Hand off the arena with explicit reasons not to use it
A second team wants the arena for long-lived session objects even though reset semantics and spill behavior were designed for packet batches.
- Focused work estimate
- 2h 30m + prerequisites
- Priority in the scenario
- Medium
- Engineering practice
- Technical writing · API contracts · Operational handoff
Estimated field mix
- Systems programming70%
- Developer tooling30%
Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence.
Review it, then add it to your workspace.
The board opens an editable draft; nothing is saved until you confirm it. Sign-in and workspace permissions apply, and Demo boards remain ephemeral.
Project context
A fictional telemetry collector copies decoded packet fields into a small native arena. The prototype misaligns wide values and reuses memory while readers still hold views. Create a local Rust crate or C library with generated byte fixtures; no device traffic or production allocator replacement is supplied.
Setup prerequisites
- Pointers and slices
- Integer overflow
- Memory alignment
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
- SMEM-101 · Specify aligned arena offsets without relying on host luck
- SMEM-102 · Return exhaustion without handing out a partial slice
- SMEM-104 · Free large spill blocks without double-releasing arena pages
- SMEM-105 · Coalesce adjacent free spans without corrupting the index
- SMEM-106 · Bound fragmentation before adding a more complex allocator
- SMEM-108 · Expose arena pressure without logging packet contents
- SMEM-103 · Invalidate borrowed packet views when the arena resets
- SMEM-107 · Contain unsafe decoding behind a length-checked cursor
- SMEM-109 · Recover a persisted arena snapshot only when its layout matches
Acceptance criteria
- Document supported lifetimes, alignment, capacity, thread-safety, and reset rules
- List measured bounds and unresolved risks with reproduction commands
- Include rejection examples for workloads better served by standard allocation
Implementation constraints
- Do not present local benchmark results as universal performance claims.
Verification to include
- Have a reviewer reproduce one supported workload from a clean checkout.
- Apply the documented long-lived workload and confirm the guide recommends against adoption.
Deliverables
- Usage contract, decision record, and reproducible handoff
Rollout and recovery
Require a separate review before any new workload adopts the component.
Value of the work
For the engineer: Practice representation invariants, lifetimes, unsafe-boundary review and memory diagnostics.
For the team: Review a component whose allocation failures and corruption cases are explicit before reuse in latency-sensitive code.
Evidence boundaries
Outcome Evidence: Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.
Ownership Evidence: Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence.