Add mutex to global race data.

src/main.cpp

@@ -5,6 +5,7 @@
 #include "F1_api.h"
 #include "FreeRTOS.h"
 #include "task.h"
+#include <semphr.h>
 
 #include "config.h"
 
@@ -21,7 +22,9 @@ static constexpr UWORD COUNTER_HEIGHT = 24;
 static constexpr UWORD COUNTER_Y = 20;
 static UBYTE counterBuffer[(COUNTER_WIDTH / 8) * COUNTER_HEIGHT];
 static int counter = 0;
-race_info next_race;
+
+race_info_t race_data;
+SemaphoreHandle_t dataMutex;
 
 void wifi_connect() {
     WiFi.setHostname(DEVICE_HOSTNAME);
@@ -78,6 +81,7 @@ bool readLocalTime(struct tm* result) {
 }
 
 void display_loop(void *pvParameters) {
+    static race_info_t local_data;
     while (true) {
         static unsigned long lastRefresh = 0;
         static char counterStr[32];
@@ -91,12 +95,22 @@ void display_loop(void *pvParameters) {
 
         counter++;
 
-        if (next_race.session_key == 0) {
+        if (xSemaphoreTake(dataMutex, MUTEX_TIMEOUT_TICKS)) {
+            local_data = race_data;
+            xSemaphoreGive(dataMutex);
+            //Display will continue to use old data
+        } else {
+            Serial.print("");
+            Serial.println("Failed to acquire mutex in display thread!");
+        }
+
+
+        if (race_data.session_key == 0) {
             snprintf(counterStr, sizeof(counterStr), "Counter: %d", counter);
             Serial.print("");
             Serial.println(counterStr);
         } else {
-            snprintf(counterStr, sizeof(counterStr), "%s", next_race.circuit_short_name);
+            snprintf(counterStr, sizeof(counterStr), "%s", race_data.circuit_short_name);
         }
 
         Paint_Clear(WHITE);
@@ -116,6 +130,12 @@ void display_loop(void *pvParameters) {
 void setup() {
     Serial.begin(115200);
 
+    dataMutex = xSemaphoreCreateMutex();
+    if (dataMutex == NULL) {
+        Serial.println("Failed to create mutex!");
+        while(1);
+    }
+
     if (DEV_Module_Init() != 0) {
         Serial.println("Failed to initialize display module.");
         return;