[fix] recover Windows capture backends after secure desktop exit

src/screen_capturer/windows/screen_capturer_dxgi.cpp

@@ -244,6 +244,31 @@ bool ScreenCapturerDxgi::CreateDuplicationForMonitor(int monitor_index) {
   return true;
 }
 
+bool ScreenCapturerDxgi::RecreateDuplicationForCurrentMonitor() {
+  ReleaseDuplication();
+  int current_monitor = monitor_index_.load();
+  if (CreateDuplicationForMonitor(current_monitor)) {
+    return true;
+  }
+
+  EnumerateDisplays();
+  if (display_info_list_.empty()) {
+    LOG_ERROR("DXGI: no displays found while recreating duplication");
+    return false;
+  }
+  if (current_monitor < 0 ||
+      current_monitor >= static_cast<int>(display_info_list_.size())) {
+    current_monitor = 0;
+    monitor_index_ = 0;
+  }
+  if (CreateDuplicationForMonitor(current_monitor)) {
+    LOG_INFO("DXGI: recreated duplication for monitor {}",
+             monitor_index_.load());
+    return true;
+  }
+  return false;
+}
+
 void ScreenCapturerDxgi::ReleaseDuplication() {
   staging_.Reset();
   if (duplication_) {
@@ -254,6 +279,8 @@ void ScreenCapturerDxgi::ReleaseDuplication() {
 
 void ScreenCapturerDxgi::CaptureLoop() {
   const int timeout_ms = 33;
+  auto last_duplication_retry =
+      std::chrono::steady_clock::now() - std::chrono::milliseconds(1000);
   while (running_) {
     if (paused_) {
       std::this_thread::sleep_for(std::chrono::milliseconds(10));
@@ -261,6 +288,11 @@ void ScreenCapturerDxgi::CaptureLoop() {
     }
 
     if (!duplication_) {
+      const auto now = std::chrono::steady_clock::now();
+      if (now - last_duplication_retry >= std::chrono::milliseconds(500)) {
+        last_duplication_retry = now;
+        RecreateDuplicationForCurrentMonitor();
+      }
       std::this_thread::sleep_for(std::chrono::milliseconds(10));
       continue;
     }
@@ -274,9 +306,7 @@ void ScreenCapturerDxgi::CaptureLoop() {
     }
     if (FAILED(hr)) {
       LOG_ERROR("DXGI: AcquireNextFrame failed, hr={}", (int)hr);
-      // attempt to recreate duplication
+      RecreateDuplicationForCurrentMonitor();
-      ReleaseDuplication();
-      CreateDuplicationForMonitor(monitor_index_);
       continue;
     }
 
@@ -353,4 +383,4 @@ void ScreenCapturerDxgi::CaptureLoop() {
   }
 }
 
-}  // namespace crossdesk
+}  // namespace crossdesk

src/screen_capturer/windows/screen_capturer_dxgi.h

@@ -50,6 +50,7 @@ class ScreenCapturerDxgi : public ScreenCapturer {
   bool InitializeDxgi();
   void EnumerateDisplays();
   bool CreateDuplicationForMonitor(int monitor_index);
+  bool RecreateDuplicationForCurrentMonitor();
   void CaptureLoop();
   void ReleaseDuplication();
 
@@ -78,4 +79,4 @@ class ScreenCapturerDxgi : public ScreenCapturer {
 };
 }  // namespace crossdesk
 
-#endif
+#endif

src/screen_capturer/windows/screen_capturer_wgc.cpp

@@ -100,8 +100,7 @@ bool ScreenCapturerWgc::IsWgcSupported() {
 }
 
 int ScreenCapturerWgc::Init(const int fps, cb_desktop_data cb) {
-  int error = 0;
+  if (inited_ == true) return 0;
-  if (inited_ == true) return error;
 
   // nv12_frame_ = new unsigned char[rect.right * rect.bottom * 3 / 2];
   // nv12_frame_scaled_ = new unsigned char[1280 * 720 * 3 / 2];
@@ -112,8 +111,18 @@ int ScreenCapturerWgc::Init(const int fps, cb_desktop_data cb) {
 
   if (!IsWgcSupported()) {
     LOG_ERROR("WGC not supported");
-    error = 2;
+    return 2;
-    return error;
+  }
+
+  return RebuildSessions(monitor_index_);
+}
+
+int ScreenCapturerWgc::RebuildSessions(int preferred_monitor_index) {
+  CleanUp();
+
+  if (!IsWgcSupported()) {
+    LOG_ERROR("WGC not supported");
+    return 2;
   }
 
   monitor_ = GetPrimaryMonitor();
@@ -125,6 +134,13 @@ int ScreenCapturerWgc::Init(const int fps, cb_desktop_data cb) {
     return -1;
   }
 
