Re: [Qemu-devel] [PULL 00/14] Net patches

[Li Zhijian]

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 <address@hidden> 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
>