SimGraph.md

Nested module and queue DOT graph

SimSystem::WriteDot(std::ostream&) and SimSystem::SaveDot(path) export the built topology as Graphviz DOT. Call them after Build().

• Every SimModule becomes a labeled subgraph cluster_*. Child modules are nested inside the parent cluster.
• Every physical SimQueue<T> becomes a cylinder-shaped node inside its owning parent cluster. No root queue is allowed.
• BindOutput() produces a module-to-queue edge; BindInput() produces a queue-to-module edge. Every queue has one of each. Rings are rendered as directed cycles.
• Names are DOT escaped. Node IDs are assigned from the built registration and child order.

The graph test builds a complete parent/child pipeline and calls both export methods.

Save a diagram and render it with Graphviz when the dot CLI is available:

dot -Tsvg topology.dot -o topology.svg
dot -Tpdf topology.dot -o topology.pdf

The GFSIM library does not require Graphviz. The topology contract test also checks fixed object counts, one-to-one queue ports, legal cycles, and the 512-entry capacity limit.