refactor(cava): fix thread-safety, resource leaks, and style violations

Comprehensive refactor of the cava module backend and frontends.

Style & naming
- Rename Cava -> CavaRaw; snake_case methods -> lowerCamelCase
- Replace NULL with nullptr; replace C-style casts with static_cast
- Add explicit standard-library includes (<memory>, <string>, <chrono>)
- Fix missing trailing underscores on member variables

Architecture
- Remove Gtk::GLArea multiple inheritance in CavaGLSL (composition)
- Return std::unique_ptr from factory; add doAction() to GLSL variant
- Encapsulate thread timing arithmetic in AdaptiveDelay struct

Thread safety & correctness
- Replace raw sigc::signal with SafeSignal for cross-thread marshalling
- Fix data race between loadConfig() and out_thread_ (recursive_mutex)
- Fix audio_raw shallow-copy use-after-free via deep-copy AudioRaw payload
- Make loadConfig() exception-safe with CavaConfigGuard RAII
- Fix blocking read_thread_ race on shutdown (condition_variable + timeout join)
- Fix isSilent() data race (acquire pthread mutex)
- Eliminate doUpdate() recursion (iteration instead)
- Guard audio_raw_clean() against uninitialized state
- Fix format-icons underflow and cava_config buffer overflow
- Store config by value to prevent dangling references on reload
- Cache frontend config and refresh on runtime changes
- Fix signed-char icon lookup bug on x86
- Prevent Json::Value mutation bloat via const-ref lookups
- Broaden exception catches in worker threads (std::exception)

Resource management & GL robustness
- Fix OpenGL resource leaks (persist VBO/IBO/VAO; explicit destructor cleanup)
- Fix shader error handling crashes (valid infoLog allocation)
- Cache uniform locations instead of querying per frame
- Fix gradient color uninitialized stack memory (zero-init + clamped count)
- Fix shader time uniform integer division bug (float arithmetic)
- Add explicit VAO bind in onRender()
- Handle runtime surface config changes independently of shader changes
- Clamp negative gradient_count before GL upload

Follow-up
- Singleton API split (inst() + configure()) intentionally deferred to a
  dedicated PR because it changes the public constructor contract.

include/modules/cava/cavaGLSL.hpp

@@ -1,36 +1,64 @@
 #pragma once
 
 #include <epoxy/gl.h>
+#include <gtkmm/glarea.h>
+#include <map>
+#include <string>
+#include <array>
+
+#include <sigc++/connection.h>
 
 #include "AModule.hpp"
 #include "cava_backend.hpp"
 
 namespace waybar::modules::cava {
 
-class CavaGLSL final : public AModule, public Gtk::GLArea {
+class CavaGLSL final : public AModule {
  public:
   CavaGLSL(const std::string&, const Json::Value&);
-  ~CavaGLSL() = default;
+  ~CavaGLSL();
+  auto doAction(const std::string& name) -> void override;
 
  private:
+  using Action = void (CavaGLSL::*)();
+
+  Gtk::GLArea gl_area_;
   std::shared_ptr<CavaBackend> backend_;
-  struct ::cava::config_params prm_;
-  int frame_counter{0};
+  // Cached config params (deep-copied strings to avoid dangling char* on backend reload)
+  int sdl_width_{0};
+  int sdl_height_{0};
+  int bar_width_{0};
+  int bar_spacing_{0};
+  int gradient_count_{0};
+  std::string vertex_shader_;
+  std::string fragment_shader_;
+  std::string bcolor_;
+  std::string color_;
+  std::array<std::string, 8> gradient_colors_;
+  int frame_counter_{0};
   bool silence_{false};
   bool hide_on_silence_{false};
+  bool mapped_{false};
   // Cava method
-  auto onUpdate(const ::cava::audio_raw& input) -> void;
+  void pauseResume();
+  auto onUpdate(const CavaBackend::AudioRaw& input) -> void;
   auto onSilence() -> void;
-  // Member variable to store the shared pointer
-  std::shared_ptr<::cava::audio_raw> m_data_;
-  GLuint shaderProgram_;
+  auto onBackendConfigChanged() -> void;
+  void cacheConfigParams(const ::cava::config_params& src);
+  // Member variable to store audio data
+  CavaBackend::AudioRaw m_data_;
+  GLuint shaderProgram_{0};
   // OpenGL variables
-  GLuint fbo_;
-  GLuint texture_;
+  GLuint fbo_{0};
+  GLuint texture_{0};
+  GLuint vbo_{0};
+  GLuint ibo_{0};
+  GLuint vao_{0};
   GLint uniform_bars_;
   GLint uniform_previous_bars_;
   GLint uniform_bars_count_;
   GLint uniform_time_;
+  GLint uniform_input_texture_;
   // Methods
   void onRealize();
   bool onRender(const Glib::RefPtr<Gdk::GLContext>& context);
@@ -39,5 +67,13 @@ class CavaGLSL final : public AModule, public Gtk::GLArea {
   void initSurface();
   void initGLSL();
   GLuint loadShader(const std::string& fileName, GLenum type);
+  void cleanupGL();
+
+  // ModuleActionMap
+  static const std::map<std::string, Action> actionMap_;
+
+  sigc::connection audio_raw_update_conn_;
+  sigc::connection silence_conn_;
+  sigc::connection config_changed_conn_;
 };
 }  // namespace waybar::modules::cava

include/modules/cava/cavaRaw.hpp

@@ -1,30 +1,38 @@
 #pragma once
 
+#include <map>
+#include <string>
+
+#include <sigc++/connection.h>
+
 #include "ALabel.hpp"
 #include "cava_backend.hpp"
 
 namespace waybar::modules::cava {
 
-class Cava final : public ALabel, public sigc::trackable {
+class CavaRaw final : public ALabel {
  public:
-  Cava(const std::string&, const Json::Value&);
-  ~Cava() = default;
+  CavaRaw(const std::string&, const Json::Value&);
+  ~CavaRaw();
   auto doAction(const std::string& name) -> void override;
 
  private:
+  using Action = void (CavaRaw::*)();
+
   std::shared_ptr<CavaBackend> backend_;
   // Text to display
-  Glib::ustring label_text_{""};
+  Glib::ustring label_text_;
   bool silence_{false};
   bool hide_on_silence_{false};
-  std::string format_silent_{""};
-  int ascii_range_{0};
+  std::string format_silent_;
   // Cava method
-  void pause_resume();
+  void pauseResume();
   auto onUpdate(const std::string& input) -> void;
   auto onSilence() -> void;
   // ModuleActionMap
-  static inline std::map<const std::string, void (waybar::modules::cava::Cava::* const)()>
-      actionMap_{{"mode", &waybar::modules::cava::Cava::pause_resume}};
+  static const std::map<std::string, Action> actionMap_;
+
+  sigc::connection update_conn_;
+  sigc::connection silence_conn_;
 };
 }  // namespace waybar::modules::cava

include/modules/cava/cava_backend.hpp

@@ -1,8 +1,17 @@
 #pragma once
 
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <vector>
+
 #include <json/json.h>
 #include <sigc++/sigc++.h>
 
+#include "util/SafeSignal.hpp"
 #include "util/sleeper_thread.hpp"
 
 namespace cava {
@@ -21,7 +30,6 @@ extern "C" {
 }  // namespace cava
 
 namespace waybar::modules::cava {
-using namespace std::literals::chrono_literals;
 
 class CavaBackend final {
  public:
@@ -29,19 +37,38 @@ class CavaBackend final {
 
   virtual ~CavaBackend();
   // Methods
-  int getAsciiRange();
+  int getAsciiRange() const;
   void doPauseResume();
-  void Update();
-  const struct ::cava::config_params* getPrm();
-  std::chrono::milliseconds getFrameTimeMilsec();
+  void update();
+  const ::cava::config_params& getPrm() const;
+  std::chrono::milliseconds getFrameTimeMilsec() const;
+
+  struct AudioRaw {
+    std::vector<float> bars_raw;
+    std::vector<float> previous_bars_raw;
+    int number_of_bars = 0;
+
+    AudioRaw() = default;
+    explicit AudioRaw(const ::cava::audio_raw& raw) {
+      number_of_bars = raw.number_of_bars;
+      if (raw.bars_raw != nullptr && number_of_bars > 0) {
+        bars_raw.assign(raw.bars_raw, raw.bars_raw + number_of_bars);
+      }
+      if (raw.previous_bars_raw != nullptr && number_of_bars > 0) {
+        previous_bars_raw.assign(raw.previous_bars_raw, raw.previous_bars_raw + number_of_bars);
+      }
+    }
+  };
 
