services/api/lib/update_priorities.rb

   1 # Copyright (C) The Arvados Authors. All rights reserved.
   2 #
   3 # SPDX-License-Identifier: AGPL-3.0
   4
   5 def row_lock_for_priority_update container_uuid
   6   # Locks all the containers under this container, and also any
   7   # immediate parent containers.  This ensures we have locked
   8   # everything that gets touched by either a priority update or state
   9   # update.
  10   ActiveRecord::Base.connection.exec_query %{
  11         select 1 from containers where containers.uuid in (
  12   select pri_container_uuid from container_tree($1)
  13 UNION
  14   select container_requests.requesting_container_uuid from container_requests
  15     where container_requests.container_uuid = $1
  16           and container_requests.state = 'Committed'
  17           and container_requests.requesting_container_uuid is not NULL
  18 )
  19         order by containers.uuid for update
  20   }, 'select_for_update_priorities', [container_uuid]
  21 end
  22
  23 def update_priorities starting_container_uuid
  24   # Ensure the row locks were taken in order
  25   row_lock_for_priority_update starting_container_uuid
  26
  27   ActiveRecord::Base.connection.exec_query %{
  28 update containers set priority=computed.upd_priority from container_tree_priorities($1) as computed
  29  where containers.uuid = computed.pri_container_uuid and priority != computed.upd_priority
  30 }, 'update_priorities', [starting_container_uuid]
  31 end