[fix] update MiniRTC: refactor IceAgent to improve stability

src/app/daemon.cpp

@@ -34,9 +34,16 @@
 #endif
 
 #ifndef _WIN32
-Daemon* Daemon::instance_ = nullptr;
+volatile std::sig_atomic_t Daemon::stop_requested_ = 0;
 #endif
 
+namespace {
+constexpr int kRestartDelayMs = 1000;
+#ifndef _WIN32
+constexpr int kWaitPollIntervalMs = 200;
+#endif
+}  // namespace
+
 // get executable file path
 static std::string GetExecutablePath() {
 #ifdef _WIN32
@@ -66,33 +73,35 @@ static std::string GetExecutablePath() {
   return "";
 }
 
-Daemon::Daemon(const std::string& name)
-    : name_(name)
-#ifdef _WIN32
-      ,
-      running_(false)
-#else
-      ,
-      running_(true)
+Daemon::Daemon(const std::string& name) : name_(name), running_(false) {}
+
+void Daemon::stop() {
+  running_.store(false);
+#ifndef _WIN32
+  stop_requested_ = 1;
 #endif
-{
 }
 
-void Daemon::stop() { running_ = false; }
-
-bool Daemon::isRunning() const { return running_; }
+bool Daemon::isRunning() const {
+#ifndef _WIN32
+  return running_.load() && (stop_requested_ == 0);
+#else
+  return running_.load();
+#endif
+}
 
 bool Daemon::start(MainLoopFunc loop) {
 #ifdef _WIN32
-  running_ = true;
+  running_.store(true);
   return runWithRestart(loop);
 #elif __APPLE__
   // macOS: Use child process monitoring (like Windows) to preserve GUI
-  running_ = true;
+  stop_requested_ = 0;
+  running_.store(true);
   return runWithRestart(loop);
 #else
   // linux: Daemonize first, then run with restart monitoring
-  instance_ = this;
+  stop_requested_ = 0;
 
   // check if running from terminal before fork
   bool from_terminal =
@@ -134,29 +143,13 @@ bool Daemon::start(MainLoopFunc loop) {
   }
 
   // set up signal handlers
-  signal(SIGTERM, [](int) {
-    if (instance_) instance_->stop();
-  });
-  signal(SIGINT, [](int) {
-    if (instance_) instance_->stop();
-  });
+  signal(SIGTERM, [](int) { stop_requested_ = 1; });
+  signal(SIGINT, [](int) { stop_requested_ = 1; });
 
   // ignore SIGPIPE
   signal(SIGPIPE, SIG_IGN);
 
-  // set up SIGCHLD handler to reap zombie processes
-  struct sigaction sa_chld;
-  sa_chld.sa_handler = [](int) {
-    // reap zombie processes
-    while (waitpid(-1, nullptr, WNOHANG) > 0) {
-      // continue until no more zombie children
-    }
-  };
-  sigemptyset(&sa_chld.sa_mask);
-  sa_chld.sa_flags = SA_RESTART | SA_NOCLDSTOP;
-  sigaction(SIGCHLD, &sa_chld, nullptr);
-
-  running_ = true;
+  running_.store(true);
   return runWithRestart(loop);
 #endif
 }
@@ -204,8 +197,7 @@ bool Daemon::runWithRestart(MainLoopFunc loop) {
         restart_count++;
         std::cerr << "Exception caught, restarting... (attempt "
                   << restart_count << ")" << std::endl;
-        std::this_thread::sleep_for(
-            std::chrono::milliseconds(DAEMON_DEFAULT_RESTART_DELAY_MS));
+        std::this_thread::sleep_for(std::chrono::milliseconds(kRestartDelayMs));
       }
     }
     return true;
@@ -237,27 +229,41 @@ bool Daemon::runWithRestart(MainLoopFunc loop) {
     if (!success) {
       std::cerr << "Failed to create child process, error: " << GetLastError()
                 << std::endl;
-      std::this_thread::sleep_for(
-          std::chrono::milliseconds(DAEMON_DEFAULT_RESTART_DELAY_MS));
+      std::this_thread::sleep_for(std::chrono::milliseconds(kRestartDelayMs));
       restart_count++;
       continue;
     }
 