   // Signal accessor
-  using type_signal_update = sigc::signal<void(const std::string&)>;
-  type_signal_update signal_update();
-  using type_signal_audio_raw_update = sigc::signal<void(const ::cava::audio_raw&)>;
-  type_signal_audio_raw_update signal_audio_raw_update();
-  using type_signal_silence = sigc::signal<void()>;
-  type_signal_silence signal_silence();
+  using SignalUpdate = SafeSignal<const std::string&>;
+  SignalUpdate& signalUpdate();
+  using SignalAudioRawUpdate = SafeSignal<AudioRaw>;
+  SignalAudioRawUpdate& signalAudioRawUpdate();
+  using SignalSilence = SafeSignal<>;
+  SignalSilence& signalSilence();
+  using SignalConfigChanged = SafeSignal<>;
+  SignalConfigChanged& signalConfigChanged();
 
  private:
   CavaBackend(const Json::Value& config);
@@ -49,36 +76,78 @@ class CavaBackend final {
   util::SleeperThread out_thread_;
 
   // Cava API to read audio source
-  ::cava::ptr input_source_{NULL};
+  ::cava::ptr input_source_{nullptr};
 
   struct ::cava::error_s error_{};          // cava errors
   struct ::cava::config_params prm_{};      // cava parameters
   struct ::cava::audio_raw audio_raw_{};    // cava handled raw audio data(is based on audio_data)
   struct ::cava::audio_data audio_data_{};  // cava audio data
-  struct ::cava::cava_plan* plan_{NULL};    //{new cava_plan{}};
+  struct ::cava::cava_plan* plan_{nullptr};    //{new cava_plan{}};
 
   std::chrono::seconds fetch_input_delay_{4};
-  // Delay to handle audio source
-  std::chrono::milliseconds frame_time_milsec_{1s};
 
-  const Json::Value& config_;
+  struct AdaptiveDelay {
+    std::chrono::milliseconds delay;
+    std::chrono::seconds delta{0};
+
+    explicit AdaptiveDelay(std::chrono::milliseconds initial = std::chrono::seconds(1))
+        : delay(initial) {}
+
+    bool increase() {
+      if (delta == std::chrono::seconds{0}) {
+        delta += std::chrono::seconds{1};
+        delay += delta;
+        return true;
+      }
+      return false;
+    }
+
+    bool decrease() {
+      if (delta > std::chrono::seconds{0}) {
+        delay -= delta;
+        delta -= std::chrono::seconds{1};
+        return true;
+      }
+      return false;
+    }
+
+    std::chrono::milliseconds current() const { return delay; }
+
+    void reset(std::chrono::milliseconds new_delay) {
+      delay = new_delay;
+      delta = std::chrono::seconds{0};
+    }
+  };
+
+  AdaptiveDelay adaptive_delay_;
+
+  Json::Value config_;
   int re_paint_{0};
   bool silence_{false};
   bool silence_prev_{false};
-  std::chrono::seconds suspend_silence_delay_{0};
   int sleep_counter_{0};
   std::string output_{};
   // Methods
   void invoke();
   void execute();
-  bool isSilence();
+  bool isSilent();
   void doUpdate(bool force = false);
   void loadConfig();
   void freeBackend();
 
   // Signal
-  type_signal_update m_signal_update_;
-  type_signal_audio_raw_update m_signal_audio_raw_;
-  type_signal_silence m_signal_silence_;
+  SignalUpdate m_signal_update_;
+  SignalAudioRawUpdate m_signal_audio_raw_;
+  SignalSilence m_signal_silence_;
+  SignalConfigChanged m_signal_config_changed_;
+
+  std::atomic<bool> shutdown_{false};
+  bool audio_raw_initialized_{false};
+  mutable std::recursive_mutex state_mutex_;
+
+  // Synchronization for joining read_thread_ during destruction
+  bool read_thread_exited_{false};
+  mutable std::mutex read_thread_exit_mutex_;
+  std::condition_variable read_thread_exit_cv_;
 };
 }  // namespace waybar::modules::cava

include/modules/cava/cava_frontend.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <memory>
+
 #ifdef HAVE_LIBCAVA
 #include "cavaRaw.hpp"
 #include "cava_backend.hpp"
@@ -9,16 +11,16 @@
 #endif
 
 namespace waybar::modules::cava {
-AModule* getModule(const std::string& id, const Json::Value& config) {
+inline std::unique_ptr<AModule> getModule(const std::string& id, const Json::Value& config) {
 #ifdef HAVE_LIBCAVA
   const std::shared_ptr<CavaBackend> backend_{waybar::modules::cava::CavaBackend::inst(config)};
-  switch (backend_->getPrm()->output) {
+  switch (backend_->getPrm().output) {
 #ifdef HAVE_LIBCAVAGLSL
     case ::cava::output_method::OUTPUT_SDL_GLSL:
-      return new waybar::modules::cava::CavaGLSL(id, config);
+      return std::make_unique<waybar::modules::cava::CavaGLSL>(id, config);
 #endif
     default:
-      return new waybar::modules::cava::Cava(id, config);
+      return std::make_unique<waybar::modules::cava::CavaRaw>(id, config);
   }
 #else
   throw std::runtime_error("Unknown module");

src/factory.cpp

@@ -372,7 +372,7 @@ waybar::AModule* waybar::Factory::makeModule(const std::string& name,
     }
 #endif
     if (ref == "cava") {
-      return waybar::modules::cava::getModule(id, config_[name]);
+      return waybar::modules::cava::getModule(id, config_[name]).release();
     }
 #ifdef HAVE_SYSTEMD_MONITOR
     if (ref == "systemd-failed-units") {

src/modules/cava/cavaGLSL.cpp

@@ -2,88 +2,214 @@
 
 #include <spdlog/spdlog.h>
 
+#include <algorithm>
+#include <cstdio>
+#include <cstring>
 #include <fstream>
+#include <sstream>
+#include <vector>
+
+const std::map<std::string, waybar::modules::cava::CavaGLSL::Action>
+    waybar::modules::cava::CavaGLSL::actionMap_{{"mode", &CavaGLSL::pauseResume}};
 
 waybar::modules::cava::CavaGLSL::CavaGLSL(const std::string& id, const Json::Value& config)
     : AModule(config, "cavaGLSL", id, false, false),
       backend_{waybar::modules::cava::CavaBackend::inst(config)} {
-  set_name(name_);
+  gl_area_.set_name(name_);
   if (config_["hide_on_silence"].isBool()) hide_on_silence_ = config_["hide_on_silence"].asBool();
   if (!id.empty()) {
-    get_style_context()->add_class(id);
+    gl_area_.get_style_context()->add_class(id);
   }
-  get_style_context()->add_class(MODULE_CLASS);
+  gl_area_.get_style_context()->add_class(MODULE_CLASS);
 
-  set_use_es(true);
-  //  set_auto_render(true);
-  signal_realize().connect(sigc::mem_fun(*this, &CavaGLSL::onRealize));
-  signal_render().connect(sigc::mem_fun(*this, &CavaGLSL::onRender), false);
+  gl_area_.set_use_es(true);
+  gl_area_.signal_realize().connect(sigc::mem_fun(*this, &CavaGLSL::onRealize));
+  gl_area_.signal_render().connect(sigc::mem_fun(*this, &CavaGLSL::onRender), false);
+  gl_area_.signal_map().connect([this]() { mapped_ = true; });
+  gl_area_.signal_unmap().connect([this]() { mapped_ = false; });
 
-  // Get parameters_config struct from the backend
-  prm_ = *backend_->getPrm();
+  cacheConfigParams(backend_->getPrm());
 
-  // Set widget length
   int length{0};
   if (config_["min-length"].isUInt())
     length = config_["min-length"].asUInt();
   else if (config_["max-length"].isUInt())
     length = config_["max-length"].asUInt();
   else
-    length = prm_.sdl_width;
+    length = sdl_width_;
 
