Re: [Qemu-devel] [PATCH for-2.7 2/2] net: make socket connect non-blocking again

[Cao jin <caoj.fnst@cn.fujitsu.com>]

Hi,
I just noticed you still using the old-style non-blocking connect(which 
will still block when query DNS), which will be removed (suggested by 
Daniel), but the patch is still on the way. So I guess maybe you should 
switch to QIOChannel way.

FYI:
http://lists.nongnu.org/archive/html/qemu-devel/2016-07/msg06386.html
http://lists.nongnu.org/archive/html/qemu-devel/2016-08/msg00046.html

     Cao jin

On 08/23/2016 05:45 PM, Marc-André Lureau wrote:
> Since commit 7e8449594c929, the socket connect code is blocking, because
> calling socket_connect() without callback is blocking. Make it
> non-blocking by adding a callback. Unfortunately, the callback needs
> many local variables that are not easy to get rid of (it can't easily
> create the qemu_new_net_client() earlier). By adding the callback, the
> socket is also made non-blocking. If the socket attempt succeeded
> immediately, the callback is still being called.
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>   net/socket.c | 82 +++++++++++++++++++++++++++++++++++++++---------------------
>   1 file changed, 53 insertions(+), 29 deletions(-)
>

> +
> +static int net_socket_connect_init(NetClientState *peer,
> +                                   const char *model,
> +                                   const char *name,
> +                                   const char *host_str)
> +{
> +    socket_connect_data *c = g_new0(socket_connect_data, 1);
> +    int fd = -1;
> +    Error *local_error = NULL;
> +
> +    c->peer = peer;
> +    c->model = g_strdup(model);
> +    c->name = g_strdup(name);
> +    c->saddr = socket_parse(host_str, &local_error);
> +    if (c->saddr == NULL) {
> +        goto err;
> +    }
> +
> +    fd = socket_connect(c->saddr, &local_error, net_socket_connected, c);
> +    if (fd < 0) {
> +        goto err;
> +    }
> +
> +    return 0;
> +
> +err:
> +    error_report_err(local_error);
> +    socket_connect_data_free(c);
> +    return -1;
>   }
>
>   static int net_socket_mcast_init(NetClientState *peer,
>