Re: [RFC PATCH v2 7/8] graph-lock: implement WITH_GRAPH_RDLOCK_GUARD and GRAPH_RDLOCK_GUARD macros

[Stefan Hajnoczi]

On Tue, Apr 26, 2022 at 04:51:13AM -0400, Emanuele Giuseppe Esposito wrote:
> Similar to the implementation in lockable.h, implement macros to
> automatically take and release the rdlock.
> Create the empty GraphLockable struct only to use it as a type for
> G_DEFINE_AUTOPTR_CLEANUP_FUNC.
> 
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
>  include/block/graph-lock.h | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/include/block/graph-lock.h b/include/block/graph-lock.h
> index 2211d41286..8d8a6513f1 100644
> --- a/include/block/graph-lock.h
> +++ b/include/block/graph-lock.h
> @@ -67,5 +67,35 @@ void assert_bdrv_graph_readable(void);
>   */
>  void assert_bdrv_graph_writable(void);
>  
> +typedef struct GraphLockable { } GraphLockable;
> +
> +#define GML_OBJ_() (&(GraphLockable) { })

The comment for QML_OBJ_() is helpful. This takes advantage of the
lifetime of compound literals and it's different in C and C++. I suggest
keeping it for the benefit for people trying to understand how this
works.

signature.asc
Description: PGP signature