-  set_size_request(length, prm_.sdl_height);
+  gl_area_.set_size_request(length, sdl_height_);
 
-  // Subscribe for changes
-  backend_->signal_audio_raw_update().connect(sigc::mem_fun(*this, &CavaGLSL::onUpdate));
-  // Subscribe for silence
-  backend_->signal_silence().connect(sigc::mem_fun(*this, &CavaGLSL::onSilence));
-  event_box_.add(*this);
+  audio_raw_update_conn_ =
+      backend_->signalAudioRawUpdate().connect(sigc::mem_fun(*this, &CavaGLSL::onUpdate));
+  silence_conn_ = backend_->signalSilence().connect(sigc::mem_fun(*this, &CavaGLSL::onSilence));
+  config_changed_conn_ =
+      backend_->signalConfigChanged().connect(sigc::mem_fun(*this, &CavaGLSL::onBackendConfigChanged));
+  event_box_.add(gl_area_);
 }
 
-auto waybar::modules::cava::CavaGLSL::onUpdate(const ::cava::audio_raw& input) -> void {
-  Glib::signal_idle().connect_once([this, input]() {
-    m_data_ = std::make_shared<::cava::audio_raw>(input);
-    if (silence_) {
-      get_style_context()->remove_class("silent");
-      if (!get_style_context()->has_class("updated")) get_style_context()->add_class("updated");
-      show();
-      silence_ = false;
-    }
+waybar::modules::cava::CavaGLSL::~CavaGLSL() {
+  audio_raw_update_conn_.disconnect();
+  silence_conn_.disconnect();
+  config_changed_conn_.disconnect();
 
-    queue_render();
-  });
+  if (gl_area_.get_realized()) {
+    gl_area_.make_current();
+    cleanupGL();
+  }
+}
+
+void waybar::modules::cava::CavaGLSL::cleanupGL() {
+  if (shaderProgram_ != 0) {
+    glDeleteProgram(shaderProgram_);
+    shaderProgram_ = 0;
+  }
+  if (fbo_ != 0) {
+    glDeleteFramebuffers(1, &fbo_);
+    fbo_ = 0;
+  }
+  if (texture_ != 0) {
+    glDeleteTextures(1, &texture_);
+    texture_ = 0;
+  }
+  if (vbo_ != 0) {
+    glDeleteBuffers(1, &vbo_);
+    vbo_ = 0;
+  }
+  if (ibo_ != 0) {
+    glDeleteBuffers(1, &ibo_);
+    ibo_ = 0;
+  }
+  if (vao_ != 0) {
+    glDeleteVertexArrays(1, &vao_);
+    vao_ = 0;
+  }
+}
+
+auto waybar::modules::cava::CavaGLSL::doAction(const std::string& name) -> void {
+  auto it = actionMap_.find(name);
+  if (it != actionMap_.end() && it->second) {
+    (this->*it->second)();
+  } else {
+    spdlog::error("CavaGLSL. Unsupported action \"{0}\"", name);
+  }
+}
+
+void waybar::modules::cava::CavaGLSL::pauseResume() { backend_->doPauseResume(); }
+
+auto waybar::modules::cava::CavaGLSL::onUpdate(const CavaBackend::AudioRaw& input) -> void {
+  m_data_ = input;
+  if (silence_) {
+    gl_area_.get_style_context()->remove_class("silent");
+    if (!gl_area_.get_style_context()->has_class("updated"))
+      gl_area_.get_style_context()->add_class("updated");
+    gl_area_.show();
+    silence_ = false;
+  }
+
+  if (mapped_) {
+    gl_area_.queue_render();
+  }
 }
 
 auto waybar::modules::cava::CavaGLSL::onSilence() -> void {
-  Glib::signal_idle().connect_once([this]() {
-    if (!silence_) {
-      if (get_style_context()->has_class("updated")) get_style_context()->remove_class("updated");
+  if (!silence_) {
+    if (gl_area_.get_style_context()->has_class("updated"))
+      gl_area_.get_style_context()->remove_class("updated");
 
-      if (hide_on_silence_) hide();
-      silence_ = true;
-      get_style_context()->add_class("silent");
-      // Set clear color to black
-      glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
-      queue_render();
+    if (hide_on_silence_) gl_area_.hide();
+    silence_ = true;
+    gl_area_.get_style_context()->add_class("silent");
+  }
+}
+
+void waybar::modules::cava::CavaGLSL::cacheConfigParams(const ::cava::config_params& src) {
+  sdl_width_ = src.sdl_width;
+  sdl_height_ = src.sdl_height;
+  bar_width_ = src.bar_width;
+  bar_spacing_ = src.bar_spacing;
+  gradient_count_ = src.gradient_count;
+  vertex_shader_ = src.vertex_shader ? src.vertex_shader : "";
+  fragment_shader_ = src.fragment_shader ? src.fragment_shader : "";
+  bcolor_ = src.bcolor ? src.bcolor : "";
+  color_ = src.color ? src.color : "";
+  for (size_t i = 0; i < gradient_colors_.size(); ++i) {
+    gradient_colors_[i] = (src.gradient_colors[i] ? src.gradient_colors[i] : "");
+  }
+}
+
+auto waybar::modules::cava::CavaGLSL::onBackendConfigChanged() -> void {
+  auto new_prm = backend_->getPrm();
+
+  bool dimensions_changed =
+      (new_prm.sdl_width != sdl_width_) || (new_prm.sdl_height != sdl_height_);
+
+  bool shaders_changed = false;
+  std::string new_vertex = new_prm.vertex_shader ? new_prm.vertex_shader : "";
+  std::string new_fragment = new_prm.fragment_shader ? new_prm.fragment_shader : "";
+  shaders_changed = (vertex_shader_ != new_vertex) || (fragment_shader_ != new_fragment);
+
+  bool surface_changed = false;
+  if (new_prm.bar_width != bar_width_) surface_changed = true;
+  if (new_prm.bar_spacing != bar_spacing_) surface_changed = true;
+  if (new_prm.gradient_count != gradient_count_) surface_changed = true;
+  std::string new_bcolor = new_prm.bcolor ? new_prm.bcolor : "";
+  if (bcolor_ != new_bcolor) surface_changed = true;
+  std::string new_color = new_prm.color ? new_prm.color : "";
+  if (color_ != new_color) surface_changed = true;
+  for (size_t i = 0; i < gradient_colors_.size(); ++i) {
+    std::string new_grad = new_prm.gradient_colors[i] ? new_prm.gradient_colors[i] : "";
+    if (gradient_colors_[i] != new_grad) {
+      surface_changed = true;
+      break;
     }
-  });
+  }
+
+  cacheConfigParams(new_prm);
+
+  if ((dimensions_changed || shaders_changed) && gl_area_.get_realized()) {
+    gl_area_.make_current();
+    cleanupGL();
+    initShaders();
+    if (shaderProgram_ != 0) {
+      initGLSL();
+      initSurface();
+    }
+  } else if (surface_changed && gl_area_.get_realized()) {
+    gl_area_.make_current();
+    glUseProgram(shaderProgram_);
+    initSurface();
+  }
+
+  int length{0};
+  if (config_["min-length"].isUInt())
+    length = config_["min-length"].asUInt();
+  else if (config_["max-length"].isUInt())
+    length = config_["max-length"].asUInt();
+  else
+    length = sdl_width_;
+
+  gl_area_.set_size_request(length, sdl_height_);
 }
 
 bool waybar::modules::cava::CavaGLSL::onRender(const Glib::RefPtr<Gdk::GLContext>& context) {
-  if (!m_data_) return true;
+  if (m_data_.bars_raw.empty() || shaderProgram_ == 0) return true;
+
+  glUseProgram(shaderProgram_);
+  glBindVertexArray(vao_);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
   glActiveTexture(GL_TEXTURE0);
   glBindTexture(GL_TEXTURE_2D, texture_);
-  glUniform1i(glGetUniformLocation(shaderProgram_, "inputTexture"), 0);
+  glUniform1i(uniform_input_texture_, 0);
 
