Re: [Tarantool-patches] [PATCH 5/7] box/error: clarify purpose of reference counting in struct error

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Thanks for the patch!

How about merging this commit into the previous one?

On 19/02/2020 15:16, Nikita Pettik wrote:
> ---
>  src/lib/core/diag.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/src/lib/core/diag.h b/src/lib/core/diag.h
> index 5271733cb..a9181c522 100644
> --- a/src/lib/core/diag.h
> +++ b/src/lib/core/diag.h
> @@ -72,6 +72,15 @@ struct error {
>  	error_f raise;
>  	error_f log;
>  	const struct type_info *type;
> +	/**
> +	 * Reference counting is basically required since
> +	 * instances of this structure are available in Lua
> +	 * as well (as cdata with overloaded fields and methods
> +	 * by the means of introspection). Thus, it may turn
> +	 * out that Lua's GC attempts at releasing object
> +	 * meanwhile it is still used in C internals or vice
> +	 * versa. For details see luaT_pusherror().

Hmm, no, it can't anymore. Lua can't delete an error object,
if it is still used in C. This looks like an artifact from the
previous patch version, were you unreferenced all errors when
diag was cleared.

> +	 */
>  	int refs;
>  	/**
>  	 * Errno at the moment of the error
>