Re: [lwip-users] How to close tcp_thread

[Yoav Nissim]

Hi tes_wzm (...?)
I am using lwIP 3.0 at the moment and had to shut it down as well.
My solution may not be perfect, but at least it works without any thread killing...

1. I added a TCPIP_MSG_TERMINATE tcpip_msg_type to the enumeration

2. I added a case to the tcpip_thread switch:

    while(1) {    /* Main Loop */
    ...
    ...
    case TCPIP_MSG_TERMINATE:
      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: Terminating\n"));
      sys_sem_signal(*(msg->sem));
      return;
    }

3. I added the tcpip_terminate() function to tcpip.c

void
tcpip_terminate(void)
{
  struct tcpip_msg msg;
  sys_sem_t sem;

  /* If there is no tcpip mailbox, leave */
  if (mbox == SYS_MBOX_NULL)
      return;

  /* Create semaphore for message */
  sem = sys_sem_new(0);
  /* TODO: how should we handle failure here? */
  LWIP_ASSERT("tcpip_terminate: failed to create semaphore\n",
      sem != SYS_SEM_NULL);

  /* TODO: do we need to stop the timers? if so, how? */

  /* Tell tcpip thread to exit, and wait */
  msg.sem = &sem;
  msg.type = TCPIP_MSG_TERMINATE;
  sys_mbox_post(mbox, &msg);
  sys_arch_sem_wait(sem, 0);

  /* clean up tcpip thread resources */
  sys_mbox_free(mbox);
  sys_sem_free(sem);
  mbox = SYS_MBOX_NULL;

  /* clean up all initialized lwip components */
  lwip_cleanup();
}


4. Before calling tcpip_terminate(), you had better make sure you clean up all PPP sessions, interfaces, and anything else you've initialized via the tcpip based APIs.

5. The lwip_cleanup() at the end of the function is not a part of lwIP. I've added it in init.c as a reciprocal for lwip_init(). It basically needs to clean up any resources that lwip_init() allocates, but I did not get to do that part yet (nor even check if its necessary).


HTH,
Yoav.





On 29/03/10 10:36 AM, tes_wzm wrote:

I use lwip+ppp to send data to my tcp server. When sth occured, I want to close tcp thread. How can I do it? If I kill this thread through OS, it will leak some memory which use to create mailbox and sem. Is't some routes to release this memory?
View this message in context: How to close tcp_thread
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-- 
Yoav Nissim
Software Engineer, Software Tools Division
Jungo Software Technologies
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