Add Timer and TimeKeeper to Display.

esp/cpp/07_lcd-panel/main/display.cpp

@@ -12,6 +12,9 @@
 // We must use a mutex to protect it.
 _lock_t Display::ScopedLock::lv_lock_;
 
+std::unordered_map<const char *, Display::Timer>
+    Display::TimeKeeper::managed_timers_;
+
 Display::Display(IPanelDevice &device) :
     panel_(device),
     lv_tick_timer_(nullptr)
@@ -152,15 +155,13 @@ void Display::lvgl_increase_tick(void *)
   }
 }
 
-void Display::register_lvgl_tick_timer() // NOLINT(*-convert-member-functions-to-static)
+void Display::register_lvgl_tick_timer()
 {
   ESP_LOGI(TAG, "Use esp_timer to increase LVGL tick");
   const esp_timer_create_args_t lvgl_tick_timer_args = {
       .callback = &Display::lvgl_increase_tick,
       .name = "lvgl_tick"
   };
-  esp_timer_handle_t lvgl_tick_timer = nullptr;
+  TimeKeeper::start_new_timer_periodic(lvgl_tick_timer_args,
-  ESP_ERROR_CHECK(esp_timer_create(&lvgl_tick_timer_args, &lvgl_tick_timer));
+                                       LVGL_TICK_PERIOD_MS * 1000);
-  ESP_ERROR_CHECK(esp_timer_start_periodic(lvgl_tick_timer,
-                                           LVGL_TICK_PERIOD_MS * 1000));
 }

esp/cpp/07_lcd-panel/main/display.h

@@ -5,6 +5,7 @@
 
 #include <unordered_map>
 #include <esp_timer.h>
+#include <memory>
 
 #include "panel.h"
 
@@ -13,6 +14,33 @@
 #define LVGL_TASK_PRIORITY     2
 
 class Display {
+  struct ScopedLock {
+    explicit ScopedLock() { _lock_acquire(&lv_lock_); }
+
+    ~ScopedLock() { _lock_release(&lv_lock_); }
+
+    // LVGL library is not thread-safe, this example calls LVGL APIs from tasks.
+    // We must use a mutex to protect it.
+    static _lock_t lv_lock_;
+  };
+
+  struct Timer {
+    explicit Timer(esp_timer_create_args_t args) : args_(args)
+    {
+      ESP_LOGI(TAG, "Creating esp_timer with name: %s", args.name);
+      ESP_ERROR_CHECK(esp_timer_create(&args, &esp_timer_));
+    }
+
+    ~Timer()
+    {
+      ESP_ERROR_CHECK(esp_timer_delete(esp_timer_));
+    }
+
+
+    [[maybe_unused]] esp_timer_create_args_t args_{};
+    esp_timer_handle_t esp_timer_ = nullptr;
+  };
+
 public:
   explicit Display(IPanelDevice &device);
 
@@ -43,6 +71,72 @@ public:
 
   [[noreturn]] static void lvgl_port_task(void *arg);
 
+  struct TimeKeeper {
+    using TimerHandle = Timer *;
+
+    // Timers should only be accessed using this method.
+    // For this reason managed_timers_ is private.
+    static TimerHandle get_handle(const char *name)
+    {
+      return &managed_timers_.at(name);
+    }
+
+    static TimerHandle create_timer(esp_timer_create_args_t args)
+    {
+      auto rt = managed_timers_.emplace(args.name, args);
+      if (!rt.second) {
+        ESP_LOGE(TAG, "Failed to insert timer into Display::managed_timers_");
+        return nullptr;
+      }
+      return &rt.first->second;
+    }
+
+    [[maybe_unused]] static void stop_timer(const char *name)
+    {
+      ESP_ERROR_CHECK(esp_timer_stop(get_handle(name)->esp_timer_));
+    }
+
+    [[maybe_unused]] static void delete_timer(const char *name)
+    {
+      managed_timers_.erase(name);
+    }
+
+    [[maybe_unused]] static void
+    start_new_timer_periodic(esp_timer_create_args_t args,
+                             uint64_t period)
+    {
+      start_timer_periodic(create_timer(args)->args_.name, period);
+    }
+
+    [[maybe_unused]] static void start_timer_periodic(const char *name,
+                                                      uint64_t period)
+    {
+      ESP_ERROR_CHECK(
+          esp_timer_start_periodic(get_handle(name)->esp_timer_, period));
+    }
+
+    [[maybe_unused]] static void
+    start_new_timer_once(esp_timer_create_args_t args,
+                         uint64_t timeout_us)
+    {
+      start_timer_once(create_timer(args)->args_.name, timeout_us);
+    }
+
+    [[maybe_unused]] static void start_timer_once(const char *name,
+                                                  uint64_t timeout_us)
+    {
+      ESP_ERROR_CHECK(
+          esp_timer_start_once(get_handle(name)->esp_timer_, timeout_us));
+    }
+
+    // TODO start_timer_once
+  private:
+
+    // Timers should only be accessed using the get_handle method.
+    // ~Timer() will delete the timer if called.
+    static std::unordered_map<const char *, Timer> managed_timers_;
+  };
+
 private:
   void register_lvgl_tick_timer();
 
@@ -60,16 +154,6 @@ private:
 
   // TODO: This could be a private struct
   esp_timer_handle_t lv_tick_timer_;
-
-  struct ScopedLock {
-    explicit ScopedLock() { _lock_acquire(&lv_lock_); }
-
-    ~ScopedLock() { _lock_release(&lv_lock_); }
-
-    // LVGL library is not thread-safe, this example calls LVGL APIs from tasks.
-    // We must use a mutex to protect it.
-    static _lock_t lv_lock_;
-  };
 };
 
 #endif // DISPLAY_H