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

["Morten Brørup" <mb@smartsharesystems.com>]

> From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> Sent: Friday, 2 May 2025 16.44
> 
> 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

"sleep" should take one parameter: seconds.

It can be float, or a separate "usleep" command taking a microseconds parameter can be added. This change (using float instead of int) or addition (usleep command) can be added later, if you like.

Initially, I would lean towards a float parameter, but maybe it's easier for scripts to use "usleep" with an integer.
In real life, the duration will probably be either "N" (i.e. a natural number) or "0.N" (i.e. less than one second), so an "usleep" might be just as good.