diff --git a/examples/mqtt-client/main.c b/examples/mqtt-client/main.c index 2c5c9ff8..294a8ce7 100644 --- a/examples/mqtt-client/main.c +++ b/examples/mqtt-client/main.c @@ -3,9 +3,10 @@ // // Example MQTT client. It performs the following steps: // 1. Connects to the MQTT server specified by `s_url` variable -// 2. When connected, subscribes to the topic `s_topic` -// 3. Publishes message `hello` to the `s_topic` -// 4. Receives that message back from the subscribed topic and exits +// 2. When connected, subscribes to the topic `s_sub_topic` +// 3. Publishes message `hello` to the `s_pub_topic` +// 4. Receives that message back from the subscribed topic and closes +// 5. Timer-based reconnection logic revives the connection when it is down // // To enable SSL/TLS for this client, build it like this: // make MBEDTLS_DIR=/path/to/your/mbedtls/installation @@ -13,11 +14,14 @@ #include "mongoose.h" static const char *s_url = "mqtt://broker.hivemq.com:1883"; -static const char *s_topic = "mg/mq-clnt-test"; +static const char *s_sub_topic = "mg/+/test"; +static const char *s_pub_topic = "mg/clnt/test"; static int s_qos = 1; +static struct mg_connection *s_conn; static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) { if (ev == MG_EV_OPEN) { + LOG(LL_INFO, ("CREATED")); // c->is_hexdumping = 1; } else if (ev == MG_EV_ERROR) { // On error, log error message @@ -30,37 +34,47 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) { } } else if (ev == MG_EV_MQTT_OPEN) { // MQTT connect is successful - struct mg_str topic = mg_str(s_topic), data = mg_str("hello"); + struct mg_str subt = mg_str(s_sub_topic); + struct mg_str pubt = mg_str(s_pub_topic), data = mg_str("hello"); LOG(LL_INFO, ("CONNECTED to %s", s_url)); - mg_mqtt_sub(c, &topic, s_qos); - LOG(LL_INFO, ("SUBSCRIBED to %.*s", (int) topic.len, topic.ptr)); - mg_mqtt_pub(c, &topic, &data, s_qos, false); + mg_mqtt_sub(c, &subt, s_qos); + LOG(LL_INFO, ("SUBSCRIBED to %.*s", (int) subt.len, subt.ptr)); + + mg_mqtt_pub(c, &pubt, &data, s_qos, false); LOG(LL_INFO, ("PUBSLISHED %.*s -> %.*s", (int) data.len, data.ptr, - (int) topic.len, topic.ptr)); + (int) pubt.len, pubt.ptr)); } else if (ev == MG_EV_MQTT_MSG) { // When we get echo response, print it struct mg_mqtt_message *mm = (struct mg_mqtt_message *) ev_data; LOG(LL_INFO, ("RECEIVED %.*s <- %.*s", (int) mm->data.len, mm->data.ptr, (int) mm->topic.len, mm->topic.ptr)); + c->is_closing = 1; + } else if (ev == MG_EV_CLOSE) { + LOG(LL_INFO, ("CLOSED")); + s_conn = NULL; // Mark that we're closed } + (void) fn_data; +} - if (ev == MG_EV_ERROR || ev == MG_EV_CLOSE || ev == MG_EV_MQTT_MSG) { - LOG(LL_INFO, ("Got event %d, stopping...", ev)); - *(bool *) fn_data = true; // Signal that we're done - } +// Timer function - recreate client connection if it is closed +static void timer_fn(void *arg) { + struct mg_mgr *mgr = (struct mg_mgr *) arg; + struct mg_mqtt_opts opts = {.qos = s_qos, + .will_topic = mg_str(s_pub_topic), + .will_message = mg_str("goodbye")}; + if (s_conn == NULL) s_conn = mg_mqtt_connect(mgr, s_url, &opts, fn, NULL); } int main(void) { struct mg_mgr mgr; - struct mg_mqtt_opts opts = {.qos = s_qos, - .will_topic = mg_str(s_topic), - .will_message = mg_str("goodbye")}; - bool done = false; // Event handler sets this to true + struct mg_timer timer; + int topts = MG_TIMER_REPEAT | MG_TIMER_RUN_NOW; - mg_mgr_init(&mgr); // Initialise event manager - mg_mqtt_connect(&mgr, s_url, &opts, fn, &done); // Create client connection - while (done == false) mg_mgr_poll(&mgr, 1000); // Loop until done - mg_mgr_free(&mgr); // Finished, cleanup + mg_mgr_init(&mgr); // Init event manager + mg_timer_init(&timer, 3000, topts, timer_fn, &mgr); // Init timer + for (;;) mg_mgr_poll(&mgr, 1000); // Event loop, 1s timeout + mg_mgr_free(&mgr); // Finished, cleanup + mg_timer_free(&timer); // Free timer resources return 0; }