[lwip-users] LWIP RAW API tcpip_callback()

[Werner Motz]

Hello,

I am using lwip 2.0.2 RAW API + freertos 8.2.3

I am able to establish a connection and I can receive data

without any problems.

 

I would like to know what is the best way to send data outside

the lwip thread.

 

In my freertos task (outside lwip) I do following:

 

void SEND_TASK(void *pvParameters)

{

       portTickType xLastWakeTime;

       const portTickType xFrequency = SEND_CYCLE_TIME_MS; //100ms

       xLastWakeTime = xTaskGetTickCount();

 

       //------------------TASK-----------------------

      

       for(;;)

       {

             tcpip_callback_with_block(WTF, tcp_active_pcbs, 0);

             vTaskDelayUntil(&xLastWakeTime, xFrequency); //Pause

       }

}

 

 

void WTF(void* arg)

{           

       struct tcp_pcb *pcb = (struct tcp_pcb*) arg;

       char ucrecBuff[44] = {0x88};

      

       pcb->flags |= (TF_NODELAY);

            

       tcp_write(pcb, ucrecBuff, 44, TCP_WRITE_FLAG_COPY);

      

       tcp_output(pcb);

}

 

 

Unfortunatelly I run into Assert function in tcpip_callback_with_block(…)

 

LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));

 

Does anybody know what I am doing wrong? I know that the RAW api is not for

Multithreading issues. But I am sure u know a way J  

Is it legit to call tcpip_callback_with_block(..) outside the lwip thread?

What would be the proper architecture to send data? In the examples I only saw

callback echo servers but I do not want to write data only after receiving some J

I am looking forward to your help.