+    while (isRunning()) {
+      DWORD wait_result = WaitForSingleObject(pi.hProcess, 200);
+      if (wait_result == WAIT_OBJECT_0) {
+        break;
+      }
+      if (wait_result == WAIT_FAILED) {
+        std::cerr << "Failed waiting child process, error: " << GetLastError()
+                  << std::endl;
+        break;
+      }
+    }
+
+    if (!isRunning()) {
+      TerminateProcess(pi.hProcess, 1);
+      WaitForSingleObject(pi.hProcess, 3000);
+    }
+
     DWORD exit_code = 0;
-    WaitForSingleObject(pi.hProcess, INFINITE);
     GetExitCodeProcess(pi.hProcess, &exit_code);
     CloseHandle(pi.hProcess);
     CloseHandle(pi.hThread);
 
-    if (exit_code == 0) {
+    if (!isRunning() || exit_code == 0) {
       break;  // normal exit
     }
     restart_count++;
     std::cerr << "Child process exited with code " << exit_code
               << ", restarting... (attempt " << restart_count << ")"
               << std::endl;
-    std::this_thread::sleep_for(
-        std::chrono::milliseconds(DAEMON_DEFAULT_RESTART_DELAY_MS));
+    std::this_thread::sleep_for(std::chrono::milliseconds(kRestartDelayMs));
 #else
     // linux: use fork + exec to create child process
     pid_t pid = fork();
@@ -266,21 +272,39 @@ bool Daemon::runWithRestart(MainLoopFunc loop) {
       _exit(1);  // exec failed
     } else if (pid > 0) {
       int status = 0;
-      pid_t waited_pid = waitpid(pid, &status, 0);
+      pid_t waited_pid = -1;
+      while (isRunning()) {
+        waited_pid = waitpid(pid, &status, WNOHANG);
+        if (waited_pid == pid) {
+          break;
+        }
+        if (waited_pid < 0 && errno != EINTR) {
+          break;
+        }
+        std::this_thread::sleep_for(
+            std::chrono::milliseconds(kWaitPollIntervalMs));
+      }
+
+      if (!isRunning() && waited_pid != pid) {
+        kill(pid, SIGTERM);
+        waited_pid = waitpid(pid, &status, 0);
+      }
 
       if (waited_pid < 0) {
+        if (!isRunning()) {
+          break;
+        }
         restart_count++;
         std::cerr << "waitpid failed, errno: " << errno
                   << ", restarting... (attempt " << restart_count << ")"
                   << std::endl;
-        std::this_thread::sleep_for(
-            std::chrono::milliseconds(DAEMON_DEFAULT_RESTART_DELAY_MS));
+        std::this_thread::sleep_for(std::chrono::milliseconds(kRestartDelayMs));
         continue;
       }
 
       if (WIFEXITED(status)) {
         int exit_code = WEXITSTATUS(status);
-        if (exit_code == 0) {
+        if (!isRunning() || exit_code == 0) {
           break;  // normal exit
         }
         restart_count++;
@@ -288,6 +312,9 @@ bool Daemon::runWithRestart(MainLoopFunc loop) {
                   << ", restarting... (attempt " << restart_count << ")"
                   << std::endl;
       } else if (WIFSIGNALED(status)) {
+        if (!isRunning()) {
+          break;
+        }
         restart_count++;
         std::cerr << "Child process crashed with signal " << WTERMSIG(status)
                   << ", restarting... (attempt " << restart_count << ")"
@@ -298,12 +325,10 @@ bool Daemon::runWithRestart(MainLoopFunc loop) {
                      "(attempt "
                   << restart_count << ")" << std::endl;
       }
-      std::this_thread::sleep_for(
-          std::chrono::milliseconds(DAEMON_DEFAULT_RESTART_DELAY_MS));
+      std::this_thread::sleep_for(std::chrono::milliseconds(kRestartDelayMs));
     } else {
       std::cerr << "Failed to fork child process" << std::endl;
-      std::this_thread::sleep_for(
-          std::chrono::milliseconds(DAEMON_DEFAULT_RESTART_DELAY_MS));
+      std::this_thread::sleep_for(std::chrono::milliseconds(kRestartDelayMs));
       restart_count++;
     }
 #endif

