Re: help with pthread_t deprecation / api changes

[Thomas Monjalon <thomas@monjalon.net>]

10/12/2022 00:49, Tyler Retzlaff:
> On Fri, Dec 09, 2022 at 10:13:44PM +0100, Thomas Monjalon wrote:
> > 09/12/2022 21:06, Tyler Retzlaff:
> > > On Fri, Dec 09, 2022 at 08:48:14AM -0800, Stephen Hemminger wrote:
> > > > On Fri, 09 Dec 2022 08:53:57 +0100
> > > > Thomas Monjalon <thomas@monjalon.net> wrote:
> > > > 
> > > > > > > If some execution environment doesn't support thread names, it could return a string that makes it possible for a human to identify the thread, e.g. the tread id. Again, this is assuming that it is only used for debugging, trace, and similar.  
> > > > > > 
> > > > > > i think this raises a good question. is the purpose of setting a thread name
> > > > > > meant to be something we can use from the application or is it something that
> > > > > > is for debugging diagnostics and may be a best effort?  
> > > > > 
> > > 
> > > > Thomas Monjalon <thomas@monjalon.net> wrote:
> > > 
> > > > I think yes it is only for debugging.
> > > > So best effort looks to be a good approach.
> > > > I'm not sure you need to replace the functions.
> > > > Can you just complete the implementations?
> > > 
> > > the patch series put forward allows a set / get name per-lcore, where
> > > you get implicit (but not exposed via the eal api) call to underlying
> > > platform thread setname.
> > 
> > I don't understand how lcore ID and thread ID are connected.
> > You can run multiple control threads on a single lcore.
> > 
> 
> correct.
> 
> the new public api allows the set of a name on an lcore only. as a
> side-effect if the platform supports it the name is also set on the
> thread_id associated with the lcore (from lcore_config[].thread_id).
> 
> for control threads you just get the side-effect if the platform
> supports it, otherwise it is a noop.

What does it mean? which side effect? what must be supported?

> if we want set / get name at all this seemed the most usable balance
> between application consumption with debug use where available. if this
> isn't acceptable then i would suggest we simply remove both
> rte_thread_{get,set}name because as a debugging facility we cannot offer
> a consistent abstracted api which means it shouldn't be in the eal at
> all.

Why it cannot be consistent?
Please be more precise.