Python get TID that matches os /proc/[pid]/

Question

I am trying to get the thread IDs (tid) that I can use to access /proc/[tid]/sched. I can look it up in the PID column of htop but when I try to access it from inside python I keep getting -1.

#!/usr/bin/env python3
import ctypes
import threading 

def get_tid():
    libc = ctypes.cdll.LoadLibrary('libc.so.6')
    print(libc.syscall(224))

threading.Thread(target=get_tid).run()

Answer 1

It's syscall 186 for me on Ubuntu 18.04

import ctypes

def get_tid():
    """System call gettid on Linux, returning thread-id."""
    return ctypes.CDLL('libc.so.6').syscall(186)

---

Python 3.8 introduced threading.get_native_id()

Return the native integral Thread ID of the current thread assigned by the kernel. This is a non-negative integer. Its value may be used to uniquely identify this particular thread system-wide (until the thread terminates, after which the value may be recycled by the OS).

Availability: Windows, FreeBSD, Linux, macOS, OpenBSD, NetBSD, AIX.