hakorune/docs/private/roadmap/phases/phase-20.8/CALL_FOR_REVIEW.md

Phase 20.8 — Call for Review (Boundaries & Contracts)

Purpose

• Fix boundaries/invariants before implementation to keep Phase‑20.8 small, explicit, and deterministic.

Agenda

1. Boundary/Scope (Rust layer)

• Final responsibilities: Boot (Lock/Capsule→BootPlan), HostBridge publish, CLI flags, PluginHost init (LockOnly order)
• No discovery fallback; propagate non‑OK status to exit code

2. C‑ABI Surface (HostBridge)

• 7 functions: open/close/last_error/list_types/type_id/method_id/call
• Versioning: abi_major/minor + struct_size; caps; optional allocator pointer
• Error policy: OK/NOT_FOUND/BAD_LOCK/INCOMPATIBLE/OOM/UNSUPPORTED/VALIDATION/PANIC

3. GC v0 (Mark & Sweep)

• Roots: stack frames, global static boxes, HostBridge handles
• Safepoints: call boundaries, loop back‑edges, pre‑I/O waits
• Triggers: live_bytes growth (>80% since last sweep) or +4MB
• Metrics: pause_ms/live_bytes/num_objects/alloc_rate; HAKO_GC_TRACE format

4. Allocator/HakMem (research only)

• Not adopted in 20.8; keep docs only. MVP metrics: determinism, latency distribution, fragmentation.

5. VM Semantics/Parity

• 16 ops + Call unified; Gate‑C Strict ban list finalized
• Eq/Ne: primitive=Compare, box=op_eq, enum=.equals (Rewrite + Verifier)

6. Published Names / SSOT

• Box.method/Arity only; alias TTL→remove (2 minor releases)
• Tail fallback OFF; CallAttrs.tail_ok marks explicit cases

7. Router/Rewrite/Intern

• Known/Rewrite default ON (Enum/Callable)
• Intern: published names only; name→id JSON dump for CI
• CallAttrs: effect/may_throw/tail_ok/inline_hint consumed by VM/LLVM only

8. Determinism / Capsule / Lock

• LockOnly: fixed order; sha256 verify (plugins + optional AOT)
• Frozen: verify required; no fallback

9. WASM/Embedded

• Built‑in plugin preset via LTO/inline; Capsule “baked‑in” artifacts when dynamic load is restricted

10. AOT/FFI

• AOT: bytes_len parity; skip when AOT_PRESENT cap is absent
• FFI‑C: allow‑list only; signatures normalized via Box/Value

11. Error/Fail‑Fast

• Three guards: Verifier (Boot), Router (E_NOT_FOUND), Runner (exit code)

12. Migration/Rollback

• --backend vm-rust as last escape hatch with deprecation schedule; path‑shim deprecation→removal plan

13. KPIs/Observability/CI

• VM ≥ 70% of LLVM (representative ops); 30‑run p95 geometric means
• Determinism: Frozen runs produce identical logs/hashes (10×)
• CI: SSOT diffs (published names set, intern table), negative cases (Strict/Gate‑C), determinism checks

Expected Outcome

• Sign‑off on boundaries/contracts. Green‑light to implement GC v0 and backend deprecation with minimal risk.