we need atomic ways to get info for a group of nodes from the

    # config, though.

    if not self.op.names:

    else:

      self.needed_locks[locking.LEVEL_NODE] = \

        _GetWantedNodes(self, self.op.names)

    self.needed_locks = {}

    self.share_locks[locking.LEVEL_NODE] = 1

    if not self.op.nodes:

    else:

      self.needed_locks[locking.LEVEL_NODE] = \

        _GetWantedNodes(self, self.op.nodes)

    # dynamic fields. For that we need atomic ways to get info for a group of

    # instances from the config, though.

    if not self.op.names:

    else:

      self.needed_locks[locking.LEVEL_INSTANCE] = \

        _GetWantedInstances(self, self.op.names)

    self.needed_locks = {}

    self.share_locks[locking.LEVEL_NODE] = 1

    if not self.op.nodes:

    else:

      self.needed_locks[locking.LEVEL_NODE] = \

        _GetWantedNodes(self, self.op.nodes)

      self.__lock.release()

class LockSet:

  """Implements a set of locks.