Skip to content
sdlc

Push readiness frontier

State: open/verified · Kind: component · Audience: system

Summary

Section titled “Summary”
  • The core query: given a graph and caller-supplied state, get_ready(graph, state, opts) returns up to limit nodes runnable now — the parallel-safe frontier.
  • Push model: the caller updates state, the engine recomputes the frontier; a pure function of (graph, state).
  • Sub-capability of C-D2GO-readiness-scheduling.

Statement

Section titled “Statement”

The push readiness frontier is the load-bearing feature. A node is in the frontier iff its status is Pending and its parents’ statuses satisfy its trigger rule (C-PPXU-status-model-and-trigger-rules) — dependency satisfaction is just the default trigger rule. get_ready is the pure kernel: it computes that set, applies only the call-time where_fn and order from ReadyOptions, and returns the top limit. Schedule::ready layers registered filters (C-GUGX-eligibility-filters) and sorters (C-V44L-priority-ordering-sorters) on top. Neither executes anything or holds state of its own: the caller owns state and re-queries after each change.

This is the surface the work-runner engine calls in-process on its dispatcher tick, which is why the crate is Rust — the tick carries no child-process boundary.

What it provides

Section titled “What it provides”
  • get_ready(&Graph, &impl StatusSource, &ReadyOptions) -> Vec<ReadyNode>.
  • Query-time options on ReadyOptions: where_fn (per-node predicate), order (a sorter), limit (the parallel cap), toward (goal rank).
  • Capacity via “ask for N” — no separate capacity primitive.
use graph_scheduler::{Done, ReadyOptions, get_ready};


let opts = ReadyOptions::new().limit(4);
get_ready(&g, &Done::new(["T-1"]), &opts);
// up to 4 nodes unlocked by T-1 whose trigger rules are satisfied

ReadyOptions is #[non_exhaustive]; build it with ReadyOptions::new() and its builder methods.

Inputs

Section titled “Inputs”

Outputs

Section titled “Outputs”
  • An ordered list of up to N runnable nodes (id + attributes).

Hook points

Section titled “Hook points”

Underlying implementation

Section titled “Underlying implementation”
  • Built and tested, at packages/rust/graph-scheduler/src/ready.rs (packages/rust/graph-scheduler/tests/ready.rs).

Notes

Section titled “Notes”
  • Pure: get_ready is a function of graph and state — no hidden state, safe under concurrency. Computing the frontier is O(V + E); the cap is a bounded top-N selection.
  • An unknown dependency target reads Pending and so never satisfies the default rule, keeping its dependent out of the frontier. That is deliberate fail-safe behaviour, matching what sdlc task next does with an unresolved depends_on.

Locations

Section titled “Locations”
  • packages/rust/graph-scheduler/src/ready.rs

← Back to Capabilities