Re: [PATCH v9 02/24] tools lib: Introduce fdarray clone function

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, Jul 02, 2021 at 03:32:10PM +0300, Alexey Bayduraev escreveu:
> Introduce a function to create a copy of an existing file descriptor in
> the fdarray structure. The function returns the position of the copied fd.
> 
> Acked-by: Namhyung Kim <namhyung@gmail.com>
> Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
> ---
>  tools/lib/api/fd/array.c | 17 +++++++++++++++++
>  tools/lib/api/fd/array.h |  1 +
>  2 files changed, 18 insertions(+)
> 
> diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
> index 5e6cb9debe37..de8bcbaea3f1 100644
> --- a/tools/lib/api/fd/array.c
> +++ b/tools/lib/api/fd/array.c
> @@ -88,6 +88,23 @@ int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags
>  	return pos;
>  }
>  
> +int fdarray__clone(struct fdarray *fda, int pos, struct fdarray *base)

The "XX__clone" idiom means "get the XXX instance and get me a clone of
it", i.e. of the whole class, not of an entry, see map__clone(),
evsel__clone(), parse_events_term__clone(), etc.

Please consider:

int fdarray__dup_entry_from(struct fdarray *fda, int pos, struct fdarray *from)

> +{
> +	struct pollfd *entry;
> +	int npos;
> +
> +	if (pos >= base->nr)
> +		return -EINVAL;
> +
> +	entry = &base->entries[pos];
> +
> +	npos = fdarray__add(fda, entry->fd, entry->events, base->priv[pos].flags);
> +	if (npos >= 0)
> +		fda->priv[npos] = base->priv[pos];
> +
> +	return npos;
> +}
> +
>  int fdarray__filter(struct fdarray *fda, short revents,
>  		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
>  		    void *arg)
> diff --git a/tools/lib/api/fd/array.h b/tools/lib/api/fd/array.h
> index 7fcf21a33c0c..4a03da7f1fc1 100644
> --- a/tools/lib/api/fd/array.h
> +++ b/tools/lib/api/fd/array.h
> @@ -42,6 +42,7 @@ struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow);
>  void fdarray__delete(struct fdarray *fda);
>  
>  int fdarray__add(struct fdarray *fda, int fd, short revents, enum fdarray_flags flags);
> +int fdarray__clone(struct fdarray *fda, int pos, struct fdarray *base);
>  int fdarray__poll(struct fdarray *fda, int timeout);
>  int fdarray__filter(struct fdarray *fda, short revents,
>  		    void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
> -- 
> 2.19.0
> 

-- 

- Arnaldo