Re: [Tarantool-patches] [PATCH 1/1] fiber: extend max fiber name length to 255

[Cyrill Gorcunov <gorcunov@gmail.com>]

On Sat, Mar 14, 2020 at 04:16:35PM +0100, Vladislav Shpilevoy wrote:
> Users keep complaining about too short fiber name. New limit is
> 255, should be enough for any sane name.
> 
> Closes #4394
> 
>  fiber_set_name(struct fiber *fiber, const char *name)
>  {
> -	assert(name != NULL);
> -	snprintf(fiber->name, sizeof(fiber->name), "%s", name);
> +	size_t len = MIN(strlen(name), FIBER_NAME_MAX);
> +	char *new_name = realloc(fiber->name, len + 1);

I don't like it completely. The fiber cache has been made
not just to eliminate new memory allocation but also to
reduce memory fragmentation and now we give a user a hand
to shuffle memory in easy path :(

If 32 bytes is really not enough lest make it 64 (or 128)
and allocate together with fiber cache.

> +	if (new_name == NULL)
> +		panic("fiber_set_name() can't fail");
> +	fiber->name = new_name;
> +	memcpy(new_name, name, len);
> +	new_name[len] = 0;