Switched to queues for webserver

src/main.cpp

@@ -31,7 +31,6 @@
 
 Preferences prefs;
 
-extern WaterData water_data;
 extern DeviceTelemetry telemetry;
 extern NetworkData wifi_data;
 extern NetworkData ethernet_data;
@@ -101,16 +100,23 @@ void setup()
 
 
     LOG(ELOG_LEVEL_DEBUG, "Starting main tasks");
-    xTaskCreate(ethernet_task, "EthernetTask", 4096, NULL, 1, NULL);
-    xTaskCreate(wifi_task, "WiFiTask", 10000, NULL, 1, NULL);
-    xTaskCreate(read_sensor_task, "ReadSensorTask", 1024 * 4, NULL, 1, NULL);
-    xTaskCreate(collect_internal_telemetry_task, "InternalTelemetryTask", 2048, NULL, 1, NULL);
-    xTaskCreate(display_task, "DisplayTask", 10000, NULL, 1, NULL);
-    xTaskCreate(get_time_task, "GetTimeTask", 1024 * 4, NULL, 1, NULL);
+    
+    // Create a queue for water data communication between sensor and webserver tasks
+    QueueHandle_t webserverWaterDataQueue = xQueueCreate(10, sizeof(WaterData));
+    if (webserverWaterDataQueue == NULL) {
+        LOG(ELOG_LEVEL_ERROR, "Failed to create webserver water data queue");
+    } else {
+        xTaskCreate(ethernet_task, "EthernetTask", 4096, NULL, 1, NULL);
+        xTaskCreate(wifi_task, "WiFiTask", 10000, NULL, 1, NULL);
+        xTaskCreate(read_sensor_task, "ReadSensorTask", 1024 * 4, webserverWaterDataQueue, 1, NULL);
+        xTaskCreate(collect_internal_telemetry_task, "InternalTelemetryTask", 2048, NULL, 1, NULL);
+        xTaskCreate(display_task, "DisplayTask", 10000, NULL, 1, NULL);
+        xTaskCreate(get_time_task, "GetTimeTask", 1024 * 4, NULL, 1, NULL);
 
-    delay(5000);
-    xTaskCreate(check_update_task, "CheckUpdateTask", 1024 * 8, NULL, 1, NULL);
-    xTaskCreate(webserver_task, "WebServerTask", 1024 * 8, NULL, 1, NULL);
+        delay(5000);
+        xTaskCreate(check_update_task, "CheckUpdateTask", 1024 * 8, NULL, 1, NULL);
+        xTaskCreate(webserver_task, "WebServerTask", 1024 * 8, webserverWaterDataQueue, 1, NULL);
+    }
 
     LOG(ELOG_LEVEL_DEBUG, "Starting OTA handler");
     ArduinoOTA.begin();

src/networking/json_builder.cpp

@@ -1,7 +1,6 @@
 #include "json_builder.h"
 #include <Elog.h>
 
-extern WaterData water_data;
 extern DeviceTelemetry telemetry;
 extern NetworkData wifi_data;
 extern NetworkData ethernet_data;

src/networking/webserver.cpp

@@ -10,14 +10,17 @@
 #include "AsyncJson.h"
 #include <ArduinoJson.h>
 #include <SPIFFS.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/queue.h>
 
 #include "../global_data/global_data.h"
 #include "../tools/tools.h"
+#include "../tools/readers_writer_lock.h"
 #include "../global_data/defines.h"
 #include "json_builder.h"
 
 extern Preferences prefs;
-extern WaterData water_data;
 extern DeviceTelemetry telemetry;
 extern NetworkData wifi_data;
 extern NetworkData ethernet_data;
@@ -27,6 +30,15 @@ extern OTAStatus ota_status;
 AsyncWebSocket webSocket("/webSocket");
 AsyncWebServer server(80);
 
+// Local water data cache
+WaterData local_water_data;
+
+// Readers-writer lock for local_water_data
+ReadersWriterLock waterDataLock;
+
+// Queue to receive water data from the sensor task
+QueueHandle_t webserverWaterDataQueue;
+
 
 // ======================
 // Webserver Setup
@@ -84,19 +96,26 @@ void setup_api_endpoints(){
       request->send(200, "application/json", output); });
 
     server.on("/water_data", HTTP_GET, [](AsyncWebServerRequest* request) {
+      rwLockAcquireRead(&waterDataLock);
       String output;
-      serializeJson(build_water_data_json(water_data), output);
-      request->send(200, "application/json", output); });
+      serializeJson(build_water_data_json(local_water_data), output);
+      rwLockReleaseRead(&waterDataLock);
+      request->send(200, "application/json", output);
+    });
 
