Time

mg_millis()

uint64_t mg_millis(void);

Return current uptime in milliseconds.

Parameters: None

Return value: Current uptime

Usage example:

uint64_t uptime = mg_millis();

mg_now()

uint64_t mg_now(void);

Return current time in milliseconds, requires an SNTP server connection (see mg_sntp_connect())

Parameters: None

Return value: If an SNTP server connection has been configured, returns current time. Otherwise, returns current uptime just like mg_millis()

Usage example:

mg_sntp_connect(mgr&, NULL /* connect to time.google.com */, NULL, NULL);
...
uint64_t curtime = mg_now();

mg_timer_expired()

bool mg_timer_expired(uint64_t *t, uint64_t period, uint64_t now);

Parameters:

• t - Pointer to a the timer value
• period - timer interval
• now - current time

Return true if a given timer t has expired: now >= *t, false otherwise. If the timer has expired, the t is advanced by the period.

Usage example:

uint64_t timer = 0, period = 500;  // Milliseconds
for (;;) {
  if (mg_timer_expired(&timer, period, mg_now())) {
    MG_INFO(("Hi!"));   // Print a message every 1/2 second
  }
  mg_mgr_poll(&mgr, 10);
}

mg_sntp_connect()

struct mg_connection *mg_sntp_connect(struct mg_mgr *mgr, const char *url,
                                      mg_event_handler_t fn, void *fn_data)

Connect to an SNTP server.

Parameters:

• mgr - Event manager to use
• url - Specifies remote URL, time.google.com if NULL.
• fn - A user event handler function, use NULL if you don't need one
• fn_data - an arbitrary pointer, which will be stored in the connection structure as c->fn_data, so the event handler can use it when called.

Return value: created connection, or NULL on error. Possible errors are: not enough memory, a NULL URL, or, in the case of our built-in TCP/IP stack, the network not being ready.

Simplest usage example: see mg_now()

Full usage example:

static void sntp_cb(struct mg_connection *c, int ev, void *ev_data) {
  if (ev == MG_EV_SNTP_TIME) {
    // Time received, the internal protocol handler updates what mg_now() returns
    uint64_t curtime = mg_now();
    // otherwise, you can process the server returned data yourself
    uint64_t epoch_millis = *(uint64_t *) ev_data;
  }
}
...
mg_sntp_connect(mgr&, NULL /* connect to time.google.com */, sntp_cb, NULL);

mg_sntp_request()

void mg_sntp_request(struct mg_connection *c)

Send time request to SNTP server

Parameters:

• c - Connection to use

Return value: None

Usage example:

mg_sntp_request(c);