+  if (preferred_monitor_index < 0 ||
+      preferred_monitor_index >= static_cast<int>(display_info_list_.size())) {
+    preferred_monitor_index = 0;
+  }
+  monitor_index_ = preferred_monitor_index;
+
+  int error = 0;
   for (int i = 0; i < display_info_list_.size(); i++) {
     const auto& display = display_info_list_[i];
     LOG_INFO(
@@ -138,20 +154,28 @@ int ScreenCapturerWgc::Init(const int fps, cb_desktop_data cb) {
     sessions_.back().session_->RegisterObserver(this);
     error = sessions_.back().session_->Initialize((HMONITOR)display.handle);
     if (error != 0) {
+      LOG_ERROR("WGC: initialize session {} failed, ret={}", i, error);
+      CleanUp();
       return error;
     }
     sessions_[i].inited_ = true;
-    inited_ = true;
   }
 
   LOG_INFO("Default on monitor {}:{}", monitor_index_,
            display_info_list_[monitor_index_].name);
 
-  initial_monitor_index_ = monitor_index_;
+  if (initial_monitor_index_ < 0 ||
+      initial_monitor_index_ >= static_cast<int>(display_info_list_.size())) {
+    initial_monitor_index_ = monitor_index_;
+  }
+  inited_ = true;
   return 0;
 }
 
-int ScreenCapturerWgc::Destroy() { return 0; }
+int ScreenCapturerWgc::Destroy() {
+  CleanUp();
+  return 0;
+}
 
 int ScreenCapturerWgc::Start(bool show_cursor) {
   if (running_ == true) {
@@ -160,13 +184,37 @@ int ScreenCapturerWgc::Start(bool show_cursor) {
   }
 
   if (inited_ == false) {
-    LOG_ERROR("Screen capturer not inited");
+    const int ret = RebuildSessions(monitor_index_);
-    return 4;
+    if (ret != 0) {
+      LOG_ERROR("Screen capturer not inited");
+      return ret;
+    }
   }
 
+  int ret = StartSessions(show_cursor);
+  if (ret == 0) {
+    return 0;
+  }
+
+  LOG_WARN("WGC: start failed, rebuilding sessions");
+  ret = RebuildSessions(monitor_index_);
+  if (ret != 0) {
+    return ret;
+  }
+  return StartSessions(show_cursor);
+}
+
+int ScreenCapturerWgc::StartSessions(bool show_cursor) {
   bool any_started = false;
+  bool active_started = false;
   int last_error = 0;
-  for (int i = 0; i < sessions_.size(); i++) {
+  int active_monitor = monitor_index_;
+  if (active_monitor < 0 ||
+      active_monitor >= static_cast<int>(sessions_.size())) {
+    active_monitor = 0;
+    monitor_index_ = 0;
+  }
+  for (int i = 0; i < static_cast<int>(sessions_.size()); i++) {
     if (sessions_[i].inited_ == false) {
       LOG_ERROR("Session {} not inited", i);
       continue;
@@ -182,16 +230,27 @@ int ScreenCapturerWgc::Start(bool show_cursor) {
         continue;
       }
 
-      if (i != 0) {
+      if (i != active_monitor) {
         sessions_[i].session_->Pause();
         sessions_[i].paused_ = true;
+      } else {
+        sessions_[i].session_->Resume();
+        sessions_[i].paused_ = false;
       }
       sessions_[i].running_ = true;
       any_started = true;
+      if (i == active_monitor) {
+        active_started = true;
+      }
     }
-    running_ = running_ || any_started;
   }
 
+  running_ = active_started;
+  if (!active_started) {
+    LOG_ERROR("WGC: active session did not start successfully");
+    Stop();
+    return last_error != 0 ? last_error : -1;
+  }
   if (!any_started) {
     LOG_ERROR("WGC: no session started successfully");
     return last_error != 0 ? last_error : -1;
@@ -349,13 +408,16 @@ void ScreenCapturerWgc::OnFrame(const WgcSession::wgc_session_frame& frame,
 }
 
 void ScreenCapturerWgc::CleanUp() {
-  if (inited_) {
+  running_ = false;
-    for (auto& session : sessions_) {
+  for (auto& session : sessions_) {
-      if (session.session_) {
+    if (session.session_) {
-        session.session_->Stop();
+      session.session_->Stop();
-      }
     }
-    sessions_.clear();
   }
+  sessions_.clear();
+  display_info_list_.clear();
+  gs_display_list.clear();
+  monitor_ = nullptr;
+  inited_ = false;
 }
-}  // namespace crossdesk
+}  // namespace crossdesk

src/screen_capturer/windows/screen_capturer_wgc.h

@@ -40,6 +40,8 @@ class ScreenCapturerWgc : public ScreenCapturer,
 
  protected:
   void CleanUp();
+  int RebuildSessions(int preferred_monitor_index);
+  int StartSessions(bool show_cursor);
 
  private:
   HMONITOR monitor_;
@@ -74,4 +76,4 @@ class ScreenCapturerWgc : public ScreenCapturer,
   std::mutex frame_mutex_;
 };
 }  // namespace crossdesk
-#endif
+#endif

