Support specifying barrier algorithms in PyConf
'Barriers' are algorithms with optional data dependencies. When declared as such, the scheduler (HLTControlFlowMgr
) will not trigger the execution of data
dependency producers if the barrier's dependencies do not already exist.
See Moore#145 (closed) for more context.
Required for Phys!884 (merged) and Moore!759 (merged).
Edited by Alex Pearce