---
id: "papers-hio-hierarchical-async-coroutines"
type: "talk"
type_label: "Talks and presentations"
title: "HIO: Hierarchical Asynchronous Coroutines & I/O"
maintainer: "Samuel M. Smith"
authors:
  - "Samuel M. Smith"
date: "2024-09"
year: 2024
reading_level: "implementer"
reading_level_label: "Implementer"
reading_level_meaning: "developers working in or against the code"
evidence: "informative"
evidence_meaning: "an author's paper, deck, tutorial or post explaining the suite"
status: "quiet"
status_meaning: "no change in six to eighteen months; still correct"
access: "public"
access_meaning: "anyone with the link"
topics:
  - "implementations"
roles:
  - "developer"
  - "infrastructure-operator"
source_url: "https://github.com/SmithSamuelM/Papers/blob/master/presentations/Hio.web.pdf"
source_license: null
source_license_note: null
found_on: "smith-papers"
kerisse_credit: false
abstract_license: "CC BY 4.0"
abstract_license_url: "https://creativecommons.org/licenses/by/4.0/"
abstract_attribution: "KSKB, the KERISuite Knowledge Base (https://kskb.dev/)"
last_checked: "2026-10-15"
kskb_url: "https://kskb.dev/cards/papers-hio-hierarchical-async-coroutines/"
kskb_app_url: "https://kskb.dev/#item/papers-hio-hierarchical-async-coroutines"
kskb_record_url: "https://kskb.dev/data/kskb/resources/papers-hio-hierarchical-async-coroutines"
kskb_markdown_url: "https://kskb.dev/export/cards/papers-hio-hierarchical-async-coroutines.md"
---

# HIO: Hierarchical Asynchronous Coroutines & I/O

A 104-slide deck by Samuel M. Smith on HIO, a model of hierarchical asynchronous coroutines and non-blocking I/O, and on flow-based programming. It covers asynchronous processing approaches, dependency inversion, data flow routing, hierarchical state and the author's earlier control-systems work.

Labels: reading level Implementer; evidence informative (an author's paper, deck, tutorial or post explaining the suite).
Source: https://github.com/SmithSamuelM/Papers/blob/master/presentations/Hio.web.pdf (license not recorded).
The abstract is KSKB's own text under Creative Commons Attribution 4.0 (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/; credit KSKB, the KERISuite Knowledge Base (https://kskb.dev/).