src/screen_capturer/windows/screen_capturer_win.cpp

@@ -33,6 +33,8 @@ constexpr DWORD kSecureDesktopStatusPipeTimeoutMs = 500;
 constexpr DWORD kSecureDesktopHelperPipeTimeoutMs = 120;
 constexpr DWORD kSecureDesktopTransientErrorGraceMs = 1500;
 constexpr DWORD kSecureDesktopTransientErrorLogIntervalMs = 5000;
+constexpr DWORD kPostSecureDesktopRestartRetryMs = 500;
+constexpr DWORD kPostSecureDesktopRestartTimeoutMs = 10000;
 constexpr int kSecureDesktopCaptureMinFps = 30;
 constexpr int kSecureDesktopCaptureMaxIntervalMs =
     1000 / kSecureDesktopCaptureMinFps;
@@ -392,21 +394,46 @@ int ScreenCapturerWin::Init(const int fps, cb_desktop_data cb) {
       return;
     }
 
+    const char* raw_display_name = display_name ? display_name : "";
     std::string mapped_name;
     {
       std::lock_guard<std::mutex> lock(alias_mutex_);
-      auto it = label_alias_.find(display_name);
+      auto it = label_alias_.find(raw_display_name);
       if (it != label_alias_.end())
         mapped_name = it->second;
       else
-        mapped_name = display_name;
+        mapped_name = raw_display_name;
     }
     {
       std::lock_guard<std::mutex> lock(alias_mutex_);
       if (canonical_labels_.find(mapped_name) == canonical_labels_.end()) {
+        if (post_secure_desktop_waiting_for_frame_.load(
+                std::memory_order_relaxed) &&
+            !post_secure_desktop_drop_logged_.exchange(
+                true, std::memory_order_relaxed)) {
+          LOG_WARN(
+              "Windows capturer dropping post-secure-desktop frame from "
+              "unknown display: display='{}', mapped='{}', size={}x{}, "
+              "bytes={}",
+              raw_display_name, mapped_name, w, h, size);
+        }
         return;
       }
     }
+    if (post_secure_desktop_waiting_for_frame_.exchange(
+            false, std::memory_order_relaxed)) {
+      const ULONGLONG start_tick =
+          post_secure_desktop_started_tick_.exchange(
+              0, std::memory_order_relaxed);
+      const ULONGLONG elapsed_ms =
+          start_tick == 0 ? 0 : GetTickCount64() - start_tick;
+      post_secure_desktop_drop_logged_.store(false,
+                                             std::memory_order_relaxed);
+      LOG_INFO(
+          "Windows capturer first normal frame after secure desktop: "
+          "display='{}', mapped='{}', size={}x{}, bytes={}, elapsed_ms={}",
+          raw_display_name, mapped_name, w, h, size, elapsed_ms);
+    }
     if (cb_orig_) cb_orig_(data, size, w, h, mapped_name.c_str());
   };
 
@@ -524,6 +551,10 @@ int ScreenCapturerWin::Start(bool show_cursor) {
 
   running_.store(true, std::memory_order_relaxed);
   secure_desktop_capture_active_.store(false, std::memory_order_relaxed);
+  post_secure_desktop_waiting_for_frame_.store(false,
+                                               std::memory_order_relaxed);
+  post_secure_desktop_drop_logged_.store(false, std::memory_order_relaxed);
+  post_secure_desktop_started_tick_.store(0, std::memory_order_relaxed);
   if (!secure_capture_thread_.joinable()) {
     secure_capture_thread_ =
         std::thread([this]() { SecureDesktopCaptureLoop(); });
@@ -534,6 +565,10 @@ int ScreenCapturerWin::Start(bool show_cursor) {
 int ScreenCapturerWin::Stop() {
   running_.store(false, std::memory_order_relaxed);
   secure_desktop_capture_active_.store(false, std::memory_order_relaxed);
+  post_secure_desktop_waiting_for_frame_.store(false,
+                                               std::memory_order_relaxed);
+  post_secure_desktop_drop_logged_.store(false, std::memory_order_relaxed);
+  post_secure_desktop_started_tick_.store(0, std::memory_order_relaxed);
   int ret = 0;
   if (impl_) {
     ret = impl_->Stop();
@@ -626,6 +661,93 @@ void ScreenCapturerWin::StopSecureCaptureThread() {
   }
 }
 
