[Interest] Packet arrival-time resolution? QUdpSocket

[Thiago Macieira]

On Thursday, 30 November 2017 13:27:16 PST Jason H wrote:
> > In more usual units:
> > 	speed of light = 299 792 458 m/s = 299.792458 mm/ns
> > 	speed of sound at STP = ~340 m/s = ~340 mm/ms
> 
> Heh, yeah, "usual" for you. but the 1ft/ns or 1ft/msec makes it 1) easy to
> remember and 2) seem that nature prefers imperial. (totally coincidence and
> joking)

Yeah, but note how my speed of light isn't approximate. :-)

> > Unless the wall-clock suffers a time jump. That's where I thought the
> > monotonic time would have been useful. You could convert it to wall-clock
> > at your leisure.
> 
> Yes, that's an option too. I'll figure it out ;-)

My point is that I couldn't get the monotonic arrival time from most OSes, so 
I can only give you the old, regular wall-clock time. If your clock suffers a 
time jump, you have to compensate yourself.

Then again, the only application that cares about time jumps when relating to 
packet arrival time is the application that performs those time jumps in the 
first place. It's called "ntpd".

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center