[PATCH wayland 2/6] Add wl_resource_init and use it in libwayland implementations of data sharing and SHM

[Kristian Høgsberg]

On Fri, Mar 08, 2013 at 10:26:13PM -0600, Jason Ekstrand wrote:
> This commit adds a wl_resource_init function for initializing wl_resource
> structures similar to wl_client_add_object.
> 
> From this commit forward, wl_resource structures should not be initialized
> manually, but should use wl_resource_init.  In the event of a change to the
> wl_resource structure, this allows us to protect against regressions by filling
> in added fields with reasonable defaults.  In this way, while changing
> wl_object or wl_resource still constitutes an ABI break, compositors following
> this rule will only need to be recompiled in order to properly link against the
> new version.

I'm wondering if we should just make all wl_resource instances
malloced and just use wl_client_add_object() and
wl_client_new_object().  That will also allow us to allocate the
wl_resource in the demarshal code for new_id arguments.  It's a little
bit more memory fragmentation and pointer jumping, but I doubt that
will ever be an issue...

Kristian

> Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
> ---
>  src/data-device.c    | 16 ++++------------
>  src/wayland-server.c |  6 +-----
>  src/wayland-server.h | 16 ++++++++++++++++
>  src/wayland-shm.c    | 24 ++++++------------------
>  4 files changed, 27 insertions(+), 35 deletions(-)
> 
> diff --git a/src/data-device.c b/src/data-device.c
> index 4255c13..92ceb12 100644
> --- a/src/data-device.c
> +++ b/src/data-device.c
> @@ -98,13 +98,9 @@ wl_data_source_send_offer(struct wl_data_source *source,
>  	if (offer == NULL)
>  		return NULL;
>  
> +	wl_resource_init(&offer->resource, &wl_data_offer_interface,
> +			 &data_offer_interface, 0, offer);
>  	offer->resource.destroy = destroy_data_offer;
> -	offer->resource.object.id = 0;
> -	offer->resource.object.interface = &wl_data_offer_interface;
> -	offer->resource.object.implementation =
> -		(void (**)(void)) &data_offer_interface;
> -	offer->resource.data = offer;
> -	wl_signal_init(&offer->resource.destroy_signal);
>  
>  	offer->source = source;
>  	offer->source_destroy_listener.notify = destroy_offer_data_source;
> @@ -459,13 +455,9 @@ create_data_source(struct wl_client *client,
>  		return;
>  	}
>  
> +	wl_resource_init(&source->resource, &wl_data_source_interface,
> +			 &data_source_interface, id, source);
>  	source->resource.destroy = destroy_data_source;
> -	source->resource.object.id = id;
> -	source->resource.object.interface = &wl_data_source_interface;
> -	source->resource.object.implementation =
> -		(void (**)(void)) &data_source_interface;
> -	source->resource.data = source;
> -	wl_signal_init(&source->resource.destroy_signal);
>  
>  	source->accept = client_source_accept;
>  	source->send = client_source_send;
> diff --git a/src/wayland-server.c b/src/wayland-server.c
> index 130511d..dcb4435 100644
> --- a/src/wayland-server.c
> +++ b/src/wayland-server.c
> @@ -1396,13 +1396,9 @@ wl_client_add_object(struct wl_client *client,
>  		return NULL;
>  	}
>  
> -	resource->object.interface = interface;
> -	resource->object.implementation = implementation;
> -	resource->object.id = id;
> +	wl_resource_init(resource, interface, implementation, id, data);
>  	resource->client = client;
> -	resource->data = data;
>  	resource->destroy = (void *) free;
> -	wl_signal_init(&resource->destroy_signal);
>  
>  	if (wl_map_insert_at(&client->objects, resource->object.id, resource) < 0) {
>  		wl_resource_post_error(client->display_resource,
> diff --git a/src/wayland-server.h b/src/wayland-server.h
> index c7369eb..38b8303 100644
> --- a/src/wayland-server.h
> +++ b/src/wayland-server.h
> @@ -190,6 +190,22 @@ struct wl_resource {
>  	void *data;
>  };
>  
> +static inline void
> +wl_resource_init(struct wl_resource *resource,
> +		 const struct wl_interface *interface,
> +		 const void *implementation, uint32_t id, void *data)
> +{
> +	resource->object.id = id;
> +	resource->object.interface = interface;
> +	resource->object.implementation = implementation;
> +
> +	wl_signal_init(&resource->destroy_signal);
> +
> +	resource->destroy = NULL;
> +	resource->client = NULL;
> +	resource->data = data;
> +}
> +
>  struct wl_buffer {
>  	struct wl_resource resource;
>  	int32_t width, height;
> diff --git a/src/wayland-shm.c b/src/wayland-shm.c
> index 47c126b..776c0f2 100644
> --- a/src/wayland-shm.c
> +++ b/src/wayland-shm.c
> @@ -128,12 +128,8 @@ shm_pool_create_buffer(struct wl_client *client, struct wl_resource *resource,
>  	buffer->pool = pool;
>  	pool->refcount++;
>  
> -	buffer->buffer.resource.object.id = id;
> -	buffer->buffer.resource.object.interface = &wl_buffer_interface;
> -	buffer->buffer.resource.object.implementation = (void (**)(void))
> -		&shm_buffer_interface;
> -
> -	buffer->buffer.resource.data = buffer;
> +	wl_resource_init(&buffer->buffer.resource, &wl_buffer_interface,
> +			 &shm_buffer_interface, id, buffer);
>  	buffer->buffer.resource.client = resource->client;
>  	buffer->buffer.resource.destroy = destroy_buffer;
>  
> @@ -211,12 +207,8 @@ shm_create_pool(struct wl_client *client, struct wl_resource *resource,
>  	}
>  	close(fd);
>  
> -	pool->resource.object.id = id;
> -	pool->resource.object.interface = &wl_shm_pool_interface;
> -	pool->resource.object.implementation =
> -		(void (**)(void)) &shm_pool_interface;
> -
> -	pool->resource.data = pool;
> +	wl_resource_init(&pool->resource, &wl_shm_pool_interface,
> +			 &shm_pool_interface, id, pool);
>  	pool->resource.client = client;
>  	pool->resource.destroy = destroy_pool;
>  
> @@ -283,12 +275,8 @@ wl_shm_buffer_create(struct wl_client *client,
>  	buffer->offset = 0;
>  	buffer->pool = NULL;
>  
> -	buffer->buffer.resource.object.id = id;
> -	buffer->buffer.resource.object.interface = &wl_buffer_interface;
> -	buffer->buffer.resource.object.implementation = (void (**)(void))
> -		&shm_buffer_interface;
> -
> -	buffer->buffer.resource.data = buffer;
> +	wl_resource_init(&buffer->buffer.resource, &wl_buffer_interface,
> +			 &shm_buffer_interface, id, buffer);
>  	buffer->buffer.resource.client = client;
>  	buffer->buffer.resource.destroy = destroy_buffer;
>  
> -- 
> 1.8.1.4
> 
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