+bool ScreenCapturerWin::RestartCaptureBackendAfterSecureDesktop() {
+  if (!impl_ || !running_.load(std::memory_order_relaxed)) {
+    return false;
+  }
+
+  const bool show_cursor = show_cursor_.load(std::memory_order_relaxed);
+  const int current_monitor = monitor_index_.load(std::memory_order_relaxed);
+  auto restore_monitor = [&]() {
+    RebuildAliasesFromImpl();
+    if (current_monitor > 0 && impl_->SwitchTo(current_monitor) != 0) {
+      monitor_index_.store(0, std::memory_order_relaxed);
+    }
+  };
+  auto try_started_backend = [&](std::unique_ptr<ScreenCapturer> cand,
+                                 const char* name,
+                                 bool is_wgc_plugin) -> bool {
+    if (!cand) {
+      return false;
+    }
+    const int init_ret = cand->Init(fps_, cb_);
+    if (init_ret != 0) {
+      LOG_WARN("Windows capturer: {} init after secure desktop failed (ret={})",
+               name, init_ret);
+      return false;
+    }
+    const int start_ret = cand->Start(show_cursor);
+    if (start_ret != 0) {
+      LOG_WARN(
+          "Windows capturer: {} start after secure desktop failed (ret={})",
+          name, start_ret);
+      cand->Destroy();
+      return false;
+    }
+    if (impl_) {
+      impl_->Destroy();
+    }
+    impl_ = std::move(cand);
+    impl_is_wgc_plugin_ = is_wgc_plugin;
+    restore_monitor();
+    LOG_INFO("Windows capturer: restarted {} after secure desktop", name);
+    return true;
+  };
+
+  LOG_INFO("Windows capturer: restarting capture backend after secure desktop");
+  impl_->Stop();
+  int ret = impl_->Start(show_cursor);
+  if (ret == 0) {
+    restore_monitor();
+    return true;
+  }
+
+  LOG_WARN(
+      "Windows capturer: capture backend restart after secure desktop failed "
+      "(ret={}), rebuilding backend",
+      ret);
+  impl_->Destroy();
+  ret = impl_->Init(fps_, cb_);
+  if (ret == 0) {
+    ret = impl_->Start(show_cursor);
+  }
+  if (ret == 0) {
+    restore_monitor();
+    return true;
+  }
+
+  if (impl_is_wgc_plugin_ &&
+      try_started_backend(WgcPluginCapturer::Create(), "WGC plugin", true)) {
+    return true;
+  }
+  if (try_started_backend(std::make_unique<ScreenCapturerDxgi>(), "DXGI",
+                          false)) {
+    return true;
+  }
+  if (try_started_backend(std::make_unique<ScreenCapturerGdi>(), "GDI",
+                          false)) {
+    return true;
+  }
+
+  if (impl_) {
+    LOG_WARN(
+        "Windows capturer: all backend restart attempts after secure desktop "
+        "failed (last_ret={})",
+        ret);
+  }
+  return false;
+}
+
 bool ScreenCapturerWin::GetCurrentCaptureRegion(int* left, int* top, int* width,
                                                 int* height,
                                                 std::string* display_name) {
@@ -900,6 +1022,9 @@ void ScreenCapturerWin::SecureDesktopCaptureLoop() {
   std::string last_stage;
   std::string last_service_error;
   ULONGLONG capture_stage_started_tick = 0;
+  bool post_secure_restart_pending = false;
+  ULONGLONG post_secure_restart_deadline_tick = 0;
+  ULONGLONG last_post_secure_restart_tick = 0;
   SecureDesktopServiceStatus status;
   std::vector<uint8_t> secure_frame;
 
@@ -951,6 +1076,10 @@ void ScreenCapturerWin::SecureDesktopCaptureLoop() {
                                            std::memory_order_relaxed);
       if (status.capture_active != last_capture_active ||
           status.interactive_stage != last_stage) {
+        const bool secure_capture_started =
+            !last_capture_active && status.capture_active;
+        const bool secure_capture_ended =
+            last_capture_active && !status.capture_active;
         capture_stage_started_tick = now;
         LOG_INFO(
             "Windows capturer secure desktop state: active={}, stage='{}', "
@@ -959,12 +1088,46 @@ void ScreenCapturerWin::SecureDesktopCaptureLoop() {
             status.active_session_id);
         last_capture_active = status.capture_active;
         last_stage = status.interactive_stage;
+        if (secure_capture_started) {
+          post_secure_restart_pending = false;
+          post_secure_desktop_waiting_for_frame_.store(
+              false, std::memory_order_relaxed);
+          post_secure_desktop_drop_logged_.store(
+              false, std::memory_order_relaxed);
+          post_secure_desktop_started_tick_.store(
+              0, std::memory_order_relaxed);
+        } else if (secure_capture_ended) {
+          post_secure_restart_pending = true;
+          post_secure_restart_deadline_tick =
+              now + kPostSecureDesktopRestartTimeoutMs;
+          last_post_secure_restart_tick = 0;
+          post_secure_desktop_waiting_for_frame_.store(
+              true, std::memory_order_relaxed);
+          post_secure_desktop_drop_logged_.store(
+              false, std::memory_order_relaxed);
+          post_secure_desktop_started_tick_.store(
+              now, std::memory_order_relaxed);
+        }
       }
       last_status_tick = now;
     }
 
