Re: [dpdk-dev] [PATCH v4 1/4] mempool: add event callbacks

[Dmitry Kozlyuk <dkozlyuk@oss.nvidia.com>]

> -----Original Message-----
> From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> [...]
> With below review notes processed
> 
> Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> 

Thanks for the comments, I'll fix them all, just a small note below FYI.

> > +     rte_mcfg_mempool_read_lock();
> > +     rte_mcfg_tailq_write_lock();
> > +     ret = -ENOENT;
> > +     list = RTE_TAILQ_CAST(callback_tailq.head, mempool_callback_list);
> > +     TAILQ_FOREACH(te, list, next) {
> > +             cb = (struct mempool_callback *)te->data;
> > +             if (cb->func == func && cb->user_data == user_data)
> > +                     break;
> > +     }
> > +     if (te != NULL) {
> 
> Here we rely on the fact that TAILQ_FOREACH() exists with te==NULL in the
> case of no such entry. I'd suggest to avoid the assumption.
> I.e. do below two lines above before break and have not the if condition
> her at all.

Since you asked the question, the code is non-obvious, so I'll change it.
FWIW, man 3 tailq:

    TAILQ_FOREACH() traverses the queue referenced by head in the forward
    direction, assigning each element in turn to var.  var is set to NULL
    if the loop completes normally, or if there were no elements.