Re: [Libguestfs] [PATCH libnbd 1/7] api: Add semi-private function for freeing persistent data.

On Mon, Aug 12, 2019 at 01:53:56PM -0500, Eric Blake wrote: > We then have the design question of whether to make an OClosure type, > where C has two functions nbd_aio_pread and nbd_aio_pread_callback for > convenience, but where other languages have only a single nbd.aio_pread > where the callback parameter is optional (the Closure type for > pread_structured chunk and for block_status extent will still be > mandatory; it is only the completion callback that is currently causing > us twice the API because we are treating it as pseudo-optional). Or > maybe we just require C clients of nbd_aio_pread to always provide > parameters for callbacks, but document that the completion callback and > free callback pointers may be NULL. I'll try to see what OClosure (and then getting rid of the _callback variants, adding to the non-callback variants OClosure) will look like tomorrow.