chore: Initial multi-core compatibility (#2294)

src/activities/ActivityManager.cpp

@@ -19,12 +19,15 @@
 #include "settings/SettingsActivity.h"
 #include "util/FullScreenMessageActivity.h"
 
+static portMUX_TYPE activityManagerSpinlock = portMUX_INITIALIZER_UNLOCKED;
+
 void ActivityManager::begin() {
-  xTaskCreate(&renderTaskTrampoline, "ActivityManagerRender",
-              8192,              // Stack size
-              this,              // Parameters
-              1,                 // Priority
-              &renderTaskHandle  // Task handle
+  xTaskCreatePinnedToCore(&renderTaskTrampoline, "ActivityManagerRender",
+                          8192,               // Stack size
+                          this,               // Parameters
+                          1,                  // Priority
+                          &renderTaskHandle,  // Task handle
+                          0                   // Pin to core 0 (PRO_CPU)
   );
   assert(renderTaskHandle != nullptr && "Failed to create render task");
 }
@@ -46,10 +49,10 @@ void ActivityManager::renderTaskLoop() {
     }
     // Notify any task blocked in requestUpdateAndWait() that the render is done.
     TaskHandle_t waiter = nullptr;
-    taskENTER_CRITICAL(nullptr);
+    taskENTER_CRITICAL(&activityManagerSpinlock);
     waiter = waitingTaskHandle;
     waitingTaskHandle = nullptr;
-    taskEXIT_CRITICAL(nullptr);
+    taskEXIT_CRITICAL(&activityManagerSpinlock);
     if (waiter) {
       xTaskNotify(waiter, 1, eIncrement);
     }
@@ -137,8 +140,7 @@ void ActivityManager::loop() {
     }
   }
 
-  if (requestedUpdate) {
-    requestedUpdate = false;
+  if (requestedUpdate.exchange(false)) {
     // Using direct notification to signal the render task to update
     // Increment counter so multiple rapid calls won't be lost
     if (renderTaskHandle) {
@@ -280,7 +282,7 @@ void ActivityManager::requestUpdateAndWait() {
   }
 
   // Atomic section to perform checks
-  taskENTER_CRITICAL(nullptr);
+  taskENTER_CRITICAL(&activityManagerSpinlock);
   auto currTaskHandler = xTaskGetCurrentTaskHandle();
   auto mutexHolder = xSemaphoreGetMutexHolder(renderingMutex);
   bool isRenderTask = (currTaskHandler == renderTaskHandle);
@@ -289,7 +291,7 @@ void ActivityManager::requestUpdateAndWait() {
   if (!alreadyWaiting && !isRenderTask && !holdingRenderLock) {
     waitingTaskHandle = currTaskHandler;
   }
-  taskEXIT_CRITICAL(nullptr);
+  taskEXIT_CRITICAL(&activityManagerSpinlock);
 
   // Render task cannot call requestUpdateAndWait() or it will cause a deadlock
   assert(!isRenderTask && "Render task cannot call requestUpdateAndWait()");