Propagation engines

The update propagation strategy is implemented by a propagation engine. This library originated as a research project to compare multiple parallel propagation algorithms; however, those that did not perform well have been removed or consolidated, so three distinct engines remain:

Engine	Description
Toposort	Single-threaded propagation with minimum overhead. Also supports parallelism.
Pulsecount	Scalable parallel updating at the cost of additional overhead.
Subtree	A hybrid approach between single-threaded Toposort and Pulsecount to balance overhead and parallel utilization.

Selecting an engine

As a general guideline, if your graph consists of trivial operations only, parallelization is not worth it, so use Toposort<sequential>.

If it mostly consists of expensive operations, use Pulsecount<parallel>.

If it contains some expensive operations but mostly trivial nodes, use Subtree<parallel>.