     if (!status.capture_active || status.active_session_id == 0xFFFFFFFF) {
       StopSecureDesktopSharedCapture(secure_shared_session_id_);
+      if (post_secure_restart_pending) {
+        if (now >= post_secure_restart_deadline_tick) {
+          LOG_WARN(
+              "Windows capturer: capture backend restart after secure desktop "
+              "timed out");
+          post_secure_restart_pending = false;
+        } else if (last_post_secure_restart_tick == 0 ||
+                   now - last_post_secure_restart_tick >=
+                       kPostSecureDesktopRestartRetryMs) {
+          last_post_secure_restart_tick = now;
+          post_secure_restart_pending =
+              !RestartCaptureBackendAfterSecureDesktop();
+        }
+      }
       std::this_thread::sleep_for(
           std::chrono::milliseconds(status.service_available ? 50 : 200));
       continue;

src/screen_capturer/windows/screen_capturer_win.h

@@ -59,6 +59,9 @@ class ScreenCapturerWin : public ScreenCapturer {
   std::atomic<int> monitor_index_{0};
   int initial_monitor_index_ = 0;
   std::atomic<bool> secure_desktop_capture_active_{false};
+  std::atomic<bool> post_secure_desktop_waiting_for_frame_{false};
+  std::atomic<bool> post_secure_desktop_drop_logged_{false};
+  std::atomic<ULONGLONG> post_secure_desktop_started_tick_{0};
   std::thread secure_capture_thread_;
   HANDLE secure_frame_mapping_ = nullptr;
   HANDLE secure_frame_ready_event_ = nullptr;
@@ -77,6 +80,7 @@ class ScreenCapturerWin : public ScreenCapturer {
   void BuildCanonicalFromImpl();
   void RebuildAliasesFromImpl();
   void StopSecureCaptureThread();
+  bool RestartCaptureBackendAfterSecureDesktop();
   void SecureDesktopCaptureLoop();
   bool GetCurrentCaptureRegion(int* left, int* top, int* width, int* height,
                                std::string* display_name);

src/screen_capturer/windows/wgc_session_impl.cpp

@@ -2,23 +2,10 @@
 
 #include <Windows.Graphics.Capture.Interop.h>
 
-#include <atomic>
+#include <string>
-#include <functional>
-#include <memory>
 
 #include "rd_log.h"
 
-#define CHECK_INIT             \
-  if (!is_initialized_) {      \
-    LOG_ERROR("AE_NEED_INIT"); \
-    return 4;                  \
-  }
-
-#define CHECK_CLOSED                         \
-  if (cleaned_.load() == true) {             \
-    throw winrt::hresult_error(RO_E_CLOSED); \
-  }
-
 namespace crossdesk {
 
 extern "C" {
@@ -40,7 +27,7 @@ int WgcSessionImpl::Initialize(HWND hwnd) {
 
   target_.hwnd = hwnd;
   target_.is_window = true;
-  return Initialize();
+  return InitializeLocked();
 }
 
 int WgcSessionImpl::Initialize(HMONITOR hmonitor) {
@@ -48,7 +35,7 @@ int WgcSessionImpl::Initialize(HMONITOR hmonitor) {
 
   target_.hmonitor = hmonitor;
   target_.is_window = false;
-  return Initialize();
+  return InitializeLocked();
 }
 
 void WgcSessionImpl::RegisterObserver(wgc_session_observer* observer) {
@@ -59,68 +46,13 @@ void WgcSessionImpl::RegisterObserver(wgc_session_observer* observer) {
 int WgcSessionImpl::Start(bool show_cursor) {
   std::lock_guard locker(lock_);
 
-  if (is_running_) return 0;
+  return StartLocked(show_cursor);
-
-  int error = 1;
-
-  CHECK_INIT;
-  try {
-    last_show_cursor_ = show_cursor;
-    if (!capture_session_) {
-      auto current_size = capture_item_.Size();
-      capture_framepool_ =
-          winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool::
-              CreateFreeThreaded(d3d11_direct_device_,
-                                 winrt::Windows::Graphics::DirectX::
-                                     DirectXPixelFormat::B8G8R8A8UIntNormalized,
-                                 2, current_size);
-      capture_session_ = capture_framepool_.CreateCaptureSession(capture_item_);
-      capture_frame_size_ = current_size;
-      capture_framepool_trigger_ = capture_framepool_.FrameArrived(
-          winrt::auto_revoke, {this, &WgcSessionImpl::OnFrame});
-      capture_close_trigger_ = capture_item_.Closed(
-          winrt::auto_revoke, {this, &WgcSessionImpl::OnClosed});
-    }
-
-    if (!capture_framepool_) throw std::exception();
-
-    is_running_ = true;
-
-    // we do not need to crate a thread to enter a message loop coz we use
-    // CreateFreeThreaded instead of Create to create a capture frame pool,
-    // we need to test the performance later
-    // loop_ = std::thread(std::bind(&WgcSessionImpl::message_func, this));
-
-    capture_session_.IsCursorCaptureEnabled(show_cursor);
-    capture_session_.StartCapture();
-
-    error = 0;
-  } catch (winrt::hresult_error) {
-    LOG_ERROR("AE_WGC_CREATE_CAPTURER_FAILED");
-    return 86;
-  } catch (...) {
-    return 86;
-  }
-
-  return error;
 }
 
 int WgcSessionImpl::Stop() {
   std::lock_guard locker(lock_);
 
