[lwip-users] lwIP PPP for single threaded context

[Wagner Hans-Jörg]

Hi everybody

I know I am number 748 posting this question but looking at postings having the similar question as me, I didn't find any programming examples.

I plan to take the lwIP with PPP to a single threaded context, because our braindead Operating System OSE has such specific mailbox handling and process creation, that I seems to me it would be the best to use the tcp callback api.

However the pppOpen requires creating a thread. In my opinion even this could be managed in a workaround (has somebody an idea how to do it and how the while loop in the pppMain could be broken up?).

The key question is: What should I do with the callback functions in ppp.c if there is no tcpip thread pending on a mailbox? Why is there the comment in ppp.c:

/* these callbacks are necessary because lcp_* functions
   must be called in the same context as pppInput(),
   namely the tcpip_thread(), essentially because
   they manipulate timeouts which are thread-private
*/
static void
pppStartCB(void *arg)
{

static void
pppStopCB(void *arg)
{

Could there something go wrong if I just call the client callback functions directly instead of being synchronized with the tcpip thread through a mailbox (I wont have a tcpip thread in my context)? In a single threaded context I am in the same thread context as the tcpip thread afaik.

Thus something in the ppp.c like:

static void pppInProc(int pd, u_char *s, int l)
{
   //some stuff

   //instead of registering pppInput as a callback
   //and sending a message to the tcpip thread
   //(that doesnt exist in my context) .....

      /* Dispatch the packet thereby consuming it. */
      if(tcpip_callback(pppInput, pc->inHead) != ERR_OK) {

   //.... can I just call the callback function directly?
   //like
     
      pppInput(pc->inHead);


TIA
George