Re: [lwip-users] TCP bandwidth limited by rate of ACKs

[Mason]

Simon wrote:

> Mason wrote:
> 
>> I tried using the Netconn API because I thought it didn't
>> force a memcpy (is that correct?), but I can't get it to work.
>
> Yes, that's correct. From your example, I guess you're running out of 
> netbufs: if netconn_recv returns success, it passes you a netbuf (the RX 
> data) and it's up to your application to free the buffer when you're 
> done with it.
>
>>    struct netconn *conn = netconn_new( NETCONN_TCP );
>>    netconn_bind(conn, IP_ADDR_ANY, 44044);
>>    netconn_listen(conn);
>>    while ( 1 )
>>    {
>>      struct netconn *foo;
>>      netconn_accept(conn,&foo);
>>      while ( 1 )
>>      {
>>        struct netbuf *buf;
>>        err = netconn_recv(foo,&buf);
>>        if (err) { printf("recv=%d\n", err); break; }
> 
> --> Add netbuf_free(buf); here
> 
>>      }
>>      netconn_delete(foo);
>>    }

I must be missing something, because it looks like there's a small
memory leak: netconn_recv allocates memory for a struct netbuf

  buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);

but netbuf_free does not free this memory

void netbuf_free(struct netbuf *buf)
{
  if (buf->p != NULL) { pbuf_free(buf->p); }
  buf->p = buf->ptr = NULL;
}

Am I supposed to call netbuf_delete instead?

http://lwip.wikia.com/wiki/Netbuf_delete

void netbuf_delete(struct netbuf *buf)
{
  if (buf != NULL) {
    if (buf->p != NULL) {
      pbuf_free(buf->p);
      buf->p = buf->ptr = NULL;
    }
    memp_free(MEMP_NETBUF, buf);
  }
}

-- 
Regards.