     server.on("/raw_percent", HTTP_GET, [](AsyncWebServerRequest* request) {
-      String output;
-      output = water_data.percentage;
-      request->send(200, "text/raw", output); });
+      rwLockAcquireRead(&waterDataLock);
+      String output = String(local_water_data.percentage);
+      rwLockReleaseRead(&waterDataLock);
+      request->send(200, "text/raw", output);
+    });
 
     server.on("/raw_level", HTTP_GET, [](AsyncWebServerRequest* request) {
-      String output;
-      output = water_data.level;
-      request->send(200, "text/raw", output); });
+      rwLockAcquireRead(&waterDataLock);
+      String output = String(local_water_data.level);
+      rwLockReleaseRead(&waterDataLock);
+      request->send(200, "text/raw", output);
+    });
   
     server.on("/telemetry", HTTP_GET, [](AsyncWebServerRequest* request) {
       String output;
@@ -215,18 +234,51 @@ void handle_update_sensor_settings(AsyncWebServerRequest* request) {
 /**
  * @brief Main task for the webserver.
  * 
- * Initializes all routes and starts the webserver.
+ * Initializes all routes, starts the webserver, and sets up local water data.
+ * Receives water data from the sensor task via a queue and updates local_water_data.
  * Runs indefinitely to keep the server active.
  * 
- * @param pvParameters Task parameters (unused).
+ * @param pvParameters Task parameters (expected to be a QueueHandle_t for the water data queue).
  */
 void webserver_task(void *pvParameters) {
+    // Extract the queue handle from the task parameters
+    webserverWaterDataQueue = (QueueHandle_t)pvParameters;
+    if (webserverWaterDataQueue == NULL) {
+        LOG(ELOG_LEVEL_ERROR, "Webserver water data queue is NULL");
+        vTaskDelete(NULL);
+        return;
+    }
+    
     LOG(ELOG_LEVEL_DEBUG, "Setting up routes");
     setup_routes();
     
+    // Initialize the readers-writer lock
+    if (!rwLockInit(&waterDataLock)) {
+        LOG(ELOG_LEVEL_ERROR, "Failed to initialize readers-writer lock");
+        vTaskDelete(NULL);
+        return;
+    }
+    
+    // Initialize local water data with static values
+    rwLockAcquireWrite(&waterDataLock);
+    local_water_data.level = 50.0f;
+    local_water_data.liters = 100.0f;
+    local_water_data.percentage = 50.0f;
+    rwLockReleaseWrite(&waterDataLock);
+    
     LOG(ELOG_LEVEL_DEBUG, "Starting webserver");
     server.begin();
+    
     while (1) {
-        vTaskDelay(portMAX_DELAY);
+        // Check if there is new water data in the queue
+        WaterData newWaterData;
+        if (xQueueReceive(webserverWaterDataQueue, &newWaterData, 0) == pdTRUE) {
+            // Update local_water_data with the new data from the queue
+            rwLockAcquireWrite(&waterDataLock);
+            local_water_data = newWaterData;
+            rwLockReleaseWrite(&waterDataLock);
+        }
+        
+        vTaskDelay(100 / portTICK_PERIOD_MS); // Small delay to reduce CPU usage
     }
 }

src/networking/webserver.h

@@ -1,6 +1,5 @@
 #ifndef ASYNC_WEBSERVER_H
 #define ASYNC_WEBSERVER_H
-#endif // ASYNC_WEBSERVER_H
 
 #include <ESPAsyncWebServer.h>
 #include <LittleFS.h>
@@ -13,3 +12,5 @@ void webserver_task(void *pvParameters);
 void handle_update_wifi_credentials(AsyncWebServerRequest* request);
 void handle_update_sensor_settings(AsyncWebServerRequest* request);
 
+#endif // ASYNC_WEBSERVER_H
+

src/sensor/sensor.cpp

@@ -3,6 +3,7 @@
 #include <Elog.h>
 #include "Wire.h"
 #include "../global_data/global_data.h"
+#include "../networking/webserver.h"
 
 
 #ifdef USE_INA226
@@ -47,6 +48,14 @@ void init_sensor(){
 
 void read_sensor_task(void* parameter)
 {
+    // Extract the queue handle from the task parameters
+    QueueHandle_t webserverWaterDataQueue = (QueueHandle_t)parameter;
+    if (webserverWaterDataQueue == NULL) {
+        LOG(ELOG_LEVEL_ERROR, "Webserver water data queue is NULL");
+        vTaskDelete(NULL);
+        return;
+    }
+    
     LOG(ELOG_LEVEL_DEBUG, "Starting read sensor tasks");
     while (true) {
         // Get Values from sensor
@@ -111,6 +120,11 @@ void read_sensor_task(void* parameter)
         water_data.liters = liters;
         water_data.percentage = percentage_rounded;
 