src/app/daemon.h

@@ -7,11 +7,11 @@
 #ifndef _DAEMON_H_
 #define _DAEMON_H_
 
+#include <atomic>
+#include <csignal>
 #include <functional>
 #include <string>
 
-#define DAEMON_DEFAULT_RESTART_DELAY_MS 1000
-
 class Daemon {
  public:
   using MainLoopFunc = std::function<void()>;
@@ -28,12 +28,10 @@ class Daemon {
   std::string name_;
   bool runWithRestart(MainLoopFunc loop);
 
-#ifdef _WIN32
-  bool running_;
-#else
-  static Daemon* instance_;
-  volatile bool running_;
+#ifndef _WIN32
+  static volatile std::sig_atomic_t stop_requested_;
 #endif
+  std::atomic<bool> running_;
 };
 
-#endif
+#endif

src/device_controller/keyboard/linux/keyboard_capturer.cpp

@@ -1,5 +1,8 @@
 #include "keyboard_capturer.h"
 
+#include <errno.h>
+#include <poll.h>
+
 #include "keyboard_converter.h"
 #include "rd_log.h"
 
@@ -10,7 +13,7 @@ static void* g_user_ptr = nullptr;
 
 static int KeyboardEventHandler(Display* display, XEvent* event) {
   if (event->xkey.type == KeyPress || event->xkey.type == KeyRelease) {
-    KeySym keySym = XKeycodeToKeysym(display, event->xkey.keycode, 0);
+    KeySym keySym = XLookupKeysym(&event->xkey, 0);
     int key_code = XKeysymToKeycode(display, keySym);
     bool is_key_down = (event->xkey.type == KeyPress);
 
@@ -21,7 +24,9 @@ static int KeyboardEventHandler(Display* display, XEvent* event) {
   return 0;
 }
 
-KeyboardCapturer::KeyboardCapturer() : display_(nullptr), running_(true) {
+KeyboardCapturer::KeyboardCapturer()
+    : display_(nullptr), root_(0), running_(false) {
+  XInitThreads();
   display_ = XOpenDisplay(nullptr);
   if (!display_) {
     LOG_ERROR("Failed to open X display.");
@@ -29,35 +34,87 @@ KeyboardCapturer::KeyboardCapturer() : display_(nullptr), running_(true) {
 }
 
 KeyboardCapturer::~KeyboardCapturer() {
+  Unhook();
+
   if (display_) {
     XCloseDisplay(display_);
+    display_ = nullptr;
   }
 }
 
 int KeyboardCapturer::Hook(OnKeyAction on_key_action, void* user_ptr) {
+  if (!display_) {
+    LOG_ERROR("Display not initialized.");
+    return -1;
+  }
+
   g_on_key_action = on_key_action;
   g_user_ptr = user_ptr;
 
-  XSelectInput(display_, DefaultRootWindow(display_),
-               KeyPressMask | KeyReleaseMask);
-
-  while (running_) {
-    XEvent event;
-    XNextEvent(display_, &event);
-    KeyboardEventHandler(display_, &event);
+  if (running_) {
+    return 0;
   }
 
