shared-mutable-index-rmw-race-use-marker-blob-per-item SKILL.md skillA
shared-mutable-index-rmw-race-use-marker-blob-per-item from wan-huiyan/agent-traffic-control is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add wan-huiyan/agent-traffic-control/shared-mutable-index-rmw-race-use-marker-blob-per-item@v1.1.0Pins v1.1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- wan-huiyan/agent-traffic-control
- Path
plugins/agent-traffic-control/skills/shared-mutable-index-rmw-race-use-marker-blob-per-item/SKILL.md- Versions recorded
- 3
- Latest version
- v1.1.0, committed Aug 10, 2026
- First version recorded
- Jul 8, 2026
- Size
- 9,319 bytes
- Repository stars
- 3
- License
- MIT
Designing a shared "who is active / recent items" index that concurrent producers write to: one mutable list silently loses entries. Write one marker per item.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Shared mutable index → use a marker blob/row per item (not a read-modify-written list) ## Problem You are building a feature where **multiple producers concurrently register items into a shared collection, and a reader periodically prunes dead entries** — e.g. a "see everyone's in-flight runs / active sessions / recent uploads" list shown on a home/dashboard page, shared across a team / workspace / user. The tempting design is **one shared mutable container** that you read-modify-write: ```python # register (producer) # render + prune (reader) ids = read(index) ids = read(index) ids = [new_id] + dedupe(ids) live = [i for i in ids if still_alive(i)] write(index, ids[:CAP]) write(index, live) # prune ``` This has a **read-modify-write race**. Interleave two callers: 1. Reader reads `[A]`. 2. Producer reads `[A]`, computes `[X, A]`, writes `[X, A]`. 3. Reader writes its pruned copy `[A]` (computed in step 1, before X existed). **X is now permanently gone from the index.** It is never re-added — registration fires *once*, …
Read the whole file at its exact version.
How to install
mdr add wan-huiyan/agent-traffic-control/shared-mutable-index-rmw-race-use-marker-blob-per-item@sha256:2d81f643dca77cb0The line at the top of this page pins the label v1.1.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_zlyflrwrqpwsu62q)
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Versions
The registry has recorded 3 versions of this file, between Jul 8, 2026 and Aug 10, 2026, about one every 17 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v1.1.0 latest | 2026-08-10 | 5b6d8a2 | 9,319 B | A | view · diff |
| v1.1.0 | 2026-08-10 | a58c34c | 9,296 B | A | view · diff |
| v1.1.0 | 2026-07-08 | 7f737d2 | 10,469 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (9319 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
wan-huiyan/agent-traffic-control · 3 stars · license MIT · pushed 2026-09-22 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_zlyflrwrqpwsu62q GET https://markdownregistry.com/api/v1/resolve?ref=wan-huiyan/agent-traffic-control/shared-mutable-index-rmw-race-use-marker-blob-per-item GET https://markdownregistry.com/api/v1/blob/2d81f643dca77cb0004461217d217bc41850bbe170492e0b3a351355813417b0
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.