feat(modules): pause background threads when display is asleep

Currently, modules polling hardware nodes continuously wake up kernel drivers even when the monitor is asleep (e.g., DPMS off), flooding dmesg.

- Adds 'disable-on-sleep' config flag
- Hooks GTK window map/unmap signals to track DPMS state
- Propagates suspend/resume calls to AModule worker threads

include/AModule.hpp

@@ -25,6 +25,10 @@ class AModule : public IModule {
 
   bool expandEnabled() const;
 
+  virtual void suspend() {};
+  virtual void resume() {};
+  bool shouldSuspend() const { return disable_on_sleep_; }
+
  protected:
   // Don't need to make an object directly
   // Derived classes are able to use it
@@ -48,6 +52,8 @@ class AModule : public IModule {
   virtual bool handleMouseLeave(GdkEventCrossing* const& ev);
   virtual bool handleScroll(GdkEventScroll*);
   virtual bool handleRelease(GdkEventButton* const& ev);
+
+  bool disable_on_sleep_{false};
   GObject* menu_ = nullptr;
 
  private:

include/bar.hpp

@@ -75,6 +75,8 @@ class Bar : public sigc::trackable {
   util::KillSignalAction getOnSigusr1Action();
   util::KillSignalAction getOnSigusr2Action();
 
+  void toggleSuspend(bool suspend);
+
   struct waybar_output* output;
   Json::Value config;
   struct wl_surface* surface;

include/modules/temperature.hpp

@@ -14,6 +14,8 @@ class Temperature : public ALabel {
   Temperature(const std::string&, const Json::Value&);
   virtual ~Temperature() = default;
   auto update() -> void override;
+  void suspend() override;
+  void resume() override;
 
  private:
   float getTemperature();

include/util/sleeper_thread.hpp

@@ -79,6 +79,12 @@ class SleeperThread {
   auto sleep_for(std::chrono::system_clock::duration dur) {
     std::unique_lock lk(mutex_);
     CancellationGuard cancel_lock;
+
+    condvar_.wait(lk, [this] {
+      return !is_paused_ || signal_.load(std::memory_order_relaxed) ||
+             !do_run_.load(std::memory_order_relaxed);
+    });
+
     constexpr auto max_time_point = std::chrono::steady_clock::time_point::max();
     auto wait_end = max_time_point;
     auto now = std::chrono::steady_clock::now();
@@ -95,6 +101,12 @@ class SleeperThread {
           time_point) {
     std::unique_lock lk(mutex_);
     CancellationGuard cancel_lock;
+
+    condvar_.wait(lk, [this] {
+      return !is_paused_ || signal_.load(std::memory_order_relaxed) ||
+             !do_run_.load(std::memory_order_relaxed);
+    });
+
     return condvar_.wait_until(lk, time_point, [this] {
       return signal_.load(std::memory_order_relaxed) || !do_run_.load(std::memory_order_relaxed);
     });
@@ -122,6 +134,17 @@ class SleeperThread {
     }
   }
 
+  void pause() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    is_paused_ = true;
+  }
+
+  void resume() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    is_paused_ = false;
+    condvar_.notify_all();
+  }
+
   ~SleeperThread() {
     connection_.disconnect();
     stop();
@@ -137,6 +160,7 @@ class SleeperThread {
   std::atomic<bool> do_run_ = true;
   std::atomic<bool> signal_ = false;
   sigc::connection connection_;
+  bool is_paused_{false};
 };
 
 }  // namespace waybar::util