[Development] Thread / Process Quality of Service APIs in Qt

[Mårten Nordheim]

> -----Original Message-----
> From: Volker Hilsheimer <volker.hilsheimer at qt.io>
> Sent: torsdag 26. september 2024 17:18
> To: Mårten Nordheim <marten.nordheim at qt.io>; development at qt-
> project.org
> Subject: Re: [Development] Thread / Process Quality of Service APIs in Qt
> 
> 
> 
> > On 24 Sep 2024, at 23:23, Mårten Nordheim via Development
> <development at qt-project.org> wrote:
> >
> > Hello,
> >
> > For a while now there has been "Quality of Service" APIs available for
> threads and processes in at least Apple and Windows.
> > Typically you can request either "Eco", and Default (i.e. the OS does its
> normal thing)
> >
> > [...]
> >
> > Thanks,
> > Mårten
> 
> 
> Based on my interpretation, I think we can start with a low-level but dirt-
> simple API that allows applications set a preferred CPU core type (e.g. Eco vs
> Default) on which a thread might run, together with the existing thread
> priority.
> 
> Coupling thread priority and preferred CPU type into a “task type” or “load
> category” as a convenient, higher-level abstraction can be a follow-up,
> utilising the former lower-level API. Good naming of those seems hard; I’d
> stay away from domain specific task type names like “AudioProcessing”.
> 
> Not sure if it’s useful to have a QCoreApplication API in addition to a QThread
> API; I’d expect that calling the static QThread setters from main() would be the
> same as calling the QCoreApplication setter.
> 
> Volker

On Windows there is an API for setting it on the process-level. And I thought
there was one for macOS as well, but it seems to be more focused on labelling
the workloads that the application is doing, rather than labelling the whole
application. So, thread-specific is a safe choice.

Mårten