Re: [PATCH 06/10] hw/core: Add ResetContainer which holds objects implementing Resettable

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 20/2/24 17:06, Peter Maydell wrote:
> Implement a ResetContainer.  This is a subclass of Object, and it
> implements the Resettable interface.  The container holds a list of
> arbitrary other objects which implement Resettable, and when the
> container is reset, all the objects it contains are also reset.
> 
> This will allow us to have a 3-phase-reset equivalent of the old
> qemu_register_reset() API: we will have a single "simulation reset"
> top level ResetContainer, and objects in it are the equivalent of the
> old QEMUResetHandler functions.
> 
> The qemu_register_reset() API manages its list of callbacks using a
> QTAILQ, but here we use a GPtrArray for our list of Resettable
> children: we expect the "remove" operation (which will need to do an
> iteration through the list) to be fairly uncommon, and we get simpler
> code with fewer memory allocations.
> 
> Since there is currently no listed owner in MAINTAINERS for the
> existing reset-related source files, create a new section for
> them, and add these new files there also.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   MAINTAINERS                      | 10 +++++
>   include/hw/core/resetcontainer.h | 48 ++++++++++++++++++++
>   hw/core/resetcontainer.c         | 76 ++++++++++++++++++++++++++++++++
>   hw/core/meson.build              |  1 +
>   4 files changed, 135 insertions(+)
>   create mode 100644 include/hw/core/resetcontainer.h
>   create mode 100644 hw/core/resetcontainer.c


> +static void resettable_container_child_foreach(Object *obj,
> +                                               ResettableChildCallback cb,
> +                                               void *opaque, ResetType type)
> +{
> +    ResettableContainer *rc = RESETTABLE_CONTAINER(obj);
> +    unsigned int len = rc->children->len;
> +
> +    for (unsigned int i = 0; i < len; i++) {

Worth a pair of trace events around the callback call.

> +        cb(g_ptr_array_index(rc->children, i), opaque, type);

> +        /* Detect callbacks trying to unregister themselves */
> +        assert(len == rc->children->len);
> +    }
> +}

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>