[lwip-devel] Semaphore assertion in tcpip_init_done

[Kieran Mansley]

I think there might be a problem with the way some of the unix port apps 
are using semaphores or tcpip_init() after the recent changes to the 
sys_sem API.

The apps do things like this:

  sys_sem_t sem;

  netif_init();

  if(sys_sem_new(&sem, 0) != ERR_OK) {
    LWIP_ASSERT("Failed to create semaphore", 0);
  }
  tcpip_init(tcpip_init_done, &sem);
  sys_sem_wait(&sem);

But when run they are hitting an assertion in their tcpip_init_done 
function where it tries to signal the semaphore.  That function is doing 
this:

tcpip_init_done(void *arg)
{
  sys_sem_t *sem;
  sem = arg;

  init_netifs();

  sys_sem_signal(*sem);
}

sys_sem_signal (again in the unix port) has the assertion:

sys_sem_signal(struct sys_sem **s)
{
  struct sys_sem *sem;
  LWIP_ASSERT("invalid sem", (s != NULL) && (*s != NULL));
  

As you can see, sys_sem_signal takes a "struct sys_sem **" but it is 
being called with a "sys_sem_t".  I'm not sure after the recent changes 
which of these bits is in error.  I wonder if anyone can help me work 
out which is wrong?  I'm happy to update the port as necessary.

Thanks

Kieran