Re: [PATCH] chardev: add nodelay option

[Daniel P . Berrangé]

On Tue, Mar 02, 2021 at 12:04:44PM +0100, Paolo Bonzini wrote:
> The "delay" option was introduced as a way to enable Nagle's algorithm
> with ",nodelay".  Since the short form for boolean options has now been
> deprecated, introduce a more properly named "nodelay" option.  The "delay"
> option remains as an undocumented option.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  chardev/char-socket.c |  9 +++++++--
>  gdbstub.c             |  2 +-
>  qemu-options.hx       | 14 +++++++-------
>  3 files changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> index 06a37c0cc8..73a7afe5a0 100644
> --- a/chardev/char-socket.c
> +++ b/chardev/char-socket.c
> @@ -1472,8 +1472,13 @@ static void qemu_chr_parse_socket(QemuOpts *opts, 
> ChardevBackend *backend,
>      sock = backend->u.socket.data = g_new0(ChardevSocket, 1);
>      qemu_chr_parse_common(opts, qapi_ChardevSocket_base(sock));
>  
> -    sock->has_nodelay = qemu_opt_get(opts, "delay");
> -    sock->nodelay = !qemu_opt_get_bool(opts, "delay", true);
> +    sock->has_nodelay =
> +        qemu_opt_get(opts, "delay") ||
> +        qemu_opt_get(opts, "nodelay");
> +    sock->nodelay =
> +        !qemu_opt_get_bool(opts, "delay", true) ||
> +        qemu_opt_get_bool(opts, "nodelay", false);

We should raise an explicit error if both options are present,
otherwise you get into a debate about prioritization with nonsense
such as

   -chardev socket,.....,delay=on,nodelay=on


Regards,
Daniel
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