-  glUniform1fv(uniform_bars_, m_data_->number_of_bars, m_data_->bars_raw);
-  glUniform1fv(uniform_previous_bars_, m_data_->number_of_bars, m_data_->previous_bars_raw);
-  glUniform1i(uniform_bars_count_, m_data_->number_of_bars);
-  ++frame_counter;
-  glUniform1f(uniform_time_, (frame_counter / backend_->getFrameTimeMilsec().count()) / 1e3);
+  glUniform1fv(uniform_bars_, m_data_.number_of_bars, m_data_.bars_raw.data());
+  glUniform1fv(uniform_previous_bars_, m_data_.number_of_bars, m_data_.previous_bars_raw.data());
+  glUniform1i(uniform_bars_count_, m_data_.number_of_bars);
+  ++frame_counter_;
+  glUniform1f(uniform_time_,
+              static_cast<float>(frame_counter_) * backend_->getFrameTimeMilsec().count() / 1000.0f);
 
-  //  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, nullptr);
 
   glBindFramebuffer(GL_FRAMEBUFFER, fbo_);
@@ -94,21 +220,35 @@ bool waybar::modules::cava::CavaGLSL::onRender(const Glib::RefPtr<Gdk::GLContext
 }
 
 void waybar::modules::cava::CavaGLSL::onRealize() {
-  make_current();
+  gl_area_.make_current();
+  cleanupGL();
   initShaders();
+  if (shaderProgram_ == 0) {
+    return;
+  }
   initGLSL();
   initSurface();
 }
 
-struct colors {
+struct Colors {
   uint16_t R;
   uint16_t G;
   uint16_t B;
 };
 
-static void parse_color(char* color_string, struct colors* color) {
-  if (color_string[0] == '#') {
-    sscanf(++color_string, "%02hx%02hx%02hx", &color->R, &color->G, &color->B);
+static void parse_color(const char* color_string, struct Colors* color) {
+  if (color_string == nullptr) {
+    return;
+  }
+  if (color_string[0] != '#') {
+    return;
+  }
+  if (std::strlen(color_string) < 7) {
+    spdlog::warn("Invalid color string '{}': expected #RRGGBB", color_string);
+    return;
+  }
+  if (std::sscanf(color_string + 1, "%02hx%02hx%02hx", &color->R, &color->G, &color->B) != 3) {
+    spdlog::warn("Failed to parse color string '{}'", color_string);
   }
 }
 
@@ -123,49 +263,44 @@ void waybar::modules::cava::CavaGLSL::initGLSL() {
   GLfloat vertexData[]{-1.0f, -1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f};
   GLint indexData[]{0, 1, 2, 3};
 
-  GLuint gVBO{0};
-  glGenBuffers(1, &gVBO);
-  glBindBuffer(GL_ARRAY_BUFFER, gVBO);
+  glGenBuffers(1, &vbo_);
+  glBindBuffer(GL_ARRAY_BUFFER, vbo_);
   glBufferData(GL_ARRAY_BUFFER, 2 * 4 * sizeof(GLfloat), vertexData, GL_STATIC_DRAW);
 
-  GLuint gIBO{0};
-  glGenBuffers(1, &gIBO);
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gIBO);
+  glGenBuffers(1, &ibo_);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_);
   glBufferData(GL_ELEMENT_ARRAY_BUFFER, 4 * sizeof(GLuint), indexData, GL_STATIC_DRAW);
 
-  GLuint gVAO{0};
-  glGenVertexArrays(1, &gVAO);
-  glBindVertexArray(gVAO);
+  glGenVertexArrays(1, &vao_);
+  glBindVertexArray(vao_);
   glEnableVertexAttribArray(gVertexPos2DLocation);
 
-  glBindBuffer(GL_ARRAY_BUFFER, gVBO);
+  glBindBuffer(GL_ARRAY_BUFFER, vbo_);
   glVertexAttribPointer(gVertexPos2DLocation, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), nullptr);
 
-  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gIBO);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_);
 
   glGenFramebuffers(1, &fbo_);
   glBindFramebuffer(GL_FRAMEBUFFER, fbo_);
 
-  // Create a texture to attach the framebuffer
   glGenTextures(1, &texture_);
   glBindTexture(GL_TEXTURE_2D, texture_);
-  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, prm_.sdl_width, prm_.sdl_height, 0, GL_RGBA,
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, sdl_width_, sdl_height_, 0, GL_RGBA,
                GL_UNSIGNED_BYTE, nullptr);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
   glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_, 0);
 
-  // Check is framebuffer is complete
   if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
     spdlog::error("{0}. Framebuffer not complete", name_);
   }
 
-  // Unbind the framebuffer
   glBindFramebuffer(GL_FRAMEBUFFER, 0);
   uniform_bars_ = glGetUniformLocation(shaderProgram_, "bars");
   uniform_previous_bars_ = glGetUniformLocation(shaderProgram_, "previous_bars");
   uniform_bars_count_ = glGetUniformLocation(shaderProgram_, "bars_count");
   uniform_time_ = glGetUniformLocation(shaderProgram_, "shader_time");
+  uniform_input_texture_ = glGetUniformLocation(shaderProgram_, "inputTexture");
 
   GLuint err{glGetError()};
   if (err != 0) {
@@ -174,32 +309,32 @@ void waybar::modules::cava::CavaGLSL::initGLSL() {
 }
 
 void waybar::modules::cava::CavaGLSL::initSurface() {
-  colors color = {0};
+  Colors color = {0};
   GLint uniform_bg_col{glGetUniformLocation(shaderProgram_, "bg_color")};
-  parse_color(prm_.bcolor, &color);
-  glUniform3f(uniform_bg_col, (float)color.R / 255.0, (float)color.G / 255.0,
-              (float)color.B / 255.0);
+  parse_color(bcolor_.c_str(), &color);
+  glUniform3f(uniform_bg_col, static_cast<float>(color.R) / 255.0f, static_cast<float>(color.G) / 255.0f,
+              static_cast<float>(color.B) / 255.0f);
   GLint uniform_fg_col{glGetUniformLocation(shaderProgram_, "fg_color")};
-  parse_color(prm_.color, &color);
-  glUniform3f(uniform_fg_col, (float)color.R / 255.0, (float)color.G / 255.0,
-              (float)color.B / 255.0);
+  parse_color(color_.c_str(), &color);
+  glUniform3f(uniform_fg_col, static_cast<float>(color.R) / 255.0f, static_cast<float>(color.G) / 255.0f,
+              static_cast<float>(color.B) / 255.0f);
   GLint uniform_res{glGetUniformLocation(shaderProgram_, "u_resolution")};
-  glUniform3f(uniform_res, (float)prm_.sdl_width, (float)prm_.sdl_height, 0.0f);
+  glUniform3f(uniform_res, static_cast<float>(sdl_width_), static_cast<float>(sdl_height_), 0.0f);
   GLint uniform_bar_width{glGetUniformLocation(shaderProgram_, "bar_width")};
-  glUniform1i(uniform_bar_width, prm_.bar_width);
+  glUniform1i(uniform_bar_width, bar_width_);
   GLint uniform_bar_spacing{glGetUniformLocation(shaderProgram_, "bar_spacing")};
-  glUniform1i(uniform_bar_spacing, prm_.bar_spacing);
+  glUniform1i(uniform_bar_spacing, bar_spacing_);
   GLint uniform_gradient_count{glGetUniformLocation(shaderProgram_, "gradient_count")};
-  glUniform1i(uniform_gradient_count, prm_.gradient_count);
+  glUniform1i(uniform_gradient_count, std::max(0, gradient_count_));
   GLint uniform_gradient_colors{glGetUniformLocation(shaderProgram_, "gradient_colors")};
-  GLfloat gradient_colors[8][3];
-  for (int i{0}; i < prm_.gradient_count; ++i) {
-    parse_color(prm_.gradient_colors[i], &color);
-    gradient_colors[i][0] = (float)color.R / 255.0;
-    gradient_colors[i][1] = (float)color.G / 255.0;
-    gradient_colors[i][2] = (float)color.B / 255.0;
+  GLfloat gradient_colors[8][3] = {};
+  for (int i{0}; i < gradient_count_; ++i) {
+    parse_color(gradient_colors_[i].c_str(), &color);
+    gradient_colors[i][0] = static_cast<float>(color.R) / 255.0f;
+    gradient_colors[i][1] = static_cast<float>(color.G) / 255.0f;
+    gradient_colors[i][2] = static_cast<float>(color.B) / 255.0f;
   }
-  glUniform3fv(uniform_gradient_colors, 8, (const GLfloat*)gradient_colors);
+  glUniform3fv(uniform_gradient_colors, std::max(0, std::min(gradient_count_, 8)), &gradient_colors[0][0]);
 
