Re: [PATCH 3/3] wined3d: Reduce the number of independent heap allocations.

[Henri Verbeet]

On Wed, 29 Sept 2021 at 17:40, Jan Sikorski  wrote:
> dlls/wined3d/cs.c | 56 +++++++++++++++++++++--------------------------
>  1 file changed, 25 insertions(+), 31 deletions(-)

Conceptually I think this is fine, although traditionally we'd use
something like "wined3d: Use a single allocation for command list
data." for the subject line.
> @@ -3735,45 +3730,56 @@ HRESULT CDECL wined3d_deferred_context_record_command_list(struct wined3d_device
>  {
>      struct wined3d_deferred_context *deferred = wined3d_deferred_context_from_context(context);
>      struct wined3d_command_list *object;
> - size_t offset;
> - BYTE *memory;

We'd prefer uint8_t over BYTE here. (More broadly, we prefer standard
types over Windows types inside wined3d.)
You probably need neither "memory" nor "offset" though.
> -
>
> memory = heap_alloc(sizeof(*object) + deferred->resource_count * sizeof(*object->resources) +
> -
>        deferred->upload_count * sizeof(*object->uploads) +
> -
>        deferred->command_list_count * sizeof(*object->command_lists) +
> -
>        deferred->query_count * sizeof(*object->queries) +
> -
>        deferred->data_size);
> -
> -
>
> if (!memory)
>     return E_OUTOFMEMORY;
> -
>
> object = (void *)memory;
> -
>
> offset = sizeof(*object);
> -
>
> memset(object, 0, sizeof(*object));
> -
>
> object->refcount = 1;
>    object->device = deferred->c.device;
> - if (!(object->data = heap_alloc(deferred->data_size)))
> -
>    goto out_free_list;
> - object->data_size = deferred->data_size;
> - memcpy(object->data, deferred->data, deferred->data_size);
> -
> - if (!(object->resources = heap_alloc(deferred->resource_count * sizeof(*object->resources))))
> -
>    goto out_free_data;
> - object->resources = (void *)(memory + offset);
> - offset += deferred->resource_count * sizeof(*object->resources);
> object->resource_count = deferred->resource_count;
> memcpy(object->resources, deferred->resources, deferred->resource_count * sizeof(*object->resources));
> /* Transfer our references to the resources to the command list. */
> - if (!(object->uploads = heap_alloc(deferred->upload_count * sizeof(*object->uploads))))
> -
>    goto out_free_resources;
> - object->uploads = (void *)(memory + offset);
> - offset += deferred->upload_count * sizeof(*object->uploads);
> object->upload_count = deferred->upload_count;
> memcpy(object->uploads, deferred->uploads, deferred->upload_count * sizeof(*object->uploads));
> /* Transfer our references to the resources to the command list. */

We'd typically write that like this:

object = heap_alloc(...);
    ...
    object->resources = (struct wined3d_resource *)&object[1];
    ...
    object->uploads = (struct wined3d_deferred_upload
*)&object->resources[object->resource_count];

etc.