Module executor 

Cycle executor for [RenderPlan] — Phase 2 of LOCKLESS.md.

The executor replaces the legacy dynamic scheduler (cycle_tasks, cycle_task_deps, finished-flag sweeps in engine/runtime.rs) with count-up dependency counters over an immutable, atomically published plan:

• deps_completed[i] is a plain (non-atomic) u64 — only the dispatcher thread mutates it. A node is ready when its counter reaches cycle * indegree[i]; exactly one completion ever crosses the threshold.
• Per cycle: cycle += 1, dispatch everything in plan.sources. No counter reset, no memcpy, no scan, no allocation.
• Per plan swap (rare, user-driven): the dispatcher pulls the published plan at cycle start (ArcSwap::load_full), bumps epoch, and re-baselines deps_completed[i] = cycle * indegree[i]. The old plan always executes to completion; the swap takes effect at the next cycle boundary. Stale completions from the previous plan are dropped via epoch.

Nodes whose dependencies can never be satisfied (plan.forced, feedback loops) are dispatched once the task timeout has elapsed since cycle start, mirroring the legacy !progressed fallback: they run with stale input data, which is the standard feedback-loop behaviour.

Structs

CycleExecutor

The single-dispatcher cycle executor. Not Sync by design: all methods run on the engine dispatcher task.

ForceOutcome

Outcome of CycleExecutor::force_timeouts and CycleExecutor::abandon_node.

NodeJob

A unit of work handed to a worker: execute node of plan.