Anonymous structs in DPDK

[Stephen Hemminger]

On Tue, 13 Dec 2022 13:55:10 +0000
Ferruh Yigit <ferruh.yigit at amd.com> wrote:

> On 12/13/2022 12:51 PM, Antonio Di Bacco wrote:
> > I noticed that DPDK include files have a number of anonymous/unnamed struct:
> > 
> > For example:
> > 
> > /**
> >  * The rte_spinlock_t type.
> >  */
> > typedef struct {
> >         volatile int locked; /**< lock status 0 = unlocked, 1 = locked */
> > } rte_spinlock_t;
> > 
> > This choice doesn't allow to use forward declaration. I need forward
> > declaration because I'm using a rte_spinlock_t pointer in a C++ class
> > and I don't want to include rte_spinlock.h to prevent my application
> > to include it as well.
> > 
> > Is there any reason to use unnamed structures?
> >   
> 
> Hi Antonio Di,
> 
> I don't think there is a specific reason to not use named struct, I
> assume that is only because there was no need to have it.
> 
> So if you need, you can send a simple patch to convert anonymous struct
> to named struct, although I am not clear why you can't include
> 'rte_spinlock.h' in the file you declare your class.
> 
> Cheers,
> ferruh

Why not include rte_spinlock.h? Spinlocks are meant to be embedded
in the object using it. Using spinlocks by reference adds more space
and causes a cache miss.