+        // Send the water data to the webserver task via the queue
+        if (xQueueSend(webserverWaterDataQueue, &water_data, 0) != pdTRUE) {
+            LOG(ELOG_LEVEL_ERROR, "Failed to send water data to webserver queue");
+        }
+
         delay(20000);
     }
 }

src/tools/readers_writer_lock.cpp

@@ -0,0 +1,70 @@
+#include "readers_writer_lock.h"
+#include <freertos/task.h>
+
+bool rwLockInit(ReadersWriterLock* rwLock) {
+    if (rwLock == NULL) {
+        return false;
+    }
+    
+    rwLock->mutex = xSemaphoreCreateMutex();
+    if (rwLock->mutex == NULL) {
+        return false;
+    }
+    
+    rwLock->readersCount = 0;
+    rwLock->writerActive = false;
+    
+    return true;
+}
+
+void rwLockAcquireRead(ReadersWriterLock* rwLock) {
+    if (rwLock == NULL) {
+        return;
+    }
+    
+    xSemaphoreTake(rwLock->mutex, portMAX_DELAY);
+    // Wait until no writer is active
+    while (rwLock->writerActive) {
+        xSemaphoreGive(rwLock->mutex);
+        vTaskDelay(10 / portTICK_PERIOD_MS); // Small delay to avoid busy-waiting
+        xSemaphoreTake(rwLock->mutex, portMAX_DELAY);
+    }
+    rwLock->readersCount++;
+    xSemaphoreGive(rwLock->mutex);
+}
+
+void rwLockReleaseRead(ReadersWriterLock* rwLock) {
+    if (rwLock == NULL) {
+        return;
+    }
+    
+    xSemaphoreTake(rwLock->mutex, portMAX_DELAY);
+    rwLock->readersCount--;
+    xSemaphoreGive(rwLock->mutex);
+}
+
+void rwLockAcquireWrite(ReadersWriterLock* rwLock) {
+    if (rwLock == NULL) {
+        return;
+    }
+    
+    xSemaphoreTake(rwLock->mutex, portMAX_DELAY);
+    // Set the writer active flag to block new readers
+    rwLock->writerActive = true;
+    // Wait until no readers are active
+    while (rwLock->readersCount > 0) {
+        xSemaphoreGive(rwLock->mutex);
+        vTaskDelay(10 / portTICK_PERIOD_MS); // Small delay to avoid busy-waiting
+        xSemaphoreTake(rwLock->mutex, portMAX_DELAY);
+    }
+    // Writer now has exclusive access
+}
+
+void rwLockReleaseWrite(ReadersWriterLock* rwLock) {
+    if (rwLock == NULL) {
+        return;
+    }
+    
+    rwLock->writerActive = false;
+    xSemaphoreGive(rwLock->mutex);
+}

src/tools/readers_writer_lock.h

@@ -0,0 +1,65 @@
+#ifndef READERS_WRITER_LOCK_H
+#define READERS_WRITER_LOCK_H
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+
+/**
+ * @brief Readers-Writer Lock structure.
+ * 
+ * This structure holds the state for a readers-writer lock,
+ * allowing multiple readers or a single writer to access a shared resource.
+ */
+typedef struct {
+    SemaphoreHandle_t mutex;   /**< Mutex to protect the lock state. */
+    int readersCount;         /**< Number of active readers. */
+    bool writerActive;        /**< Flag to indicate if a writer is active. */
+} ReadersWriterLock;
+
+/**
+ * @brief Initialize a readers-writer lock.
+ * 
+ * Initializes the mutex and sets the initial state of the lock.
+ * 
+ * @param rwLock Pointer to the ReadersWriterLock structure to initialize.
+ * @return true if initialization succeeded, false otherwise.
+ */
+bool rwLockInit(ReadersWriterLock* rwLock);
+
+/**
+ * @brief Acquire a read lock.
+ * 
+ * Blocks if a writer is active, otherwise allows multiple readers to access the data simultaneously.
+ * 
+ * @param rwLock Pointer to the ReadersWriterLock structure.
+ */
+void rwLockAcquireRead(ReadersWriterLock* rwLock);
+
+/**
+ * @brief Release a read lock.
+ * 
+ * Decrements the readers count.
+ * 
+ * @param rwLock Pointer to the ReadersWriterLock structure.
+ */
+void rwLockReleaseRead(ReadersWriterLock* rwLock);
+
+/**
+ * @brief Acquire a write lock.
+ * 
+ * Blocks until all readers have finished and sets the writer active flag.
+ * 
+ * @param rwLock Pointer to the ReadersWriterLock structure.
+ */
+void rwLockAcquireWrite(ReadersWriterLock* rwLock);
+
+/**
+ * @brief Release a write lock.
+ * 
+ * Clears the writer active flag and allows readers and writers.
+ * 
+ * @param rwLock Pointer to the ReadersWriterLock structure.
+ */
+void rwLockReleaseWrite(ReadersWriterLock* rwLock);
+
+#endif // READERS_WRITER_LOCK_H