Re: [PATCH v1 1/1] app/testpmd: add sleep command

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, May 02, 2025 at 04:35:08PM +0200, Burakov, Anatoly wrote:
> On 5/2/2025 2:37 PM, Bruce Richardson wrote:
> > On Fri, May 02, 2025 at 01:27:29PM +0100, Anatoly Burakov wrote:
> > > Test-pmd already has a way to run a list of commands from file, but there
> > > is no way to pause execution for a specified amount of time between two
> > > commands. This may be necessary for simple automation, particularly for
> > > waiting on some asynchronous operation such as link status update.
> > > 
> > > Add a simple sleep command to wait until certain number of milliseconds has
> > > passed.
> > > 
> > > Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> > > ---
> > >   app/test-pmd/cmdline.c | 35 +++++++++++++++++++++++++++++++++++
> > >   1 file changed, 35 insertions(+)
> > > 
> > > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
> > > index d4bb3ec998..1e429e6d0a 100644
> > > --- a/app/test-pmd/cmdline.c
> > > +++ b/app/test-pmd/cmdline.c
> > > @@ -151,6 +151,9 @@ static void cmd_help_long_parsed(void *parsed_result,
> > >   			"quit\n"
> > >   			"    Quit to prompt.\n\n"
> > > +
> > > +			"sleep ms\n"
> > > +			"    Sleep for ms milliseconds.\n\n"
> > >   		);
> > >   	}
> > 
> > A "sleep" command, I would expect to sleep for a certain number of seconds,
> > for compatibility e.g. with terminal "sleep" command.
> > To keep this as "ms" granularity, how about making it explicit as a
> > "sleep_ms" command. Alternatively, how about adding a usleep command? [Not
> > sure "msleep" works, which is why I suggested sleep_ms instead]
> > 
> > /Bruce
> 
> I have no strong opinions on what it should do. My initial version *was* a
> "sleep in seconds" command, I just thought that maybe someone would want it
> more flexible. I suspect that actually "sleep" and second granularity is
> just fine.
> 

I think we do need to support sub-second sleep granularity, though. If we
only add "sleep" with time specified in seconds, I think we'd also need to
add in usleep with micro-sec granularity too.

Other alternatives:
- have sleep take an option 3rd parameter of time in
  minisecond. So "sleep 1" is to sleep for one second, but "sleep 0 500" is
  to sleep for 1/2 sec, and "sleep 2 750" is to sleep for 2.75 seconds.
- add floating point support to the cmdline library, and then allow sleep time
  specified in seconds using that.

/Bruce