PuduLangResilience.Limiter.Engine

type: module path: "@root/src/PuduLangResilience/Limiter/Engine.pudu" fidelity: Active grammar: "[[grammar/pudu]]" depth_score: 0.75 depth_status: DEEP tags: [module] aliases: [PuduLangResilience.Limiter.Engine]

Purpose

Turns a permit algorithm into a thread-safe limiter with a wait queue.

Interface

Signatures

export type Queueing = { permitLimit: Int, queueLimit: Int, order: Limiter.QueueOrder }

export fn limiter[S](held: S, algorithm: Permits.Algorithm[S], queueing: &Queueing, clock: Clock.Clock) -> Limiter.Limiter

Linkage

• Requires: [[src/PuduLangResilience/Clock]], [[src/PuduLangResilience/Domain/Permits]], [[src/PuduLangResilience/Limiter]], [[src/PuduLangResilience/Utils/Shared]], Std.Concurrent.Cancel.
• Consumed by: [[src/PuduLangResilience/Limiter/Concurrency]], [[src/PuduLangResilience/Limiter/FixedWindow]], [[src/PuduLangResilience/Limiter/SlidingWindow]], [[src/PuduLangResilience/Limiter/TokenBucket]].

Algorithm

1. Every request and turn is decided by [[src/PuduLangResilience/Domain/Permits]] under the book's lock.
2. A queued request asks again every millisecond on the limiter's clock; a fired token withdraws it and answers Abandoned.
3. A granted lease hands its permits back to the book on release.

Negative Logic (Prohibited Paths)

• A waiter that was evicted or withdrawn never takes permits.

Edge Cases

• A request with a fired token is abandoned before it queues.

Depth

DEPTH 0.75 (DEEP). Tested by the suite mirroring this module under test/.

Grill Log

• Q: Why polling rather than wake-ups? A: Permits return by time as well as by release; one polling loop serves both, and a manual clock drives it in tests. _Rejected:_ condition signals per release (misses time-based refills).

Referenced by

[[seams/Limiter]] · [[src/PuduLangResilience/Clock]] · [[src/PuduLangResilience/Domain/Permits]] · [[src/PuduLangResilience/Limiter]] · [[src/PuduLangResilience/Limiter/Concurrency]] · [[src/PuduLangResilience/Limiter/FixedWindow]] · [[src/PuduLangResilience/Limiter/SlidingWindow]] · [[src/PuduLangResilience/Limiter/TokenBucket]] · [[src/PuduLangResilience/Limiter/_MOC]] · [[src/PuduLangResilience/Utils/Shared]] · [[subsystems/Limiting]]