syncblk

syncblk is a command for coding agents from frankbolero/dotnet-dump-mcp. It costs 0 tokens per session (163 once invoked), scanned A, original, MIT.

A diagnostic command that displays synchronization blocks in a running .NET process. These blocks represent certain locks and uses of System.Threading.Monitor, which coordinates access between threads.

In plain words
What is it for?
Use it to list synchronization blocks, see their associated objects and owning threads, and inspect locking problems in a .NET process.
Why use it?
It helps investigate deadlocks, where threads wait for one another indefinitely, and lock contention, where threads are delayed waiting for shared resources.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/frankbolero/dotnet-dump-mcp/syncblk
Clone the repo
git clone --depth 1 https://github.com/frankbolero/dotnet-dump-mcp

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for syncblk

README.md
[![agentmods](https://agentmods.dev/badge/commands/frankbolero/dotnet-dump-mcp/syncblk.svg)](https://agentmods.dev/commands/frankbolero/dotnet-dump-mcp/syncblk)
Your own site
<a href="https://agentmods.dev/commands/frankbolero/dotnet-dump-mcp/syncblk"><img src="https://agentmods.dev/badge/commands/frankbolero/dotnet-dump-mcp/syncblk.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 163 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00163
Opus 5 $0.00000 $0.00081
Sonnet 5 $0.00000 $0.00033
Haiku 4.5 $0.00000 $0.00016

Measured 5d ago against content hash 7277ab4baddc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

syncblk scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

docs/commands/syncblk.md · 29 lines

What it actually says

syncblk

Displays information about synchronization blocks (thin locks and System.Threading.Monitor instances). Useful for diagnosing deadlocks and contention issues.

Usage

syncblk [-all]

Example

> syncblk -all

ClrMD Implementation

Iterate over ClrHeap.SyncBlocks.

using Microsoft.Diagnostics.Runtime;

// ... (Setup DataTarget and ClrRuntime)

foreach (var syncBlock in runtime.Heap.SyncBlocks)
{
    Console.WriteLine($"Object: {syncBlock.Object:X}, Thread: {syncBlock.OwningThread?.OSThreadId:X}");
}

Link: ClrHeap.cs

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 29 lines · 0 tokens per session scan A 7277ab4baddc

Subscribe to this mod's changes

syncblk is a command published in the GitHub repository frankbolero/dotnet-dump-mcp (12 stars, last pushed 11d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 163 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.