Diff: mqtt.h

Revision:

2:f10d6fecb345

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mqtt.h	Fri Dec 06 15:47:37 2019 +0000
@@ -0,0 +1,111 @@
+#ifndef _MQTT_H_
+#define _MQTT_H_
+
+#include "mbed.h"
+#include "MQTTNetwork.h"
+#include "MQTTClient.h"
+#include "MQTTmbed.h"
+#include <assert.h>
+
+#define MAX_CARS_ON_ROAD 5
+
+enum drive_state_t{
+ NORMAL_STATE = 0,
+ STOPPED_STATE,
+ CROSSING_STATE
+};
+
+typedef struct position_msg{
+    int position;
+    int speed;
+    int car_id;
+    int road_id; 
+    int counter; // for debugging and ensuring everyone is synchronized
+    drive_state_t state; // for debugging
+}position_msg_t;
+
+
+typedef struct control_msg{
+    int speed;
+    int car_id;
+    int road_id;
+    int counter; // for debugging synchronization
+}control_msg_t;
+
+
+class mqtt{
+
+private:
+    // static functions for control message callbacks
+    static void control_message_arrived(MQTT::MessageData& md);
+    
+    // functions for creatin of mqtt and wifi bring up
+    WiFiInterface* setup_wifi();
+    int send_position_msg(position_msg_t* msg);
+    void manage_network();
+    void bringup_network();
+    
+    // data structures needed for creation of network
+    MQTT::Client<MQTTNetwork, Countdown>* client;
+    MQTT::Client<MQTTNetwork, Countdown>* setup_mqtt(MQTTNetwork& network); 
+    MQTTNetwork* new_network;
+    
+    // thread that will manage the mqtt network status
+    Thread* thread;
+    
+    // queue for sending position msessages
+    Queue<position_msg_t, 16> position_queue;
+    
+    // queue for control message passsing between mqtt and car threads
+    Queue<control_msg_t, 1> control_queue[MAX_CARS_ON_ROAD];
+
+    
+public:
+    // singleton instance for managing network
+    // we can only have one network so this should prohibit accidental
+    // creations of multiple objects
+    static mqtt* mqtt_singleton;
+    
+    //
+    int mqtt_id;
+    
+    // empty constructor
+    mqtt();
+    
+    // setup and tear down API's
+    void setup_network();
+    int shutdown_network();
+
+    
+    static mqtt *instance()
+    {
+        if (!mqtt_singleton)
+          mqtt_singleton = new mqtt;
+        return mqtt_singleton;
+    }
+    
+    // adding to a queue to be sent on mqtt network
+    inline void add_to_position_queue(position_msg_t* msg)
+    {
+        position_queue.put(msg);
+    }
+    
+    // adding to a queue to be sent on mqtt network
+    inline void add_to_control_queue(int car_id,control_msg_t* msg)
+    {
+        control_queue[car_id].put(msg);
+    }
+    
+    // adding to a queue to be sent on mqtt network
+    inline control_msg_t* get_control_msg(int car_id)
+    {
+        osEvent evt = control_queue[car_id].get();
+        assert(evt.status == osEventMessage);
+        control_msg_t *message = (control_msg_t*)evt.value.p;
+        return message;
+    }
+    
+};
+
+
+#endif
\ No newline at end of file