[noPoll] nopoll_conn_new() blocking

[Francis Brosnan Blázquez]

El mié, 09-12-2015 a las 11:15 +0200, Rami Rosenbaum escribió:
> Hello,


Hi Rami,

> 
> I'm using noPoll lib in my Qt GUI application.
> 
> 
> I am using it in non-blocking mode, within my main thread, using
> timer-events and a state machine.
> 
> The scenario happens on both my Ubuntu laptop and my ARM embedded
> Linux.


Ok,

> 
> I just noticed that when my server was down (I'm not sure what that
> means, in networking concepts) - nopoll_conn_new() blocked for its'
> default timeout (20 seconds).
> 
> 
> So
> Question 1: is nopoll_conn_new() blocking?


Ok, yes and no, it is blocking with a timeout but just for sending the
client
init (the initial packet that a WebSocket client must send), but the
function
does not block the caller until a reply from the server is received and
the 
handshake is completed,

So, it essence, nopoll_conn_new (and all its variants) is not blocking
(unless you have a problem with network connection causing send() API
to fail to send the WebSocket init message by returning EWOULD_BLOCK,
which is very likely to not happen),

In that, the connection (noPollConn) reported by this function have big
chances to be not ready (that's why you have to use nopoll_conn_is_ready
or the blocking one nopoll_conn_wait_until_connection_ready to ensure
you successfully connected),


> I found nopoll_conn_connect_timeout(), but it's not in the API.
> 
> 
> So I changed the timeout:
> 
> m_ctx->conn_connect_std_timeout = 2 * 1000 * 1000; // 2 seconds
> 
> 
> and it worked.


Ok, there's a function (nopoll_conn_connect_timeout) which is
already implemented but wasn't on the nopoll_conn.h header.

There's also a nopoll_conn_get_connect_timeout  that also allows
to get current value configured...but again, it was also missing in the
public header,

Now, both are available at the nopoll_conn.h header (please checkout
latest SVN https://github.com/asples/nopoll)


> Question 2: is nopoll_conn_connect_timeout() in the API?


Yes it shouldn't but wasn't declared at the header, 


> 
> Anyway - I can't block my main thread, so what do you recommend?


Ok, you can reduce to the minimum the connect timeout as you did...

..and after nopoll_conn_new finishes, use mentioned functions regularly
to check if you did connect,

Best Regards,


Thanks

> 
> 
> _______________________________________________
> noPoll mailing list
> noPoll en lists.aspl.es
> http://lists.aspl.es/cgi-bin/mailman/listinfo/nopoll


-- 
Francis Brosnan Blázquez  -  ASPL
http://www.asplhosting.com/
http://www.aspl.es/
https://twitter.com/aspl_es
https://twitter.com/asplhosting
https://twitter.com/francisbrosnanb

91 134 14 22 - 91 134 14 45 - 91 116 07 57

AVISO LEGAL
 
En virtud de lo dispuesto en la Ley Orgánica 15/1999, de 13 de
diciembre, de Protección de Datos de Carácter Personal, le informamos de
que sus datos de carácter personal, recogidos de fuentes accesibles al
público o datos que usted nos ha facilitado previamente, proceden de
bases de datos propiedad de Advanced Software Production Line, S.L.
(ASPL).
 
ASPL garantiza que los datos serán tratados con la finalidad de mantener
las oportunas relaciones comerciales o promocionales con usted o la
entidad que usted representa. No obstante, usted puede ejercitar sus
derechos de acceso, rectificación, cancelación y oposición dispuestos en
la mencionada Ley Orgánica, notificándolo por escrito a ASPL -
Protección Datos, C/Antonio Suárez 10 A-102, 28802, Alcalá de Henares
(Madrid).


------------ próxima parte ------------
Se ha borrado un adjunto en formato HTML...
URL: <http://lists.aspl.es/pipermail/nopoll/attachments/20151212/a1662c96/attachment-0001.html>