+  root_ = DefaultRootWindow(display_);
+  XSelectInput(display_, root_, KeyPressMask | KeyReleaseMask);
+  XFlush(display_);
+
+  running_ = true;
+  const int x11_fd = ConnectionNumber(display_);
+  event_thread_ = std::thread([this, x11_fd]() {
+    while (running_) {
+      while (running_ && XPending(display_) > 0) {
+        XEvent event;
+        XNextEvent(display_, &event);
+        KeyboardEventHandler(display_, &event);
+      }
+
+      if (!running_) {
+        break;
+      }
+
+      struct pollfd pfd = {x11_fd, POLLIN, 0};
+      int poll_ret = poll(&pfd, 1, 50);
+      if (poll_ret < 0) {
+        if (errno == EINTR) {
+          continue;
+        }
+        LOG_ERROR("poll for X11 events failed.");
+        running_ = false;
+        break;
+      }
+
+      if (poll_ret == 0) {
+        continue;
+      }
+
+      if ((pfd.revents & (POLLERR | POLLHUP | POLLNVAL)) != 0) {
+        LOG_ERROR("poll got invalid X11 event fd state.");
+        running_ = false;
+        break;
+      }
+
+      if ((pfd.revents & POLLIN) == 0) {
+        continue;
+      }
+    }
+  });
+
   return 0;
 }
 
 int KeyboardCapturer::Unhook() {
+  running_ = false;
+
+  if (event_thread_.joinable()) {
+    event_thread_.join();
+  }
+
   g_on_key_action = nullptr;
   g_user_ptr = nullptr;
 
-  running_ = false;
-
-  if (display_) {
-    XSelectInput(display_, DefaultRootWindow(display_), 0);
+  if (display_ && root_ != 0) {
+    XSelectInput(display_, root_, 0);
     XFlush(display_);
   }
 

src/device_controller/keyboard/linux/keyboard_capturer.h

@@ -11,6 +11,9 @@
 #include <X11/extensions/XTest.h>
 #include <X11/keysym.h>
 
+#include <atomic>
+#include <thread>
+
 #include "device_controller.h"
 
 namespace crossdesk {
@@ -28,7 +31,8 @@ class KeyboardCapturer : public DeviceController {
  private:
   Display* display_;
   Window root_;
-  bool running_;
+  std::atomic<bool> running_;
+  std::thread event_thread_;
 };
 }  // namespace crossdesk
 #endif

src/gui/render.cpp

@@ -7,6 +7,7 @@
 #include <X11/Xlib.h>
 #endif
 
+#include <cstdlib>
 #include <cstring>
 #include <filesystem>
 #include <fstream>
@@ -874,11 +875,38 @@ int Render::AudioDeviceInit() {
   desired_out.format = SDL_AUDIO_S16;
   desired_out.channels = 1;
 
-  output_stream_ = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK,
-                                             &desired_out, nullptr, nullptr);
-  if (!output_stream_) {
+  auto open_stream = [&]() -> bool {
+    output_stream_ = SDL_OpenAudioDeviceStream(
+        SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &desired_out, nullptr, nullptr);
+    return output_stream_ != nullptr;
+  };
+
+  if (!open_stream()) {
+#if defined(__linux__) && !defined(__APPLE__)
+    LOG_WARN(
+        "Failed to open output stream with driver [{}]: {}",
+        getenv("SDL_AUDIODRIVER") ? getenv("SDL_AUDIODRIVER") : "(default)",
+        SDL_GetError());
+
+    setenv("SDL_AUDIODRIVER", "dummy", 1);
+    SDL_QuitSubSystem(SDL_INIT_AUDIO);
+    if (!SDL_InitSubSystem(SDL_INIT_AUDIO)) {
+      LOG_ERROR("Failed to reinitialize SDL audio with dummy driver: {}",
+                SDL_GetError());
+      return -1;
+    }
+
+    if (!open_stream()) {
+      LOG_ERROR("Failed to open output stream with dummy driver: {}",
+                SDL_GetError());
+      return -1;
+    }
+
+    LOG_WARN("Audio output disabled, using SDL dummy audio driver");
+#else
     LOG_ERROR("Failed to open output stream: {}", SDL_GetError());
     return -1;
+#endif
   }
 
