From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:50011)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <anthony@codemonkey.ws>) id 1UK6mQ-0003Tr-CY
	for qemu-devel@nongnu.org; Mon, 25 Mar 2013 08:45:40 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <anthony@codemonkey.ws>) id 1UK6mO-0002iP-Oz
	for qemu-devel@nongnu.org; Mon, 25 Mar 2013 08:45:38 -0400
Received: from mail-ia0-x231.google.com ([2607:f8b0:4001:c02::231]:52179)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <anthony@codemonkey.ws>) id 1UK6mO-0002iF-L3
	for qemu-devel@nongnu.org; Mon, 25 Mar 2013 08:45:36 -0400
Received: by mail-ia0-f177.google.com with SMTP id w33so2269342iag.8
	for <qemu-devel@nongnu.org>; Mon, 25 Mar 2013 05:45:35 -0700 (PDT)
From: Anthony Liguori <anthony@codemonkey.ws>
In-Reply-To: <1364128793-12689-4-git-send-email-hdegoede@redhat.com>
References: <1364128793-12689-1-git-send-email-hdegoede@redhat.com>
	<1364128793-12689-4-git-send-email-hdegoede@redhat.com>
Date: Mon, 25 Mar 2013 07:45:09 -0500
Message-ID: <87d2unodgq.fsf@codemonkey.ws>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Subject: Re: [Qemu-devel] [PATCH 3/8] qemu-char: Add fe_open tracking
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Hans de Goede <hdegoede@redhat.com>, qemu-devel@nongnu.org
Cc: Amit Shah <amit.shah@redhat.com>

Hans de Goede <hdegoede@redhat.com> writes:

> Add tracking of the fe_open state to struct CharDriverState.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  include/char/char.h | 1 +
>  qemu-char.c         | 2 ++
>  2 files changed, 3 insertions(+)
>
> diff --git a/include/char/char.h b/include/char/char.h
> index dd8f39a..3174575 100644
> --- a/include/char/char.h
> +++ b/include/char/char.h
> @@ -75,6 +75,7 @@ struct CharDriverState {
>      char *label;
>      char *filename;
>      int be_open;
> +    int fe_open;
>      int avail_connections;
>      QemuOpts *opts;
>      QTAILQ_ENTRY(CharDriverState) next;
> diff --git a/qemu-char.c b/qemu-char.c
> index 55795d7..554d72f 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -3385,6 +3385,7 @@ void qemu_chr_fe_set_echo(struct CharDriverState *chr, bool echo)
>  
>  void qemu_chr_fe_open(struct CharDriverState *chr)
>  {
> +    chr->fe_open = 1;
>      if (chr->chr_guest_open) {
>          chr->chr_guest_open(chr);
>      }
> @@ -3392,6 +3393,7 @@ void qemu_chr_fe_open(struct CharDriverState *chr)
>  
>  void qemu_chr_fe_close(struct CharDriverState *chr)
>  {
> +    chr->fe_open = 0;

Even though this gets rewritten later on, you should avoid calling the
callback when open is called when fe_open=1.  Something like

if (!chr->fe_open) {
    return;
}

Then later when this becomes set_fe_open() the backend doesn't need to
deal with double open/close.

Regards,

Anthony Liguori

>      if (chr->chr_guest_close) {
>          chr->chr_guest_close(chr);
>      }
> -- 
> 1.8.1.4