io: check there are no qio_channel_yield() coroutines during ->finalize()

Callers must clean up their coroutines before calling
object_unref(OBJECT(ioc)) to prevent an fd handler leak. Add an
assertion to check this.

This patch is preparation for the fd handler changes that follow.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230830224802.493686-4-stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
1 file changed