[DTrace-devel] [PATCH 2/7] Implement the sched provider

[Eugene Loh]

Sorry, another question:

On 5/9/23 18:29, Kris Van Hees via DTrace-devel wrote:
> +static int probe_info(dtrace_hdl_t *dtp, const dt_probe_t *prp,
> +		      int *argcp, dt_argdesc_t **argvp)
> +{
> +	int		i;
> +	int		pidx = -1;
> +	int		argc = 0;
> +	dt_argdesc_t	*argv = NULL;
> +
> +	for (i = 0; i < ARRAY_SIZE(probe_args); i++) {
> +		probe_arg_t	*arg = &probe_args[i];
> +
> +		if (strcmp(arg->name, prp->desc->prb) == 0) {
> +			if (pidx == -1) {
> +				pidx = i;
> +
> +				if (arg->argdesc.native == NULL)
> +					break;

What is the argdest.native check all about?  Is it necessary for 
correctness?  A vestigial check?  An attempt to optimize (short-circuit 
the loop)?

> +			}
> +
> +			argc++;
> +		}
> +	}
> +
> +	if (argc == 0)
> +		goto done;
> +
> +	argv = dt_zalloc(dtp, argc * sizeof(dt_argdesc_t));
> +	if (!argv)
> +		return -ENOMEM;
> +
> +	for (i = pidx; i < pidx + argc; i++) {
> +		probe_arg_t	*arg = &probe_args[i];
> +
> +		argv[arg->argno] = arg->argdesc;
> +	}
> +
> +done:
> +	*argcp = argc;
> +	*argvp = argv;
> +
> +	return 0;
> +}