-  CHECK_INIT;
+  CleanUpLocked();
-
-  is_running_ = false;
-
-  // if (loop_.joinable()) loop_.join();
-
-  if (capture_framepool_trigger_) capture_framepool_trigger_.revoke();
-
-  if (capture_session_) {
-    capture_session_.Close();
-    capture_session_ = nullptr;
-  }
-
   return 0;
 }
 
@@ -129,7 +61,10 @@ int WgcSessionImpl::Pause() {
 
   is_paused_ = true;
 
-  CHECK_INIT;
+  if (!is_initialized_) {
+    LOG_ERROR("AE_NEED_INIT");
+    return 4;
+  }
   return 0;
 }
 
@@ -138,7 +73,10 @@ int WgcSessionImpl::Resume() {
 
   is_paused_ = false;
 
-  CHECK_INIT;
+  if (!is_initialized_) {
+    LOG_ERROR("AE_NEED_INIT");
+    return 4;
+  }
   return 0;
 }
 
@@ -175,10 +113,10 @@ auto WgcSessionImpl::CreateCaptureItemForWindow(HWND hwnd) {
       winrt::Windows::Graphics::Capture::GraphicsCaptureItem>();
   auto interop_factory = activation_factory.as<IGraphicsCaptureItemInterop>();
   winrt::Windows::Graphics::Capture::GraphicsCaptureItem item = {nullptr};
-  interop_factory->CreateForWindow(
+  winrt::check_hresult(interop_factory->CreateForWindow(
       hwnd,
       winrt::guid_of<ABI::Windows::Graphics::Capture::IGraphicsCaptureItem>(),
-      reinterpret_cast<void**>(winrt::put_abi(item)));
+      reinterpret_cast<void**>(winrt::put_abi(item))));
   return item;
 }
 
@@ -187,10 +125,10 @@ auto WgcSessionImpl::CreateCaptureItemForMonitor(HMONITOR hmonitor) {
       winrt::Windows::Graphics::Capture::GraphicsCaptureItem>();
   auto interop_factory = activation_factory.as<IGraphicsCaptureItemInterop>();
   winrt::Windows::Graphics::Capture::GraphicsCaptureItem item = {nullptr};
-  interop_factory->CreateForMonitor(
+  winrt::check_hresult(interop_factory->CreateForMonitor(
       hmonitor,
       winrt::guid_of<ABI::Windows::Graphics::Capture::IGraphicsCaptureItem>(),
-      reinterpret_cast<void**>(winrt::put_abi(item)));
+      reinterpret_cast<void**>(winrt::put_abi(item))));
   return item;
 }
 
@@ -218,6 +156,104 @@ HRESULT WgcSessionImpl::CreateMappedTexture(
                                     d3d11_texture_mapped_.put());
 }
 
+int WgcSessionImpl::StartCaptureLocked(bool show_cursor) {
+  if (!is_initialized_) {
+    LOG_ERROR("AE_NEED_INIT");
+    return 4;
+  }
+  if (!capture_item_) {
+    LOG_ERROR("WGC: capture item is null");
+    return 4;
+  }
+
+  try {
+    if (!capture_session_) {
+      auto current_size = capture_item_.Size();
+      capture_framepool_ =
+          winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool::
+              CreateFreeThreaded(d3d11_direct_device_,
+                                 winrt::Windows::Graphics::DirectX::
+                                     DirectXPixelFormat::B8G8R8A8UIntNormalized,
+                                 2, current_size);
+      capture_session_ = capture_framepool_.CreateCaptureSession(capture_item_);
+      capture_frame_size_ = current_size;
+      capture_framepool_trigger_ = capture_framepool_.FrameArrived(
+          winrt::auto_revoke, {this, &WgcSessionImpl::OnFrame});
+      capture_close_trigger_ = capture_item_.Closed(
+          winrt::auto_revoke, {this, &WgcSessionImpl::OnClosed});
+    }
+
+    if (!capture_framepool_ || !capture_session_) {
+      throw std::exception();
+    }
+
+    capture_session_.IsCursorCaptureEnabled(show_cursor);
+    capture_session_.StartCapture();
+    is_running_ = true;
+    return 0;
+  } catch (const winrt::hresult_error&) {
+    LOG_ERROR("AE_WGC_CREATE_CAPTURER_FAILED");
+    return 86;
+  } catch (...) {
+    LOG_ERROR("AE_WGC_CREATE_CAPTURER_FAILED");
+    return 86;
+  }
+}
+
+int WgcSessionImpl::StartLocked(bool show_cursor) {
+  if (is_running_) return 0;
+
+  last_show_cursor_ = show_cursor;
+  if (!is_initialized_) {
+    const int init_ret = InitializeLocked();
+    if (init_ret != 0) {
+      return init_ret;
+    }
+  }
+
+  int ret = StartCaptureLocked(show_cursor);
+  if (ret == 0) {
+    return 0;
+  }
+
+  LOG_WARN("WGC: start capture failed, rebuilding capture item");
+  CleanUpLocked();
+  ret = InitializeLocked();
+  if (ret != 0) {
+    return ret;
+  }
+  return StartCaptureLocked(show_cursor);
+}
+
+void WgcSessionImpl::StopLocked() {
+  is_running_ = false;
+
+  // if (loop_.joinable()) loop_.join();
+
+  if (capture_framepool_trigger_) capture_framepool_trigger_.revoke();
+  if (capture_close_trigger_) capture_close_trigger_.revoke();
+
+  if (capture_session_) {
+    try {
+      capture_session_.Close();
+    } catch (...) {
+      LOG_WARN("WGC: capture session close failed");
+    }
+    capture_session_ = nullptr;
+  }
+
+  if (capture_framepool_) {
+    try {
+      capture_framepool_.Close();
+    } catch (...) {
+      LOG_WARN("WGC: frame pool close failed");
+    }
+    capture_framepool_ = nullptr;
+  }
+
+  d3d11_texture_mapped_ = nullptr;
+}
+
 void WgcSessionImpl::OnFrame(
     winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool const& sender,
     [[maybe_unused]] winrt::Windows::Foundation::IInspectable const& args) {
@@ -225,7 +261,7 @@ void WgcSessionImpl::OnFrame(
 
