[lwip-users] porting vnc server FreeRTOS&lwip

PHAM ANH THIEN

unread,

Mar 3, 2010, 4:52:38 AM3/3/10

to Mailing list for lwIP users

Dear all,

Has anyone ported vnc server to FreeRTOS & lwip stack? could you please share it with me?

thanks and best regards,
Thien

Nicolas Pinault

unread,

Mar 4, 2010, 2:53:50 AM3/4/10

to Mailing list for lwIP users

Hi,

Dear all,

Has anyone ported vnc server to FreeRTOS & lwip stack? could you please share it with me?

There is a basic vnc server sample code in ecos cvs tree here : http://ecos.sourceware.org/cgi-bin/cvsweb.cgi/ecos-opt/net/net/vnc_server/current/?cvsroot=ecos
This code can easily be ported to any
I recommend using TightVNC as a viewer.

Regards,
Nicolas

thanks and best regards,
Thien


_______________________________________________
lwip-users mailing list
lwip-...@nongnu.org
http://lists.nongnu.org/mailman/listinfo/lwip-users

PHAM ANH THIEN

unread,

Mar 4, 2010, 2:59:11 AM3/4/10

to nico...@aaton.com, Mailing list for lwIP users

hi Nicolas,

thanks a lot. I will check it.

kind regards,
Thien

Nicolas Pinault

unread,

Mar 4, 2010, 7:09:28 AM3/4/10

to Mailing list for lwIP users

Thien,

Be careful that, with lwip, it is not safe to access the same socket with 2 tasks (as it is done in the sample code).

Regards,
Nicolas

Nicolas Pinault

unread,

Sep 15, 2010, 2:54:56 AM9/15/10

to lwip-...@nongnu.org

Hi Thien,

hi Nicolas,

I can access the same socket with 2 tasks in lwip, what's the problem did you mention?

Yes, it works. Or, I shall say it seems to work. Lwip is not thread safe. Accessing the same socket in two different threads is not safe. Your system will bug/hang/crash sooner or later.
This means you have to modify the original code.

Anyone to know vnc server can actively send FrameBufferUpdate command to vnc client (without receiving FrameBufferUpdate Request command from client) to inform client that the screen of server was changed?

The server always sends screen data when it wants/needs to. The server may send only part of screen data that have changed.
The client can request a screen update when needed. At startup for example.

Vnc protocol is simple. You can find the reference document here : http://www.realvnc.com/docs/rfbproto.pdf
As a client, I recommend using ThighVnc 1.3.10 as it is simple (http://www.tightvnc.com/download.php). Configure viewer to suit server settings.
At the opposite, UltraVnc tries to find server settings automatically but this does not work correctly with the code I use.

Regards,
Nicolas

thanks and best regards,
Thien

Simon Goldschmidt

unread,

Sep 15, 2010, 11:30:00 AM9/15/10

to Mailing list for lwIP users

PHAM ANH THIEN wrote:

The fail or success of accessing same socket on 2 thread is depend on OS, which lwip ported on. If that OS support multi task/process/thread, i think it is ok. Am i right?

Just to clarify this (as in the link Martin already wrote): this is NOT true,sockets generally can't be used by more than one application thread! This is a limitation of the lip core, not the OS port.

Simon

Giorgio Colazzo

unread,

Oct 30, 2023, 8:23:13 AM10/30/23

to osdeve.mirror.tcpip.lwip

Hi all,

could you please resend the code in a working link?

thanks in advance.

Really appreciated.

Regards

Reply all

Reply to author

Forward