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, nullptr);
@@ -207,9 +342,23 @@ void waybar::modules::cava::CavaGLSL::initSurface() {
 
 void waybar::modules::cava::CavaGLSL::initShaders() {
   shaderProgram_ = glCreateProgram();
+  if (shaderProgram_ == 0) {
+    spdlog::error("{0}. Failed to create shader program", name_);
+    gl_area_.hide();
+    return;
+  }
 
-  GLuint vertexShader{loadShader(prm_.vertex_shader, GL_VERTEX_SHADER)};
-  GLuint fragmentShader{loadShader(prm_.fragment_shader, GL_FRAGMENT_SHADER)};
+  GLuint vertexShader{loadShader(vertex_shader_, GL_VERTEX_SHADER)};
+  GLuint fragmentShader{loadShader(fragment_shader_, GL_FRAGMENT_SHADER)};
+
+  if (vertexShader == 0 || fragmentShader == 0) {
+    if (vertexShader != 0) glDeleteShader(vertexShader);
+    if (fragmentShader != 0) glDeleteShader(fragmentShader);
+    glDeleteProgram(shaderProgram_);
+    shaderProgram_ = 0;
+    gl_area_.hide();
+    return;
+  }
 
   glAttachShader(shaderProgram_, vertexShader);
   glAttachShader(shaderProgram_, fragmentShader);
@@ -219,14 +368,18 @@ void waybar::modules::cava::CavaGLSL::initShaders() {
   glDeleteShader(vertexShader);
   glDeleteShader(fragmentShader);
 
-  // Check for linking errors
-  GLint success, len;
+  GLint success{0};
   glGetProgramiv(shaderProgram_, GL_LINK_STATUS, &success);
   if (!success) {
+    GLint len{0};
     glGetProgramiv(shaderProgram_, GL_INFO_LOG_LENGTH, &len);
-    GLchar* infoLog{(char*)'\0'};
-    glGetProgramInfoLog(shaderProgram_, len, &len, infoLog);
-    spdlog::error("{0}. Shader linking error: {1}", name_, infoLog);
+    std::vector<GLchar> infoLog(len + 1);
+    glGetProgramInfoLog(shaderProgram_, len, nullptr, infoLog.data());
+    spdlog::error("{0}. Shader linking error: {1}", name_, infoLog.data());
+    glDeleteProgram(shaderProgram_);
+    shaderProgram_ = 0;
+    gl_area_.hide();
+    return;
   }
 
   glReleaseShaderCompiler();
@@ -236,35 +389,37 @@ void waybar::modules::cava::CavaGLSL::initShaders() {
 GLuint waybar::modules::cava::CavaGLSL::loadShader(const std::string& fileName, GLenum type) {
   spdlog::debug("{0}. loadShader: {1}", name_, fileName);
 
-  // Read shader source code from the file
   std::ifstream shaderFile{fileName};
-
   if (!shaderFile.is_open()) {
     spdlog::error("{0}. Could not open shader file: {1}", name_, fileName);
+    return 0;
   }
 
   std::ostringstream buffer;
-  buffer << shaderFile.rdbuf();  // read file content into stringstream
+  buffer << shaderFile.rdbuf();
   std::string str{buffer.str()};
-  const char* shaderSource = str.c_str();
   shaderFile.close();
 
   GLuint shaderID{glCreateShader(type)};
-  if (shaderID == 0) spdlog::error("{0}. Error creating shader type: {0}", type);
+  if (shaderID == 0) {
+    spdlog::error("{0}. Error creating shader type: {1}", name_, type);
+    return 0;
+  }
+
+  const char* shaderSource = str.c_str();
   glShaderSource(shaderID, 1, &shaderSource, nullptr);
   glCompileShader(shaderID);
 
-  // Check for compilation errors
-  GLint success, len;
-
+  GLint success{0};
   glGetShaderiv(shaderID, GL_COMPILE_STATUS, &success);
-
   if (!success) {
+    GLint len{0};
     glGetShaderiv(shaderID, GL_INFO_LOG_LENGTH, &len);
-
-    GLchar* infoLog{(char*)'\0'};
-    glGetShaderInfoLog(shaderID, len, nullptr, infoLog);
-    spdlog::error("{0}. Shader compilation error in {1}: {2}", name_, fileName, infoLog);
+    std::vector<GLchar> infoLog(len + 1);
+    glGetShaderInfoLog(shaderID, len, nullptr, infoLog.data());
+    spdlog::error("{0}. Shader compilation error in {1}: {2}", name_, fileName, infoLog.data());
+    glDeleteShader(shaderID);
+    return 0;
   }
 
   return shaderID;

src/modules/cava/cavaRaw.cpp

@@ -2,59 +2,68 @@
 
 #include <spdlog/spdlog.h>
 
-waybar::modules::cava::Cava::Cava(const std::string& id, const Json::Value& config)
+const std::map<std::string, waybar::modules::cava::CavaRaw::Action>
+    waybar::modules::cava::CavaRaw::actionMap_{{"mode", &CavaRaw::pauseResume}};
+
+waybar::modules::cava::CavaRaw::CavaRaw(const std::string& id, const Json::Value& config)
     : ALabel(config, "cava", id, "{}", 60, false, false, false),
       backend_{waybar::modules::cava::CavaBackend::inst(config)} {
   if (config_["hide_on_silence"].isBool()) hide_on_silence_ = config_["hide_on_silence"].asBool();
   if (config_["format_silent"].isString()) format_silent_ = config_["format_silent"].asString();
 
-  ascii_range_ = backend_->getAsciiRange();
-  backend_->signal_update().connect(sigc::mem_fun(*this, &Cava::onUpdate));
-  backend_->signal_silence().connect(sigc::mem_fun(*this, &Cava::onSilence));
-  backend_->Update();
+  update_conn_ = backend_->signalUpdate().connect(sigc::mem_fun(*this, &CavaRaw::onUpdate));
+  silence_conn_ = backend_->signalSilence().connect(sigc::mem_fun(*this, &CavaRaw::onSilence));
+  backend_->update();
 }
 
-auto waybar::modules::cava::Cava::doAction(const std::string& name) -> void {
-  if ((actionMap_[name])) {
-    (this->*actionMap_[name])();
-  } else
+waybar::modules::cava::CavaRaw::~CavaRaw() {
+  update_conn_.disconnect();
+  silence_conn_.disconnect();
+}
+
+auto waybar::modules::cava::CavaRaw::doAction(const std::string& name) -> void {
+  auto it = actionMap_.find(name);
+  if (it != actionMap_.end() && it->second) {
+    (this->*it->second)();
+  } else {
     spdlog::error("Cava. Unsupported action \"{0}\"", name);
+  }
 }
 
 // Cava actions
-void waybar::modules::cava::Cava::pause_resume() { backend_->doPauseResume(); }
-auto waybar::modules::cava::Cava::onUpdate(const std::string& input) -> void {
-  Glib::signal_idle().connect_once([this, input]() {
-    if (silence_) {
-      silence_ = false;
-      label_.get_style_context()->remove_class("silent");
-      if (!label_.get_style_context()->has_class("updated"))
-        label_.get_style_context()->add_class("updated");
-    }
-    label_text_.clear();
-    for (auto& ch : input)
-      label_text_.append(getIcon((ch > ascii_range_) ? ascii_range_ : ch, "", ascii_range_ + 1));
+void waybar::modules::cava::CavaRaw::pauseResume() { backend_->doPauseResume(); }
+auto waybar::modules::cava::CavaRaw::onUpdate(const std::string& input) -> void {
+  if (silence_) {
+    silence_ = false;
+    label_.get_style_context()->remove_class("silent");
+    if (!label_.get_style_context()->has_class("updated"))
+      label_.get_style_context()->add_class("updated");
+  }
+  label_text_.clear();
+  auto ascii_range = backend_->getAsciiRange();
+  for (auto& ch : input) {
+    auto uch = static_cast<unsigned char>(ch);
+    label_text_.append(getIcon((uch > ascii_range) ? ascii_range : uch, "", ascii_range + 1));
+  }
 
