open-wc/coordination/claims/M03-RND-SCHEDULER-001.md

M03-RND-SCHEDULER-001 — Bounded render budget scheduler

Ownership

• Target: M03
• Program: RND
• Owner/Agent ID: sindo-main-codex
• Branch: work/sindo-main-codex/m03-render-budget-scheduler
• Lease expires UTC: 2026-07-18
• Integrator: M03 milestone integrator

Outcome

Extract the streamer's per-frame main-thread operation quotas into a scene-free RenderBudgetScheduler, preserving existing queue priority and quota values and stopping permit issuance after renderer teardown cancellation.

Non-goals

• Move queue, worker-task, cache, Node, Resource or RID ownership out of the streamer.
• Change queue ordering, concurrency limits, exported defaults or visual behavior.
• Add a generic job framework, priority graph, time-based adaptive budgeting or dependency.
• Change cache formats, renderer profiles or target milestone status.

Paths

• Exclusive: src/render/streaming/render_budget_scheduler.gd, src/tools/verify_render_budget_scheduler.gd, docs/modules/render-budget-scheduler.md, this claim
• Shared/hotspots: src/scenes/streaming/streaming_world_loader.gd, docs/modules/world-renderer.md, docs/modules/README.md, RENDER.md, targets/03-renderer-facade.md
• Generated/ignored: .godot, native DLL, generated cache resources and proprietary renderer corpus

Contracts and data

• Input: immutable per-frame map from documented operation lane IDs to non-negative operation limits
• Output: boolean permits and remaining/consumed diagnostic snapshots
• Lifecycle: begin_frame resets permits; cancel permanently rejects permits for the current scheduler instance
• Queue contents, ordering, task concurrency and schema/cache versions: unchanged
• Consumer: StreamingWorldLoader main-thread queue/finalize drains

Dependencies

• Requires: integrated M03 facade and streaming planner on master 650d584
• Blocks: renderer performance regression gate and per-service extraction
• External state: none; tests use synthetic lane limits and no world assets

Verification

• Commands: dedicated scheduler verifier, facade/planner/focus/coordinate regressions, renderer manifest/dry-run and repository gates
• Fixtures: shared lane priority, independent lanes, zero/negative limits, frame reset, unknown lane and cancellation
• Fidelity evidence: operation defaults and loop order are captured before migration; all seven renderer checkpoint plans remain valid
• Performance budget: permit checks are constant-time dictionary operations and create no Node, Resource, worker task, cache entry or RID

Documentation deliverables

• Inline API docs for scheduler lifecycle, permits and diagnostics
• New module specification with input/output table, data-flow, sequence and lifecycle diagrams
• Updated world-renderer flow/ownership/source map, module registry and renderer notes

Simplicity and naming

• Important name: RenderBudgetScheduler
• Simplest approach: one small main-thread service with named quota lanes
• Rejected complexity: generic job graph, callbacks, queue ownership, adaptive timing controller, service container or third-party dependency
• Unavoidable complexity: chunk removal and creation intentionally share one lane so removal retains priority while consuming the same historical budget
• Measured optimization evidence: no optimization claim; exact bounded extraction

Status

• State: ready-for-review
• Done: extracted all 16 historical operation quotas, migrated ordered drains, added terminal teardown cancellation, asset-free verification and module docs
• Next: M03 integrator reviews and merges e52f703
• Blocked by:

Handoff

• Commit: e52f703
• Results: RenderBudgetScheduler owns only per-frame lane counters and terminal cancellation; StreamingWorldLoader retains queue order, task/cache/node/RID ownership and operation execution. Chunk removal/create share one historical budget.
• Verification: scheduler cases=6 iterations=20000 elapsed_ms=7.495; planner cases=5 average_ms=1.879; facade/focus contracts passed; coordinate boundary files=111 consumers=6; renderer manifest checkpoints=7 coverage=7 caches=7; shutdown ownership, documentation, coordination and diff gates passed.
• Fidelity: exported defaults, quality presets, queue order, operation sites, cache versions and visible rendering rules are unchanged. Seven checkpoint plans remain valid. No build-12340 parity claim is added.
• External/local inputs: ignored native DLL and two generated ADT resource scripts were copied from master only for the worktree parse/smoke and then removed. Proprietary extracted ADT data was unavailable, producing expected degraded-data diagnostics.
• Remaining risks: queue storage length and worker concurrency remain streamer-owned; cancellation stops permit issuance but does not interrupt in-flight work; exact p95/p99 impact still requires an asset-backed baseline.
• Documentation: new scheduler module spec with API, input/output, data-flow, sequence, lifecycle, ownership, cancellation, performance and source-map sections; world renderer, module registry and renderer implementation notes updated.