On Mon, Nov 03, 2025 at 02:10:56PM -0600, Eric Blake wrote:
> Make it easier to get from the sioc listening to a single address on
> behalf of a NetListener back to its owning object, which will be
> beneficial in an upcoming patch that teaches NetListener how to
> interact with AioContext.
>
> Signed-off-by: Eric Blake <[email protected]>
> ---
> include/io/channel-socket.h | 1 +
> io/channel-socket.c | 1 +
> io/net-listener.c | 1 +
> 3 files changed, 3 insertions(+)
>
> diff --git a/include/io/channel-socket.h b/include/io/channel-socket.h
> index a88cf8b3a9f..eee686f3b4d 100644
> --- a/include/io/channel-socket.h
> +++ b/include/io/channel-socket.h
> @@ -49,6 +49,7 @@ struct QIOChannelSocket {
> socklen_t remoteAddrLen;
> ssize_t zero_copy_queued;
> ssize_t zero_copy_sent;
> + struct QIONetListener *listener;
Commenting on my own patch:
After re-reading docs/devel/style.rst, I can see that this particular
forward declaration of QIONetListener is not consistent with the
guidelines. I have to have a forward reference, since the style guide
also forbids circular inclusion (net-listener.h already includes
channel-socket.h, so channel-socket.h cannot include net-listener.h);
but it may be better for me to move the forward reference into
include/qemu/typedefs.h rather than inlining it how I did here.
(It is a red herring that struct QIOChannelSocket{} already contains
two other uses of 'struct' in its declaration body - both of those are
for 'struct sockaddr_storage' which is the POSIX type always spelled
with struct, with no typical QEMU CamelCase wrapper)
> +++ b/io/channel-socket.c
> @@ -65,6 +65,7 @@ qio_channel_socket_new(void)
> sioc->fd = -1;
> sioc->zero_copy_queued = 0;
> sioc->zero_copy_sent = 0;
> + sioc->listener = NULL;
Also, I added an explicit zero initialization to the new member to
match existing explicit initializers. But checking qom/object.c, I
see that object_new() first uses g_malloc() instead of g_new0(), but
then calls object_initialize_with_type() does a forced memset(,0,) -
so all object constructors that do explicit field initialization to
zero are doing redundant work.
Dropping the sioc->listener = NULL assignment from this patch thus
makes sense from the less work perspective, but now that I've pointed
it out, dropping the sioc->zero_copy_* = 0 lines makes sense too. But
cleanups like that should probably be a separate patch, and maybe
touch as many clients of object_new() as possible (perhaps via
Coccinelle?), rather than shoehorning in a deletion of just those two
lines into a v2 of this particular patch.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization: qemu.org | libguestfs.org