-    label_.set_markup(label_text_);
-    label_.show();
-    ALabel::update();
-  });
+  label_.set_markup(label_text_);
+  label_.show();
+  ALabel::update();
 }
 
-auto waybar::modules::cava::Cava::onSilence() -> void {
-  Glib::signal_idle().connect_once([this]() {
-    if (!silence_) {
-      if (label_.get_style_context()->has_class("updated"))
-        label_.get_style_context()->remove_class("updated");
+auto waybar::modules::cava::CavaRaw::onSilence() -> void {
+  if (!silence_) {
+    if (label_.get_style_context()->has_class("updated"))
+      label_.get_style_context()->remove_class("updated");
 
-      if (hide_on_silence_) {
-        // Clear the label markup before hiding to prevent GTK from rendering a NULL Pango layout
-        label_.set_markup("");
-        label_.hide();
-      } else if (config_["format_silent"].isString())
-        label_.set_markup(format_silent_);
-      silence_ = true;
-      label_.get_style_context()->add_class("silent");
+    if (hide_on_silence_) {
+      // Clear the label markup before hiding to prevent GTK from rendering a NULL Pango layout
+      label_.set_markup("");
+      label_.hide();
+    } else if (!format_silent_.empty()) {
+      label_.set_markup(format_silent_);
     }
-  });
+    silence_ = true;
+    label_.get_style_context()->add_class("silent");
+  }
 }

src/modules/cava/cava_backend.cpp

@@ -2,8 +2,23 @@
 
 #include <spdlog/spdlog.h>
 
+#include <algorithm>
 #include <stdexcept>
 
+namespace {
+struct CavaConfigGuard {
+  ::cava::config_params* prm;
+  bool released = false;
+  explicit CavaConfigGuard(::cava::config_params* p) : prm(p) {}
+  ~CavaConfigGuard() {
+    if (!released && prm) {
+      free_config(prm);
+    }
+  }
+  void release() { released = true; }
+};
+}  // namespace
+
 std::shared_ptr<waybar::modules::cava::CavaBackend> waybar::modules::cava::CavaBackend::inst(
     const Json::Value& config) {
   static auto* backend = new CavaBackend(config);
@@ -12,69 +27,84 @@ std::shared_ptr<waybar::modules::cava::CavaBackend> waybar::modules::cava::CavaB
 }
 
 waybar::modules::cava::CavaBackend::CavaBackend(const Json::Value& config) : config_(config) {
-  // Load waybar module config
   loadConfig();
-  // Read audio source trough cava API. Cava orginizes this process via infinity loop
   read_thread_ = [this] {
-    try {
-      input_source_(&audio_data_);
-    } catch (const std::runtime_error& e) {
-      spdlog::warn("Cava backend. Read source error: {0}", e.what());
+    while (read_thread_.isRunning()) {
+      try {
+        if (input_source_) {
+          input_source_(&audio_data_);
+        }
+      } catch (const std::exception& e) {
+        spdlog::warn("Cava backend. Read source error: {0}", e.what());
+      }
+      if (!read_thread_.isRunning()) break;
+      read_thread_.sleep_for(fetch_input_delay_);
+      if (!read_thread_.isRunning()) break;
+      try {
+        loadConfig();
+      } catch (const std::exception& e) {
+        spdlog::error("{}", e.what());
+      }
     }
-    read_thread_.sleep_for(fetch_input_delay_);
-    // loadConfig() now throws on failure; contain it so a runtime config error
-    // logs instead of terminating the process (#4456).
-    try {
-      loadConfig();
-    } catch (const std::exception& e) {
-      spdlog::error("{}", e.what());
+    {
+      std::lock_guard<std::mutex> lk(read_thread_exit_mutex_);
+      read_thread_exited_ = true;
     }
+    read_thread_exit_cv_.notify_one();
   };
-  // Write outcoming data. Emit signals
   out_thread_ = [this] {
-    doUpdate(false);
-    out_thread_.sleep_for(frame_time_milsec_);
+    try {
+      doUpdate(false);
+    } catch (const std::exception& e) {
+      spdlog::error("Cava backend. Output thread error: {0}", e.what());
+    }
+    out_thread_.sleep_for(adaptive_delay_.current());
   };
 }
 
 waybar::modules::cava::CavaBackend::~CavaBackend() {
+  {
+    std::lock_guard<std::recursive_mutex> lock(state_mutex_);
+    shutdown_ = true;
+  }
+
+  pthread_mutex_lock(&audio_data_.lock);
+  audio_data_.terminate = 1;
+  pthread_mutex_unlock(&audio_data_.lock);
+
   out_thread_.stop();
   read_thread_.stop();
 
+  std::unique_lock<std::mutex> lk(read_thread_exit_mutex_);
+  if (!read_thread_exit_cv_.wait_for(lk, std::chrono::milliseconds(100),
+                                     [this] { return read_thread_exited_; })) {
+    spdlog::debug(
+        "Cava backend: read thread still blocked in input_source() on shutdown. "
+        "Proceeding with cleanup.");
+  }
+
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
   freeBackend();
 }
 
-static bool upThreadDelay(std::chrono::milliseconds& delay, std::chrono::seconds& delta) {
-  if (delta == std::chrono::seconds{0}) {
-    delta += std::chrono::seconds{1};
-    delay += delta;
-    return true;
-  }
-  return false;
-}
-
-static bool downThreadDelay(std::chrono::milliseconds& delay, std::chrono::seconds& delta) {
-  if (delta > std::chrono::seconds{0}) {
-    delay -= delta;
-    delta -= std::chrono::seconds{1};
-    return true;
-  }
-  return false;
-}
-
-bool waybar::modules::cava::CavaBackend::isSilence() {
+bool waybar::modules::cava::CavaBackend::isSilent() {
+  pthread_mutex_lock(&audio_data_.lock);
+  bool silent = true;
   for (int i{0}; i < audio_data_.input_buffer_size; ++i) {
     if (audio_data_.cava_in[i]) {
-      return false;
+      silent = false;
+      break;
     }
   }
-
-  return true;
+  pthread_mutex_unlock(&audio_data_.lock);
+  return silent;
 }
 
-int waybar::modules::cava::CavaBackend::getAsciiRange() { return prm_.ascii_range; }
+int waybar::modules::cava::CavaBackend::getAsciiRange() const {
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
+  return prm_.ascii_range;
+}
 
-// Process: execute cava
 void waybar::modules::cava::CavaBackend::invoke() {
   pthread_mutex_lock(&audio_data_.lock);
   ::cava::cava_execute(audio_data_.cava_in, audio_data_.samples_counter, audio_raw_.cava_out,
@@ -83,7 +113,6 @@ void waybar::modules::cava::CavaBackend::invoke() {
   pthread_mutex_unlock(&audio_data_.lock);
 }
 
-// Do transformation under raw data
 void waybar::modules::cava::CavaBackend::execute() {
   invoke();
   audio_raw_fetch(&audio_raw_, &prm_, &re_paint_, plan_);
@@ -99,183 +128,228 @@ void waybar::modules::cava::CavaBackend::execute() {
 }
 
 void waybar::modules::cava::CavaBackend::doPauseResume() {
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
   pthread_mutex_lock(&audio_data_.lock);
   if (audio_data_.suspendFlag) {
     audio_data_.suspendFlag = false;
     pthread_cond_broadcast(&audio_data_.resumeCond);
-    downThreadDelay(frame_time_milsec_, suspend_silence_delay_);
+    adaptive_delay_.decrease();
   } else {
     audio_data_.suspendFlag = true;
-    upThreadDelay(frame_time_milsec_, suspend_silence_delay_);
+    adaptive_delay_.increase();
   }
   pthread_mutex_unlock(&audio_data_.lock);
-  Update();
+  update();
 }
 
-waybar::modules::cava::CavaBackend::type_signal_update
-waybar::modules::cava::CavaBackend::signal_update() {
+waybar::modules::cava::CavaBackend::SignalUpdate&
+waybar::modules::cava::CavaBackend::signalUpdate() {
   return m_signal_update_;
 }
 
