Update Zephyr examples

examples/zephyr/http-client/src/main.c

@@ -11,6 +11,7 @@ static const char *s_post_data = NULL;     // POST data
 static const int64_t s_timeout_ms = 1500;  // Connect timeout in milliseconds
 struct mg_mgr s_mgr;
 static int s_connected = 0;
+static bool done = false;
 
 // Print HTTP response and signal that we're done
 static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
@@ -54,25 +55,23 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   }
 }
 
-// We have no valid system time(), and we need it for TLS. Implement it
-time_t time(time_t *tp) {
-  time_t t = s_boot_timestamp + k_uptime_get() / 1000;
+// example system time()-like function
+time_t ourtime(time_t *tp) {
+  time_t t = s_boot_timestamp + mg_millis() / 1000;
   if (tp != NULL) *tp = t;
   return t;
 }
 
-// SNTP callback. Modifies s_boot_timestamp, to make time() correct
+// SNTP callback. Modifies s_boot_timestamp, to make ourtime() correct
 static void sfn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_SNTP_TIME) {
     int64_t t = *(int64_t *) ev_data;
     MG_INFO(("Got SNTP time: %lld ms from epoch", t));
     s_boot_timestamp = (time_t) ((t - mg_millis()) / 1000);
 
-    // We need correct time in order to get HTTPs working, therefore,
-    // making https request from SMTP callback
     if (!s_connected) {
       MG_INFO(("Connecting to    : [%s]", s_url));
-      mg_http_connect(&s_mgr, s_url, fn, NULL);  // Create client connection
+      mg_http_connect(&s_mgr, s_url, fn, &done);  // Create client connection
       s_connected = 1;
     }
   } else if (ev == MG_EV_CLOSE) {
@@ -87,17 +86,33 @@ static void timer_fn(void *arg) {
   if (s_boot_timestamp < 9999) mg_sntp_request(s_sntp_conn);
 }
 
+// Zephyr: Define a semaphore and network management callback to be able to wait
+// until our IP address is ready. The main function will start and block on this
+// semaphore until this event handler releases it when the network is ready
+K_SEM_DEFINE(run, 0, 1);
+
+static void zeh(struct net_mgmt_event_callback *cb, uint32_t mgmt_event,
+                struct net_if *iface) {
+  if (mgmt_event == NET_EVENT_L4_CONNECTED) k_sem_give(&run);
+}
+
 int main(int argc, char *argv[]) {
+  // Zephyr: Register the network management callback and block on the semaphore
+  struct net_mgmt_event_callback ncb;
+  net_mgmt_init_event_callback(&ncb, zeh, NET_EVENT_L4_CONNECTED);
+  net_mgmt_add_event_callback(&ncb);
+  k_sem_take(&run, K_FOREVER);
+
   mg_log_set(MG_LL_DEBUG);
 
   mg_mgr_init(&s_mgr);
   mg_timer_add(&s_mgr, 5000, MG_TIMER_REPEAT | MG_TIMER_RUN_NOW, timer_fn,
                &s_mgr);
 
-  // Start infinite event loop
+  // Start event loop, exit when client is done
   MG_INFO(("Mongoose version : v%s", MG_VERSION));
 
-  for (;;) mg_mgr_poll(&s_mgr, 1000);
+  while (!done) mg_mgr_poll(&s_mgr, 1000);
   mg_mgr_free(&s_mgr);
 
   return 0;