Re: [lwip-users] Possible to have netconn_recv unblocking?

[Yann Suisini]

Maybe a good idea could be have the same feature when sending data :
a ->recv_timeout field , either 0 for blocking or another valuer when you
want a timeout on a sent packet but non acknowledged (or an unsent packet
due to memory or other error).

This way we could choss for a fully blocking or non blockin netconn ! :-)

Yann.



DownyTif wrote:
> 
> ok, maybe I posted my question a little early. I figured it out and it's
> working fine. For the record, here is what I did:
> 1- Changed LWIP_SO_RCVTIMEO  to '1';
> 2- Since I want to "netconn_accept()" call to be blocking, I did this,
> where
> pNetConnListener is a struct netconn*:
> 
> // Put a timeout of 0 to force a blocking accept.
> pNetConnListener->recv_timeout = 0;
> pNetConnListenerNewConn = netconn_accept(pNetConnListener);
> 
> 3- Since I want a non-blocking "netconn_recv()", I did this:
> 
> // Check for incoming frames.
> pNetConnListenerNewConn->recv_timeout = receiveTimeoutInMs;
> pNetBuffer = netconn_recv(pNetConnListenerNewConn);
> if (pNetBuffer != NULL)
> {
>     .......
> }
> else
> {
>     // Detect if there was a problem or it's because there was no data.
>     if (pNetConnListenerNewConn->err == ERR_TIMEOUT)
>     {
>         // No data received. Since we should receive a keep alive packet
> every x seconds,
>         // this mean that the host has a problem or the connection has
> been
> broken
>         // (disconnected cable for example). Disconnect and prepare for
> next
> connection.
>         break;
>     }
>     else
>     {
>         // For any other errors, it's a problem. Disconnect and prepare
> for
> next connection.
>         //print_dbg("CommManager - ListenerTask Connection Problem.\n\r");
>         break;
>     }
> }
> 
> My search of LWIP_SO_RCVTIMEO indicated that it's not used anywhere else
> that needs attention (except for the netconn_accept()). So, now I can
> disconnect and reconnect my cable at will!
> 
> Hope this helps some others!
> 
> 
> 
> 
> On Fri, Oct 2, 2009 at 11:44 AM, Dany Thiffeault
> <address@hidden>wrote:
> 
>> Hey,
>> I was testing the stability of my system, so I disconnected the Ethernet
>> cable from my lwIP device and reconnected it. I found out that the
>> connection wasn't re-initializing itself. I foudn out that my task is
>> blocked in netconn_recv() indefinatly.
>>
>> I absolutly need to be able to detect a network fault and go back into
>> connection accepting state. I searched around and found threads about
>> this
>> exact question, but the replies were all: swith to raw API.
>>
>> This is not good for me, since I'm using a multi-task system with RTOS,
>> sequential API.
>>
>> My LWIP_SO_RCVTIMEO is 0 currently, and according to the code, it looks
>> like I could put this to 1 and not block. But I just want to use it on
>> the netconn_recv()
>> call, no others...
>>
>> Any advice here? Is it the way to go?
>> Thanks!
>>
> 
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> 

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