ADR-016 Opt-In Disposal Timeout

Status: Accepted Date: 2025-10 Tags: disposal, timeout, reliability

Problem

Symbol.asyncDispose calls release() without timeout. If backend hangs (network latency, slow queries), disposal blocks indefinitely. Manual release() supports AbortSignal, but automatic disposal doesn't—inconsistent cancellation behavior.

Decision

Add opt-in disposeTimeoutMs configuration:

• Optional field in BackendConfig (no default)
• When configured, disposal creates internal AbortController with timeout
• Timeout errors flow through onReleaseError callback
• Backend-agnostic—applies to Redis, PostgreSQL, Firestore
• Manual release() unaffected—uses caller-provided signal

Alternatives (brief)

• Default timeout (e.g., 5s) — might cause false timeouts
• Global signal configuration — too complex, no per-lock control
• Do nothing — ignores legitimate reliability concerns

Impact

• Positive: Responsiveness guarantee, observable failures, defense-in-depth
• Negative/Risks: None—opt-in with no default

Links

• Code/Docs: common/disposable.ts, common/types.ts
• Related ADRs: ADR-015 (Async RAII)