From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:52047)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <lizhijian@cn.fujitsu.com>) id 1adrdZ-0001wp-2u
	for qemu-devel@nongnu.org; Wed, 09 Mar 2016 22:51:46 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <lizhijian@cn.fujitsu.com>) id 1adrdW-0000Tn-Ar
	for qemu-devel@nongnu.org; Wed, 09 Mar 2016 22:51:45 -0500
Received: from [59.151.112.132] (port=46810 helo=heian.cn.fujitsu.com)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <lizhijian@cn.fujitsu.com>) id 1adrdV-0000SY-RV
	for qemu-devel@nongnu.org; Wed, 09 Mar 2016 22:51:42 -0500
From: Li Zhijian <lizhijian@cn.fujitsu.com>
References: <1457320380-5111-1-git-send-email-jasowang@redhat.com>
	<CAFEAcA-7+pZFO6_p-w_95BB1fmU9hVdV-Z6V_xqyqOfOQ+ktgQ@mail.gmail.com>
	<56DE802F.2060502@redhat.com> <56DE8436.60304@cn.fujitsu.com>
	<56DE859B.8020404@redhat.com> <56DE9630.5020109@cn.fujitsu.com>
	<CAFEAcA8_cnxjT7Yh7TgD9BR28PUb8Z6AXKpVMFhadwbwtMXOaQ@mail.gmail.com>
	<56E0DBBF.8060703@redhat.com>
Message-ID: <56E0EF3D.8070404@cn.fujitsu.com>
Date: Thu, 10 Mar 2016 11:51:25 +0800
MIME-Version: 1.0
In-Reply-To: <56E0DBBF.8060703@redhat.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PULL 00/14] Net patches
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: Jason Wang <jasowang@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>



On 03/10/2016 10:28 AM, Jason Wang wrote:
>
>
> On 03/08/2016 05:54 PM, Peter Maydell wrote:
>> On 8 March 2016 at 16:06, Zhang Chen <zhangchen.fnst@cn.fujitsu.com> wrote:
>>> I found the reason for this problem is that
>>> unix_connect() have not connect to sock_path before iov_send().
>>> It need time to establish connection. so can we fix it with usleep()
>>> like this:
>>>
>>>      recv_sock = unix_connect(sock_path, NULL);
>>>      g_assert_cmpint(recv_sock, !=, -1);
>>> +    usleep(1000);
>>>
>>>      ret = iov_send(send_sock[0], iov, 2, 0, sizeof(size) +
>>> sizeof(send_buf));
>>>      g_assert_cmpint(ret, ==, sizeof(send_buf) + sizeof(size));
>>>      close(send_sock[0]);
>>>
>>>      ret = qemu_recv(recv_sock, &len, sizeof(len), 0);
>> I would prefer it if we could find a way to fix this race
>> reliably rather than just inserting a delay and hoping it
>> is sufficient. Otherwise the test is likely to be unreliable
>> if run on a heavily loaded or slow machine.
>>
>> thanks
>> -- PMM
>>
>
> +1
>
> To make sure the connected socket to be proceeded before iov_send(), you
> could use some like  qmp("{ 'execute' : 'query-status'}") before
> iov_send(). With this we are guaranteed that connected is setting to
> true before iov_send().
>
>

it seem works, but i don't know.
Is this because that both qemu accepting the connection and qmp command are working under *iothread*,
so that when the qemu command returns, we can guaranteed the connection is accepted ?

Thanks
Li Zhijian
>
>
>