Re: [PATCH] lcore: make semantics of lcore role function more intuitive

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu, 26 Apr 2018 14:56:19 +0000
"Carrillo, Erik G" <erik.g.carrillo@intel.com> wrote:

> Great, thanks Thomas.
> 
> > -----Original Message-----
> > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > Sent: Thursday, April 26, 2018 9:55 AM
> > To: Carrillo, Erik G <erik.g.carrillo@intel.com>
> > Cc: Burakov, Anatoly <anatoly.burakov@intel.com>; dev@dpdk.org; Neil
> > Horman <nhorman@tuxdriver.com>; Mcnamara, John
> > <john.mcnamara@intel.com>; Kovacevic, Marko
> > <marko.kovacevic@intel.com>; Robert Sanford <rsanford@akamai.com>;
> > olivier.matz@6wind.com; shreyansh.jain@nxp.com
> > Subject: Re: [dpdk-dev] [PATCH] lcore: make semantics of lcore role function
> > more intuitive
> > 
> > 26/04/2018 16:44, Carrillo, Erik G:  
> > > Thanks,  Anatoly and Thomas.  I had also considered the following chunk for  
> > the release notes:  
> > >
> > > diff --git a/doc/guides/rel_notes/release_18_05.rst  
> > b/doc/guides/rel_notes/release_18_05.rst  
> > > index 04ff4fe..127a7e2 100644
> > > --- a/doc/guides/rel_notes/release_18_05.rst
> > > +++ b/doc/guides/rel_notes/release_18_05.rst
> > > @@ -72,6 +72,11 @@ API Changes
> > >     Also, make sure to start the actual text at the margin.
> > >  
> > =========================================================  
> > >
> > > +* **rte_lcore_has_role() return values changed**
> > > +
> > > +  This function now returns 1 or 0 for true or false, respectively, rather
> > > +  than 0 or <0 for success or failure to make use of the function more
> > > +  intuitive.
> > >
> > >  ABI Changes
> > >  -----------
> > >
> > > Do we want this note?  Also, it looks like the Doxygen documentation of  
> > the function in the header file didn't get updated.
> > 
> > 
> > Oh, you are right, this patch is not complete.
> > I've fixed it:
> > 
> > --- a/doc/guides/rel_notes/release_18_05.rst
> > +++ b/doc/guides/rel_notes/release_18_05.rst
> > @@ -161,6 +161,12 @@ API Changes
> >    announced at least one release before the ABI change is made. There are
> > no
> >    ABI breaking changes planned.
> > 
> > +* eal: ``rte_lcore_has_role()`` return value changed.
> > +
> > +  This function now returns true or false, respectively, rather  than 0
> > + or <0 for success or failure.
> > +  It makes use of the function more intuitive.
> > +
> >  * mempool: capability flags and related functions have been removed.
> > 
> >    Flags ``MEMPOOL_F_CAPA_PHYS_CONTIG`` and diff --git
> > a/lib/librte_eal/common/include/rte_lcore.h
> > b/lib/librte_eal/common/include/rte_lcore.h
> > index 334a0629e..1a2f37eaa 100644
> > --- a/lib/librte_eal/common/include/rte_lcore.h
> > +++ b/lib/librte_eal/common/include/rte_lcore.h
> > @@ -311,7 +311,7 @@ rte_ctrl_thread_create(pthread_t *thread, const char
> > *name,
> >   * @param role
> >   *   The role to be checked against.
> >   * @return
> > - *   On success, return 0; otherwise return a negative value.
> > + *   Boolean value: positive if test is true; otherwise returns 0.
> >   */
> > 
> > Thanks Erik!
> >   
> 

Usually the  safest way to introduce this is introduce a new function
with a different name. Then retire the old one.