uthreads(8)

📦 version 0.36.1, in alpine 3.24, debian bookworm, debian trixie, nixpkgs unstable, opensuse-leap 16.0, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

🎀 NAME 🎀

uthreads, cthreads, and javathreads are the tools for the job, and they all do one thing: they trace thread creation events in Java or pthreads ✨

🦋 SYNOPSIS 🦋

cthreads [-h] [-v] pid
javathreads [-h] [-v] pid
uthreads [-h] [-l {c,java,none}] [-v] pid

💖 DESCRIPTION 💖

okay so this bad boy traces thread creation events in Java processes, or pthread creation events in any process 😭 Whenever a thread gets created, it prints out that thread's name or start address. iconic.

🔒 Since this uses BPF, only the root user can run this tool. Not you, not me, only root 💀

📋 REQUIREMENTS 📋

You'll need CONFIG_BPF and bcc. No cap, you need both or it's not happening 🫶

🌸 OPTIONS 🌸

  • -l {c,java,none} — pick the language you want to trace. c and none only trace pthreads, no matter what runtime the process is actually running 🧚
  • -v — prints out the resulting BPF program. This is for debugging, so bring it out when something's acting sus 🔍
  • pid — the process ID you want to trace 🍓

🧚 EXAMPLES 🧚

Trace Java thread creations:

# uthreads -l java 148

Trace pthread creations:

# uthreads 1802

💅 FIELDS 💅

  • TIME — the event's time in seconds, counted from when the trace started ⏱️
  • ID — the thread's ID. What shows up here depends on the runtime, so it's giving "it depends" 🌈
  • TYPE — the event type: thread start, thread stop, or pthread event 🔥
  • DESCRIPTION — the thread's name, or the function name of its start address ✨

🫧 OVERHEAD 🫧

Thread start and stop events don't happen all that often, so this tool's overhead is basically nothing. Lowkey iconic 💜

🌍 SOURCE 🌍

This one comes from bcc, bestie 🦋

https://github.com/iovisor/bcc

Also check out the bcc distribution for a companion _example.txt file. It has example usage, output, and commentary for this tool, and it's so worth a look 📚

🐧 OS 🐧

Linux only 🐧

🚧 STABILITY 🚧

Unstable, still in development. Be gentle with it 🥺

👑 AUTHOR 👑

Sasha Goldshtein, the queen who made this ✨

🔗 SEE ALSO 🔗

ustat(8), trace(8)

Okay bestie, that's the whole manual for uthreads(8) from the USER COMMANDS section, dated 2018-10-09 💖 Now go trace some threads and slay 💅🫶

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