Module: WithPgLock

Included in:
ApplicationRecord
Defined in:
app/models/concerns/with_pg_lock.rb

Instance Method Summary collapse

Instance Method Details

#with_pg_lock(callback, criterion = proc { true }) ⇒ Object

Lock PG table, reload model and execute callback if criterion is met



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# File 'app/models/concerns/with_pg_lock.rb', line 6

def with_pg_lock(callback, criterion = proc { true })
  # Some notes:
  #
  # * nowait is a postgre specific option and may not work with other databases
  # * nowait will raise an exception if the lock can not be acquired
  # * we are using a double check lock pattern to reduce lock acquisition
  with_lock('for update nowait') do
    reload
    callback.call if criterion.call
  end if criterion.call
rescue
  nil
end