[lwip-users] problem tcp_enqueue

[Nicolas Dioli]

Hello everybody,
I have a problem with RAW API.
I have a memory error when i do a tcp_enqueue() after 70 bytes.
here is my code:

                    for(i=0;i<6;i++){
                        tcp_write(tcp1, "1234567890" , 10, 
TCP_WRITE_FLAG_COPY);    //No error
                        tempo_ms(50);
                    }
                    tcp_output(tcp1);                                
                                                        //60 bytes sent
                    err=tcp_write(tcp1, "ABCDEFGHIJ" , 10, 
TCP_WRITE_FLAG_COPY);  //No error
                    err=tcp_output(tcp1);                            
                                                        //10 bytes sent
                    err=tcp_write(tcp1, "1234567890" , 10, 
TCP_WRITE_FLAG_COPY);        //MEM_ERROR
                    err=tcp_output(tcp1);


I think there is no free memory after output because of that:
        #define TCP_SND_QUEUELEN                (8 * 
(TCP_SND_BUF)/(TCP_MSS)) = 8*512/536 =7.6
So when i arrived at this test:
        /* check for configured max queuelen and possible overflow */
          if ((queuelen >= TCP_SND_QUEUELEN) || (queuelen > 
TCP_SNDQUEUELEN_OVERFLOW)) {
i have a queuelen of 7 and i return an ERR_MEM.