linux-kernel - Why does Linux not implement pthread_suspend() and pthread

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Date: Sun, 14 Jan 2024 12:20:04 +0100
From: "Dr. Henning Kopp" <hkopp22@...oo.de>
To: linux-kernel@...r.kernel.org
Subject: Why does Linux not implement pthread_suspend() and pthread_resume()?

Hi everyone,

I have a question regarding pthreads. In particular, I was wondering why 
there is no way to suspend and resume a thread in Linux.

In Windows, there is SuspendThread() and ResumeThread() from 
processthreadsapi.h. However in Linux, there does not seem to be a 
similar function in pthread.h.

When researching this issue i found multiple ways to work around the 
inability of suspending a thread, such as using mutexes. But my question 
is why nobody bothered implementing suspending/resuming threads.

I found one answer on stackoverflow [1] that mentions that 
pthread_suspend and pthread_resume_np is in the "Unix specification", 
but not implemented in Linux. I tried to follow up on this hint and get 
access to the Posix spec, but i am not affiliated with a university 
anymore, so i was unable to download the spec.

I read "man 7 pthreads". It mentions that there are two Linux 
implementations of Posix threads, that differ in some details from the 
Posix spec. However, it does not mention suspending or resuming threads 
at all.

I hope this is the right mailing list for my question. If it is 
off-topic, please accept my apologies.

So my question is: What is the reason that Linux does not implement 
functions for suspending and resuming threads?

Best regards
Henning

[1] 
https://stackoverflow.com/questions/11468333/linux-threads-suspend-resume/13399592#13399592