lwip stack question using tcp/udp_new(), especially, about LWIP_TCPIP_CORE_LOCKING

[Seongyon_Jeong]

Hi,   and.. sorry .   exactly say,   It  is  lwip stack question in SDK(2.13 EVK-MIMXRT1020),   but . Please  help ..

I am developting  project by using   SDK with RT1020, so ,  really .. I do not know  what I have to do..  

. I will make  4ea tcp/udp task  with  8 connections, each port. 2connection.

Question1.

I can not understand  differences between  [udp_new -> udp bind -> udp_recv-> udp_remove ] and 

[sock(for udp) -> bind -> recvfrom -> close.]  process. .  tcpip case. same.  tcp_new ~ tcp_bind~~~~ 

what is the difference ??    Purpose of use  (TCP/UDP)_new() ??

Question 2.

From SDK example, (evkmimxrt1020_lwip_ipv4_ipv6_echo_freertos), 

#define LWIP_TCPIP_CORE_LOCKING 1    in lwipopts.h so.  After adding new task  on stack_init.

static void stack_init(void *arg)
{
~~~
     shell_task_init(NULL, 0);
      xTaskCreate( Start_xxx, ( const char * const )"xxxLauncher",
                 configMINIMAL_STACK_SIZE + 4096 , NULL, INIT_THREAD_PRIO, NULL );

    vTaskDelete(NULL);
}

static void Start_xxx(void *arg) {
    ~~~
    udp_new();
    udp_bind();
    while(~~) {
    udp_recv();
    ~~~ }
}

this code  is stuck,   with message  "function called without core lock"

so,  Every calling of  udp_xxx()  function group,  I need  to attach locking like below

LOCK_TCPIP_CORE();
udp_new();
UNLOCK_TCPIP_CORE();

LOCK_TCPIP_CORE();
udp_bind();
UNLOCK_TCPIP_CORE();

LOCK_TCPIP_CORE();
udp_recv();
UNLOCK_TCPIP_CORE();

But It is so uncomfortable...       Why locking  sentence  is not inside udp_xxx();

and  From googling  with keyword  "udp_new",   nealy, I cannot find   this uncomfortable code  including   lock/unlock  before-after  udp_xxxx()

So,  Is there  any good example (from SDK, or not)   using  tcp/udp_xxxx() func.  ??

And  Really , Do I need to add  lock/unlock  code  back and forth of every tcp/udp_xxxx() func?

or  How about  this ?  In lwipopts.h

/* ---------- Core locking ---------- */

#define LWIP_TCPIP_CORE_LOCKING 0

void sys_lock_tcpip_core(void);
#define LOCK_TCPIP_CORE() //sys_lock_tcpip_core()

void sys_unlock_tcpip_core(void);
#define UNLOCK_TCPIP_CORE() //sys_unlock_tcpip_core()

void sys_check_core_locking(void);
#define LWIP_ASSERT_CORE_LOCKED() //sys_check_core_locking()

void sys_mark_tcpip_thread(void);
#define LWIP_MARK_TCPIP_THREAD() //sys_mark_tcpip_thread()

[Seongyon_Jeong]

attach link,    

https://community.nxp.com/t5/MCUXpresso-SDK-Knowledge-Base/Developing-LwIP-Application-with-Sequenti...

https://community.nxp.com/t5/MCUXpresso-SDK-Knowledge-Base/Developing-LwIP-Applications-with-Raw-API...

[Seongyon_Jeong]

thanks.  In the middle of finding  netconn API,  I found page about  sequential API, Raw API,  and  Also,  SDK Example already includs raw, sequential examples. \lwip\contrib\apps\tcpecho & tcpecho_raw... etc   from example - evkmimxrt1020_lwip_ipv4_ipv6_echo_freertos. 

anyway ,  Before your answer,

In my project,...   in spite of using Locking macro, Program  halt Occured.   It would be from too many packet receive,  just my opinion, so

In  lwipopts.h, opt.h, after  enlarging kind of buffer size option, task stack Size, ...  But.  also  halt is occured agin.  during  receive-packets       

so I used  DisableIRQ(ENET_IRQn)  just during   process_received_packet function .   like below...

{

  LOCK_TCPIP_CORE() 

   udp_recv( callback_fn )

  UNLOCK~

   while(1) {   DisableIRQ(ENET_IRQn);   receiveProcess( xQueueReceive );  EnableIRQ(ENET_IRQn);  }

}

callbakc_fn  {   xQueueCreate, and  push packet }

It`s like sequential.API..  anyway thanks,  I will consider  netconn API.

[Omar_Anguiano · Accepted solution]

Q1. The main difference is the Transport protocol used, I suggest you use netconn_xxx functions as you can specify the parameter for transport protocol.

Q2. Unfortunately, we don’t have a specific example where tcp/udp_xxx() is used.

Best regards,
Omar