Feature #19850: Get thread creation time

• Status: Rejected
• Assignee: -
• Target version: -

[ngan (Ngan Pham)]

I was debugging some threads hanging issue and thought it would be nice to know how long a thread has been around for. Would there be interest in a Thread#creation_time (or some other name) that returns the time when the thread was created?

[jeremyevans0 (Jeremy Evans)]

• Tracker changed from Bug to Feature
• Backport deleted (3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN)

[mame (Yusuke Endoh)]

• Status changed from Open to Feedback

It is unclear what you expect from Thread#creation_time. Could you please explain your use case in more detail and how it is useful for the case?

[ngan (Ngan Pham)]

In the process of debugging a stuck process on production (Sidekiq), we've been dumping all the threads' backtraces. We can see a thread that's sleeping at net/http.rb. (I've filed an issue here: https://github.com/ruby/net-http/issues/149)

But I was just thinking it would be nice to know, in general, how long a thread has been running to get a better sense if this thread has been stuck for a while or not.

[nobu (Nobuyoshi Nakada)]

• Status changed from Feedback to Open

[naruse (Yui NARUSE)]

To investigate when you want to investigate what causes a program hang...

pid2line

https://gist.github.com/nurse/0619b6af90df140508c2
It shows what threads are running or sleeping and where it is as C function name.
In your case, it will show _connect.

rbspy

When it is running in infinite loop, rbspy will help where it is.
https://rbspy.github.io/

[mame (Yusuke Endoh)]

• Status changed from Open to Rejected

We discussed this at the dev meeting, and decided not to implement it.

Considering frameworks that implement a thread pool, the time when a Thread object is created is not necessarily useful, but could be rather confusing. It would be better for users or frameworks to record their own time at the start of a process.