   auto is_new_size = false;
 
-  {
+  try {
     auto frame = sender.TryGetNextFrame();
     auto frame_size = frame.ContentSize();
 
@@ -239,60 +275,63 @@ void WgcSessionImpl::OnFrame(
     }
 
     // copy to mapped texture
-    {
+    if (is_paused_) {
-      if (is_paused_) {
+      return;
-        return;
-      }
-
-      auto frame_captured =
-          GetDXGIInterfaceFromObject<ID3D11Texture2D>(frame.Surface());
-
-      if (!d3d11_texture_mapped_ || is_new_size) {
-        HRESULT tex_hr = CreateMappedTexture(frame_captured);
-        if (FAILED(tex_hr)) {
-          OutputDebugStringW(
-              (L"CreateMappedTexture failed: " + std::to_wstring(tex_hr))
-                  .c_str());
-          return;
-        }
-      }
-
-      d3d11_device_context_->CopyResource(d3d11_texture_mapped_.get(),
-                                          frame_captured.get());
-
-      D3D11_MAPPED_SUBRESOURCE map_result;
-      HRESULT hr = d3d11_device_context_->Map(
-          d3d11_texture_mapped_.get(), 0, D3D11_MAP_READ,
-          0 /*coz we use CreateFreeThreaded, so we cant use flags
-               D3D11_MAP_FLAG_DO_NOT_WAIT*/
-          ,
-          &map_result);
-      if (FAILED(hr)) {
-        OutputDebugStringW(
-            (L"map resource failed: " + std::to_wstring(hr)).c_str());
-        return;
-      }
-
-      // copy data from map_result.pData
-      if (map_result.pData && observer_) {
-        observer_->OnFrame(
-            wgc_session_frame{static_cast<unsigned int>(frame_size.Width),
-                              static_cast<unsigned int>(frame_size.Height),
-                              map_result.RowPitch,
-                              const_cast<const unsigned char*>(
-                                  (unsigned char*)map_result.pData)},
-            id_);
-      }
-
-      d3d11_device_context_->Unmap(d3d11_texture_mapped_.get(), 0);
     }
-  }
 
-  if (is_new_size) {
+    auto frame_captured =
-    capture_framepool_.Recreate(d3d11_direct_device_,
+        GetDXGIInterfaceFromObject<ID3D11Texture2D>(frame.Surface());
-                                winrt::Windows::Graphics::DirectX::
+
-                                    DirectXPixelFormat::B8G8R8A8UIntNormalized,
+    if (!d3d11_texture_mapped_ || is_new_size) {
-                                2, capture_frame_size_);
+      HRESULT tex_hr = CreateMappedTexture(frame_captured);
+      if (FAILED(tex_hr)) {
+        OutputDebugStringW(
+            (L"CreateMappedTexture failed: " + std::to_wstring(tex_hr))
+                .c_str());
+        return;
+      }
+    }
+
+    d3d11_device_context_->CopyResource(d3d11_texture_mapped_.get(),
+                                        frame_captured.get());
+
+    D3D11_MAPPED_SUBRESOURCE map_result;
+    HRESULT hr = d3d11_device_context_->Map(
+        d3d11_texture_mapped_.get(), 0, D3D11_MAP_READ,
+        0 /*coz we use CreateFreeThreaded, so we cant use flags
+             D3D11_MAP_FLAG_DO_NOT_WAIT*/
+        ,
+        &map_result);
+    if (FAILED(hr)) {
+      OutputDebugStringW(
+          (L"map resource failed: " + std::to_wstring(hr)).c_str());
+      return;
+    }
+
+    // copy data from map_result.pData
+    if (map_result.pData && observer_) {
+      observer_->OnFrame(
+          wgc_session_frame{static_cast<unsigned int>(frame_size.Width),
+                            static_cast<unsigned int>(frame_size.Height),
+                            map_result.RowPitch,
+                            const_cast<const unsigned char*>(
+                                (unsigned char*)map_result.pData)},
+          id_);
+    }
+
+    d3d11_device_context_->Unmap(d3d11_texture_mapped_.get(), 0);
+
+    if (is_new_size) {
+      capture_framepool_.Recreate(
+          d3d11_direct_device_,
+          winrt::Windows::Graphics::DirectX::
+              DirectXPixelFormat::B8G8R8A8UIntNormalized,
+          2, capture_frame_size_);
+    }
+  } catch (const winrt::hresult_error&) {
+    LOG_WARN("WGC: frame processing failed");
+  } catch (...) {
+    LOG_WARN("WGC: frame processing failed");
   }
 }
 