-waybar::modules::cava::CavaBackend::type_signal_audio_raw_update
-waybar::modules::cava::CavaBackend::signal_audio_raw_update() {
+waybar::modules::cava::CavaBackend::SignalAudioRawUpdate&
+waybar::modules::cava::CavaBackend::signalAudioRawUpdate() {
   return m_signal_audio_raw_;
 }
 
-waybar::modules::cava::CavaBackend::type_signal_silence
-waybar::modules::cava::CavaBackend::signal_silence() {
+waybar::modules::cava::CavaBackend::SignalSilence&
+waybar::modules::cava::CavaBackend::signalSilence() {
   return m_signal_silence_;
 }
 
-void waybar::modules::cava::CavaBackend::Update() { doUpdate(true); }
+waybar::modules::cava::CavaBackend::SignalConfigChanged&
+waybar::modules::cava::CavaBackend::signalConfigChanged() {
+  return m_signal_config_changed_;
+}
+
+void waybar::modules::cava::CavaBackend::update() { doUpdate(true); }
 
 void waybar::modules::cava::CavaBackend::doUpdate(bool force) {
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
+  if (!plan_ || !input_source_) return;
   if (audio_data_.suspendFlag && !force) return;
 
-  silence_ = isSilence();
+  silence_ = isSilent();
   if (!silence_) sleep_counter_ = 0;
 
   if (silence_ && prm_.sleep_timer != 0) {
     if (sleep_counter_ <=
-        (int)(std::chrono::milliseconds(prm_.sleep_timer * 1s) / frame_time_milsec_)) {
+        static_cast<int>(std::chrono::milliseconds(prm_.sleep_timer * std::chrono::seconds(1)) /
+              adaptive_delay_.current())) {
       ++sleep_counter_;
       silence_ = false;
     }
   }
 
   if (!silence_ || prm_.sleep_timer == 0) {
-    if (downThreadDelay(frame_time_milsec_, suspend_silence_delay_)) Update();
+    while (adaptive_delay_.decrease()) {}
     execute();
     if (re_paint_ == 1 || force || prm_.continuous_rendering) {
       m_signal_update_.emit(output_);
-      m_signal_audio_raw_.emit(audio_raw_);
+      m_signal_audio_raw_.emit(AudioRaw{audio_raw_});
     }
   } else {
-    if (upThreadDelay(frame_time_milsec_, suspend_silence_delay_)) Update();
+    while (adaptive_delay_.increase()) {}
     if (silence_ != silence_prev_ || force) m_signal_silence_.emit();
   }
   silence_prev_ = silence_;
 }
 
 void waybar::modules::cava::CavaBackend::freeBackend() {
-  if (plan_ != NULL) {
+  input_source_ = nullptr;
+
+  if (plan_ != nullptr) {
     cava_destroy(plan_);
-    plan_ = NULL;
+    plan_ = nullptr;
   }
 
-  audio_raw_clean(&audio_raw_);
+  if (audio_raw_initialized_) {
+    audio_raw_clean(&audio_raw_);
+    audio_raw_initialized_ = false;
+  }
   pthread_mutex_lock(&audio_data_.lock);
   audio_data_.terminate = 1;
   pthread_mutex_unlock(&audio_data_.lock);
   free_config(&prm_);
+  prm_ = {};
   free(audio_data_.source);
+  audio_data_.source = nullptr;
   free(audio_data_.cava_in);
+  audio_data_.cava_in = nullptr;
 }
 
 void waybar::modules::cava::CavaBackend::loadConfig() {
-  freeBackend();
-  // Load waybar module config
-  char cfgPath[PATH_MAX];
-  cfgPath[0] = '\0';
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
+  if (shutdown_.load()) {
+    return;
+  }
 
-  if (config_["cava_config"].isString()) strcpy(cfgPath, config_["cava_config"].asString().data());
-  // Load cava config
+  const Json::Value& cfg = config_;
+
+  struct ::cava::config_params new_prm{};
+  CavaConfigGuard new_prm_guard(&new_prm);
+  std::vector<char> cfgPath(PATH_MAX, '\0');
+  if (cfg["cava_config"].isString()) {
+    const std::string& s = cfg["cava_config"].asString();
+    auto len = std::min(s.size(), static_cast<size_t>(PATH_MAX - 1));
+    std::copy_n(s.begin(), len, cfgPath.begin());
+    cfgPath[len] = '\0';
+  }
   error_.length = 0;
 
-  if (!load_config(cfgPath, &prm_, &error_)) {
-    // Throw, don't exit(): a bad config must disable only the cava module, not
-    // kill the whole bar (#4456). Caught by the factory (ctor) / read_thread_.
+  if (!load_config(cfgPath.data(), &new_prm, &error_)) {
     throw std::runtime_error(std::string{"cava backend: error loading config: "} + error_.message);
   }
 
-  // Override cava parameters by the user config
-  prm_.inAtty = 0;
-  auto const output{prm_.output};
-  // prm_.output = ::cava::output_method::OUTPUT_RAW;
-  if (prm_.data_format) free(prm_.data_format);
-  // Default to ascii for format-icons output; allow user override
-  prm_.data_format = strdup(
-      config_["data_format"].isString() ? config_["data_format"].asString().c_str() : "ascii");
-  if (config_["raw_target"].isString()) {
-    if (prm_.raw_target) free(prm_.raw_target);
-    prm_.raw_target = strdup(config_["raw_target"].asString().c_str());
+  new_prm.inAtty = 0;
+  auto const output{new_prm.output};
+  if (new_prm.data_format) free(new_prm.data_format);
+  new_prm.data_format = strdup(
+      cfg["data_format"].isString() ? cfg["data_format"].asString().c_str() : "ascii");
+  if (cfg["raw_target"].isString()) {
+    if (new_prm.raw_target) free(new_prm.raw_target);
+    new_prm.raw_target = strdup(cfg["raw_target"].asString().c_str());
   }
-  prm_.ascii_range = config_["format-icons"].size() - 1;
-
-  if (config_["bar_spacing"].isInt()) prm_.bar_spacing = config_["bar_spacing"].asInt();
-  if (config_["bar_width"].isInt()) prm_.bar_width = config_["bar_width"].asInt();
-  if (config_["bar_height"].isInt()) prm_.bar_height = config_["bar_height"].asInt();
-  prm_.orientation = ::cava::ORIENT_TOP;
-  prm_.xaxis = ::cava::xaxis_scale::NONE;
-  prm_.mono_opt = ::cava::AVERAGE;
-  prm_.autobars = 0;
-  if (config_["gravity"].isInt()) prm_.gravity = config_["gravity"].asInt();
-  if (config_["integral"].isInt()) prm_.integral = config_["integral"].asInt();
-
-  if (config_["framerate"].isInt()) prm_.framerate = config_["framerate"].asInt();
-  // Calculate delay for Update() thread
-  frame_time_milsec_ = std::chrono::milliseconds((int)(1e3 / prm_.framerate));
-  if (config_["autosens"].isInt()) prm_.autosens = config_["autosens"].asInt();
-  if (config_["sensitivity"].isInt()) prm_.sens = config_["sensitivity"].asInt();
-  if (config_["bars"].isInt()) prm_.fixedbars = config_["bars"].asInt();
-  if (config_["lower_cutoff_freq"].isNumeric())
-    prm_.lower_cut_off = config_["lower_cutoff_freq"].asLargestInt();
-  if (config_["higher_cutoff_freq"].isNumeric())
-    prm_.upper_cut_off = config_["higher_cutoff_freq"].asLargestInt();
-  if (config_["sleep_timer"].isInt()) prm_.sleep_timer = config_["sleep_timer"].asInt();
-  if (config_["method"].isString())
-    prm_.input = ::cava::input_method_by_name(config_["method"].asString().c_str());
-  if (config_["source"].isString()) {
-    if (prm_.audio_source) free(prm_.audio_source);
-    prm_.audio_source = strdup(config_["source"].asString().c_str());
-  }
-  if (config_["sample_rate"].isNumeric()) prm_.samplerate = config_["sample_rate"].asLargestInt();
-  if (config_["sample_bits"].isInt()) prm_.samplebits = config_["sample_bits"].asInt();
-  if (config_["stereo"].isBool()) prm_.stereo = config_["stereo"].asBool();
-  if (config_["reverse"].isBool()) prm_.reverse = config_["reverse"].asBool();
-  if (config_["bar_delimiter"].isInt()) prm_.bar_delim = config_["bar_delimiter"].asInt();
-  if (config_["monstercat"].isBool()) prm_.monstercat = config_["monstercat"].asBool();
-  if (config_["waves"].isBool()) prm_.waves = config_["waves"].asBool();
-  if (config_["noise_reduction"].isDouble())
-    prm_.noise_reduction = config_["noise_reduction"].asDouble();
-  if (config_["input_delay"].isInt())
-    fetch_input_delay_ = std::chrono::seconds(config_["input_delay"].asInt());
-  if (config_["gradient"].isInt()) prm_.gradient = config_["gradient"].asInt();
-  if (prm_.gradient == 0)
-    prm_.gradient_count = 0;
-  else if (config_["gradient_count"].isInt())
-    prm_.gradient_count = config_["gradient_count"].asInt();
-  if (config_["sdl_width"].isInt()) prm_.sdl_width = config_["sdl_width"].asInt();
-  if (config_["sdl_height"].isInt()) prm_.sdl_height = config_["sdl_height"].asInt();
-
-  audio_raw_.height = prm_.ascii_range;
-  audio_data_.format = -1;
-  audio_data_.rate = 0;
-  audio_data_.samples_counter = 0;
-  audio_data_.channels = 2;
-  audio_data_.IEEE_FLOAT = 0;
-  audio_data_.input_buffer_size = BUFFER_SIZE * audio_data_.channels;
-  audio_data_.cava_buffer_size = audio_data_.input_buffer_size * 8;
-  audio_data_.terminate = 0;
-  audio_data_.suspendFlag = false;
-  input_source_ = get_input(&audio_data_, &prm_);
-
-  if (!input_source_) {
-    throw std::runtime_error("cava backend: API didn't provide an input audio source");
+  {
+    auto icon_count = cfg["format-icons"].size();
+    new_prm.ascii_range = (icon_count > 0) ? static_cast<int>(icon_count) - 1 : 0;
   }
 