   SDL_ResumeAudioDevice(SDL_GetAudioStreamDevice(output_stream_));
@@ -1533,6 +1561,13 @@ void Render::InitializeSettings() {
 }
 
 void Render::InitializeSDL() {
+#if defined(__linux__) && !defined(__APPLE__)
+  if (!getenv("SDL_AUDIODRIVER")) {
+    // Prefer PulseAudio first on Linux to avoid hard ALSA plugin dependency.
+    setenv("SDL_AUDIODRIVER", "pulseaudio", 0);
+  }
+#endif
+
   if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO)) {
     LOG_ERROR("Error: {}", SDL_GetError());
     return;

src/gui/windows/about_window.cpp

@@ -49,8 +49,6 @@ bool Render::OpenUrl(const std::string& url) {
 void Render::Hyperlink(const std::string& label, const std::string& url,
                        const float window_width) {
   ImGui::PushStyleColor(ImGuiCol_Text, IM_COL32(0, 0, 255, 255));
-  ImGui::SetCursorPosX((window_width - ImGui::CalcTextSize(label.c_str()).x) /
-                       2.0f);
   ImGui::TextUnformatted(label.c_str());
   ImGui::PopStyleColor();
 
@@ -106,7 +104,7 @@ int Render::AboutWindow() {
     ImGui::SetCursorPosX(about_window_width * 0.1f);
     ImGui::Text("%s", text.c_str());
 
-    if (update_available_) {
+    if (0) {
       std::string new_version_available =
           localization::new_version_available[localization_language_index_] +
           ": ";
@@ -114,10 +112,15 @@ int Render::AboutWindow() {
       ImGui::Text("%s", new_version_available.c_str());
       std::string access_website =
           localization::access_website[localization_language_index_];
+      ImGui::SetCursorPosX((about_window_width -
+                            ImGui::CalcTextSize(latest_version_.c_str()).x) /
+                           2.0f);
       Hyperlink(latest_version_, "https://crossdesk.cn", about_window_width);
-    }
 
-    ImGui::Text("");
+      ImGui::Spacing();
+    } else {
+      ImGui::Text("%s", "");
+    }
 
     std::string copyright_text = "© 2025 by JUNKUN DI. All rights reserved.";
     std::string license_text = "Licensed under GNU LGPL v3.";

src/gui/windows/update_notification_window.cpp

@@ -103,6 +103,7 @@ int Render::UpdateNotificationWindow() {
         localization::access_website[localization_language_index_] +
         "https://crossdesk.cn";
     ImGui::SetWindowFontScale(0.5f);
+    ImGui::SetCursorPosX(update_notification_window_width * 0.1f);
     Hyperlink(download_text, "https://crossdesk.cn",
               update_notification_window_width);
     ImGui::SetWindowFontScale(1.0f);
@@ -204,4 +205,3 @@ int Render::UpdateNotificationWindow() {
 }
 
 }  // namespace crossdesk
-

src/tools/clipboard.cpp

@@ -452,11 +452,17 @@ static void MonitorThreadFunc() {
   LOG_INFO("Clipboard event monitoring started (Linux XFixes)");
 
   XEvent event;
+  constexpr int kEventPollIntervalMs = 20;
   while (g_monitoring.load()) {
-    XNextEvent(g_x11_display, &event);
-    if (event.type == event_base + XFixesSelectionNotify) {
-      HandleClipboardChange();
+    // Avoid blocking on XNextEvent so StopMonitoring() can stop quickly.
+    while (g_monitoring.load() && XPending(g_x11_display) > 0) {
+      XNextEvent(g_x11_display, &event);
+      if (event.type == event_base + XFixesSelectionNotify) {
+        HandleClipboardChange();
+      }
     }
+    std::this_thread::sleep_for(
+        std::chrono::milliseconds(kEventPollIntervalMs));
   }
 
   XFixesSelectSelectionInput(g_x11_display, event_window, g_clipboard_atom, 0);