@@ -300,11 +339,13 @@ void WgcSessionImpl::OnClosed(
     winrt::Windows::Graphics::Capture::GraphicsCaptureItem const&,
     winrt::Windows::Foundation::IInspectable const&) {
   std::lock_guard locker(lock_);
+  const bool was_running = is_running_;
+  const bool was_paused = is_paused_;
   try {
-    CleanUp();
+    CleanUpLocked();
-    is_initialized_ = false;
+    is_paused_ = was_paused;
-    if (Initialize() == 0) {
+    if (InitializeLocked() == 0) {
-      int ret = Start(last_show_cursor_);
+      int ret = was_running ? StartCaptureLocked(last_show_cursor_) : 0;
       if (ret == 0) {
         OutputDebugStringW(L"WgcSessionImpl::OnClosed: auto recovered");
       } else {
@@ -319,9 +360,14 @@ void WgcSessionImpl::OnClosed(
   }
 }
 
-int WgcSessionImpl::Initialize() {
+int WgcSessionImpl::InitializeLocked() {
   if (is_initialized_) return 0;
 
+  d3d11_texture_mapped_ = nullptr;
+  d3d11_device_context_ = nullptr;
+  d3d11_direct_device_ = nullptr;
+  capture_frame_size_ = {};
+
   if (!(d3d11_direct_device_ = CreateD3D11Device())) {
     LOG_ERROR("AE_D3D_CREATE_DEVICE_FAILED");
     return 1;
@@ -332,6 +378,10 @@ int WgcSessionImpl::Initialize() {
       capture_item_ = CreateCaptureItemForWindow(target_.hwnd);
     else
       capture_item_ = CreateCaptureItemForMonitor(target_.hmonitor);
+    if (!capture_item_) {
+      LOG_ERROR("WGC: create capture item returned null");
+      return 86;
+    }
 
     // Set up
     auto d3d11_device =
@@ -353,21 +403,18 @@ int WgcSessionImpl::Initialize() {
 void WgcSessionImpl::CleanUp() {
   std::lock_guard locker(lock_);
 
-  auto expected = false;
+  CleanUpLocked();
-  if (cleaned_.compare_exchange_strong(expected, true)) {
+}
-    capture_close_trigger_.revoke();
-    capture_framepool_trigger_.revoke();
 
-    if (capture_framepool_) capture_framepool_.Close();
+void WgcSessionImpl::CleanUpLocked() {
+  StopLocked();
 
-    if (capture_session_) capture_session_.Close();
+  capture_item_ = nullptr;
-
+  d3d11_device_context_ = nullptr;
-    capture_framepool_ = nullptr;
+  d3d11_direct_device_ = nullptr;
-    capture_session_ = nullptr;
+  capture_frame_size_ = {};
-    capture_item_ = nullptr;
+  is_initialized_ = false;
-
+  is_paused_ = false;
-    is_initialized_ = false;
-  }
 }
 
 LRESULT CALLBACK WindowProc(HWND window, UINT message, WPARAM w_param,

src/screen_capturer/windows/wgc_session_impl.h

@@ -68,8 +68,12 @@ class WgcSessionImpl : public WgcSession {
   void OnClosed(winrt::Windows::Graphics::Capture::GraphicsCaptureItem const&,
                 winrt::Windows::Foundation::IInspectable const&);
 
-  int Initialize();
+  int InitializeLocked();
+  int StartLocked(bool show_cursor);
+  int StartCaptureLocked(bool show_cursor);
+  void StopLocked();
   void CleanUp();
+  void CleanUpLocked();
 
   // void message_func();
 
@@ -94,7 +98,6 @@ class WgcSessionImpl : public WgcSession {
   winrt::com_ptr<ID3D11DeviceContext> d3d11_device_context_{nullptr};
   winrt::com_ptr<ID3D11Texture2D> d3d11_texture_mapped_{nullptr};
 
-  std::atomic<bool> cleaned_ = false;
   winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool
       capture_framepool_{nullptr};
   winrt::Windows::Graphics::Capture::Direct3D11CaptureFramePool::