lwip Out of Memory Error

Jo-Jo Smith

Other Parts Discussed in Thread: EK-TM4C1294XL

I have created a TCP client on an EK-TM4C1294XL board. I can connect to my server, and receive data just fine, but I can't send data. Here is the code I am using to send data:

            p_pcb = tcp_new();
           returnError = tcp_bind(p_pcb, IP_ADDR_ANY, LOCAL_PORT);

           returnError = tcp_connect(p_pcb, &server, REMOTE_PORT, Connected);

           tcp_recv(p_pcb, Receive);
           tcp_sent(p_pcb, Send);

           error = tcp_write(p_pcb, sendBuffer, sendBufferSize, TCP_WRITE_FLAG_COPY);   //This fails with error code -1 (out of memory).

           if (ERR_OK == error)
           {
               tcp_output(p_pcb);
           }

I tired increases the heap size in the project, but that didn't help. I can't even send 1 byte.

Can anyone tell me why I am getting an out of memory error?

over 9 years ago

0 Amit Ashara over 9 years ago

TI__Guru**** 244440 points

Hello Jo-Jo

Did you check increasing the Stack Size? Also is the tcp_write returning an error?

0 Jo-Jo Smith over 9 years ago in reply to Amit Ashara

Intellectual 390 points

Yes, tcp_write() is returning the error.

It looks like I kind of figured it out. If I put a delay of a couple seconds between connecting and writing, then it works as expected. Now I have a new questions.

Why do I need to delay after I connect, and is there some way to make it event driven, so I don't need an arbitrary delay?

0 Amit Ashara over 9 years ago in reply to Jo-Jo Smith

TI__Guru**** 244440 points

Hello Jo-Jo

I believe you would need to check that with the lwIP mailing list.

Arm-based microcontrollers

Arm-based microcontrollers forum

lwip Out of Memory Error