windbg-user-mutex-held-across-co-await SKILL.md skillA
windbg-user-mutex-held-across-co-await from microsoft/win-dev-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add microsoft/win-dev-skills/windbg-user-mutex-held-across-co-await@git:20261007.790b577Pins git:20261007.790b577 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- microsoft/win-dev-skills
- Path
plugins/windbg/skills/windbg-user-mutex-held-across-co-await/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261007.790b577, committed Oct 7, 2026
- First version recorded
- Oct 7, 2026
- Size
- 4,245 bytes
- Repository stars
- 475
- License
- MIT
Use when app, service, or user-mode driver C++ coroutine code holds a thread-affine lock across suspension and later hangs or fails. Not for all coroutine crashes or choosing lock performance.
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
# Mutex Held Across co_await **Load `windbg-diagnostic-method` first** if it is not already loaded in this conversation, and apply it throughout for evidence ranking, hypothesis testing, confidence calibration, independent review, and report validation. This skill adds the bug-family-specific commands and evidence requirements. ## Detection This pattern can occur in native application, service, or user-mode driver code, including UMDF components that use C++ coroutines. Look for a lock acquired before `co_await` and released after resumption or coroutine destruction. Mutex ownership belongs to the acquiring thread, not the coroutine frame. A resumption on another thread can violate that contract. Even same-thread resumption can create reentrancy or progress problems when the awaited operation needs a lock the coroutine still holds. ## Workflow 1. Identify the exact lock primitive and acquisition/release scope in source. Audit every suspension point while the RAII guard or ownership is alive. 2. Establish the acquire and resume threads using trace/source evidence. Standard mutexes and SRW locks do not provide a universally queryable owner …
Read the whole file at its exact version.
How to install
mdr add microsoft/win-dev-skills/windbg-user-mutex-held-across-co-await@sha256:407528726c53c79aThe line at the top of this page pins the label git:20261007.790b577, 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_z3qhmlqjvsiuk7ek)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, all committed on Oct 7, 2026.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261007.790b577 latest | 2026-10-07 | 790b577 | 4,245 B | A | view · diff |
| git:20261007.e1050cd | 2026-10-07 | e1050cd | 4,116 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 (4245 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
microsoft/win-dev-skills · 475 stars · license MIT · pushed 2026-10-19 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_z3qhmlqjvsiuk7ek GET https://markdownregistry.com/api/v1/resolve?ref=microsoft/win-dev-skills/windbg-user-mutex-held-across-co-await GET https://markdownregistry.com/api/v1/blob/407528726c53c79ad3a314a5b297f2fb869eae963974059657842a41087485ad
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.