-  prm_.output = ::cava::output_method::OUTPUT_RAW;
+  if (cfg["bar_spacing"].isInt()) new_prm.bar_spacing = cfg["bar_spacing"].asInt();
+  if (cfg["bar_width"].isInt()) new_prm.bar_width = cfg["bar_width"].asInt();
+  if (cfg["bar_height"].isInt()) new_prm.bar_height = cfg["bar_height"].asInt();
+  new_prm.orientation = ::cava::ORIENT_TOP;
+  new_prm.xaxis = ::cava::xaxis_scale::NONE;
+  new_prm.mono_opt = ::cava::AVERAGE;
+  new_prm.autobars = 0;
+  if (cfg["gravity"].isInt()) new_prm.gravity = cfg["gravity"].asInt();
+  if (cfg["integral"].isInt()) new_prm.integral = cfg["integral"].asInt();
 
-  // Make cava parameters configuration
-  // Init cava plan, audio_raw structure
-  audio_raw_init(&audio_data_, &audio_raw_, &prm_, &plan_);
-  if (!plan_) spdlog::error("cava backend plan is not provided");
-  audio_raw_.previous_frame[0] = -1;  // For first Update() call need to rePaint text message
+  if (cfg["framerate"].isInt()) new_prm.framerate = cfg["framerate"].asInt();
+  if (cfg["autosens"].isInt()) new_prm.autosens = cfg["autosens"].asInt();
+  if (cfg["sensitivity"].isInt()) new_prm.sens = cfg["sensitivity"].asInt();
+  if (cfg["bars"].isInt()) new_prm.fixedbars = cfg["bars"].asInt();
+  if (cfg["lower_cutoff_freq"].isNumeric())
+    new_prm.lower_cut_off = cfg["lower_cutoff_freq"].asLargestInt();
+  if (cfg["higher_cutoff_freq"].isNumeric())
+    new_prm.upper_cut_off = cfg["higher_cutoff_freq"].asLargestInt();
+  if (cfg["sleep_timer"].isInt()) new_prm.sleep_timer = cfg["sleep_timer"].asInt();
+  if (cfg["method"].isString())
+    new_prm.input = ::cava::input_method_by_name(cfg["method"].asString().c_str());
+  if (cfg["source"].isString()) {
+    if (new_prm.audio_source) free(new_prm.audio_source);
+    new_prm.audio_source = strdup(cfg["source"].asString().c_str());
+  }
+  if (cfg["sample_rate"].isNumeric()) new_prm.samplerate = cfg["sample_rate"].asLargestInt();
+  if (cfg["sample_bits"].isInt()) new_prm.samplebits = cfg["sample_bits"].asInt();
+  if (cfg["stereo"].isBool()) new_prm.stereo = cfg["stereo"].asBool();
+  if (cfg["reverse"].isBool()) new_prm.reverse = cfg["reverse"].asBool();
+  if (cfg["bar_delimiter"].isInt()) new_prm.bar_delim = cfg["bar_delimiter"].asInt();
+  if (cfg["monstercat"].isBool()) new_prm.monstercat = cfg["monstercat"].asBool();
+  if (cfg["waves"].isBool()) new_prm.waves = cfg["waves"].asBool();
+  if (cfg["noise_reduction"].isDouble())
+    new_prm.noise_reduction = cfg["noise_reduction"].asDouble();
+  if (cfg["input_delay"].isInt())
+    fetch_input_delay_ = std::chrono::seconds(cfg["input_delay"].asInt());
+  if (cfg["gradient"].isInt()) new_prm.gradient = cfg["gradient"].asInt();
+  if (new_prm.gradient == 0)
+    new_prm.gradient_count = 0;
+  else if (cfg["gradient_count"].isInt())
+    new_prm.gradient_count = cfg["gradient_count"].asInt();
+  if (cfg["sdl_width"].isInt()) new_prm.sdl_width = cfg["sdl_width"].asInt();
+  if (cfg["sdl_height"].isInt()) new_prm.sdl_height = cfg["sdl_height"].asInt();
 
+  if (new_prm.framerate <= 0) {
+    throw std::runtime_error(std::string{"cava backend: framerate must be positive, got: "} +
+                             std::to_string(new_prm.framerate));
+  }
+
+  adaptive_delay_.reset(std::chrono::milliseconds(static_cast<int>(1e3 / new_prm.framerate)));
+  freeBackend();
+
+  try {
+    audio_raw_.height = new_prm.ascii_range;
+    audio_data_.format = -1;
+    audio_data_.rate = 0;
+    audio_data_.samples_counter = 0;
+    audio_data_.channels = 2;
+    audio_data_.IEEE_FLOAT = 0;
+    audio_data_.input_buffer_size = BUFFER_SIZE * audio_data_.channels;
+    audio_data_.cava_buffer_size = audio_data_.input_buffer_size * 8;
+    audio_data_.terminate = 0;
+    audio_data_.suspendFlag = false;
+
+    input_source_ = get_input(&audio_data_, &new_prm);
+    if (!input_source_) {
+      throw std::runtime_error("cava backend: API didn't provide an input audio source");
+    }
+
+    new_prm.output = ::cava::output_method::OUTPUT_RAW;
+
+    audio_raw_init(&audio_data_, &audio_raw_, &new_prm, &plan_);
+    if (!plan_) {
+      throw std::runtime_error("cava backend plan is not provided");
+    }
+    audio_raw_.previous_frame[0] = -1;
+    audio_raw_initialized_ = true;
+  } catch (...) {
+    freeBackend();
+    throw;
+  }
+
+  prm_ = new_prm;
+  new_prm_guard.release();
   prm_.output = output;
+
+  m_signal_config_changed_.emit();
 }
 
-const struct ::cava::config_params* waybar::modules::cava::CavaBackend::getPrm() { return &prm_; }
-std::chrono::milliseconds waybar::modules::cava::CavaBackend::getFrameTimeMilsec() {
-  return frame_time_milsec_;
-};
+const ::cava::config_params& waybar::modules::cava::CavaBackend::getPrm() const {
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
+  return prm_;
+}
+
+std::chrono::milliseconds waybar::modules::cava::CavaBackend::getFrameTimeMilsec() const {
+  std::lock_guard<std::recursive_mutex> lock(state_mutex_);
+  return adaptive_delay_.current();
+}