[PATCH 2/6] app/testpmd: register driver specific commands

[Ferruh Yigit]

On 5/23/2022 8:10 AM, David Marchand wrote:
> +int
> +init_cmdline(void)
> +{
> +       struct testpmd_commands *c;
> +       cmdline_parse_ctx_t *ctx;
> +       unsigned int count = 0;
> +       unsigned int i;
> +
> +       /* initialize non-constant commands */
> +       cmd_set_fwd_mode_init();
> +       cmd_set_fwd_retry_mode_init();
> +
> +       main_ctx = NULL;
> +       for (i = 0; builtin_ctx[i] != NULL; i++) {
> +               ctx = realloc(main_ctx, (count + i + 1) * sizeof(*ctx));
> +               if (ctx == NULL)
> +                       goto err;
> +               main_ctx = ctx;

Instead of 'realloc()', check and assign pointer in each entry, what do 
you think about first calculate the size and alloc once, both for 
'builtin_ctx' & driver specific command?
But of course trade off is to loop twice in that case.

> +               main_ctx[count + i] = builtin_ctx[i];
> +       }

no need to use 'count' in this loop, since it is always '0'.

> +       count += i;
> +
> +       TAILQ_FOREACH(c, &commands_head, next) {
> +               for (i = 0; c->commands[i].ctx != NULL; i++) {
> +                       ctx = realloc(main_ctx, (count + i + 1) * sizeof(*ctx));
> +                       if (ctx == NULL)
> +                               goto err;
> +                       main_ctx = ctx;
> +                       main_ctx[count + i] = c->commands[i].ctx;
> +               }
> +               count += i;
> +       }
> +
> +       /* cmdline expects a NULL terminated array */
> +       ctx = realloc(main_ctx, (count + 1) * sizeof(*ctx));
> +       if (ctx == NULL)
> +               goto err;
> +       main_ctx = ctx;
> +       main_ctx[count] = NULL;
> +       count += 1;

Above block also can be avoided if size calculated in advance.

> +
> +       return 0;
> +err:
> +       free(main_ctx);
> +       return -1;
> +}
> +