🐛 [Windows] Fix: if an exception is thrown in the constructor make su…

…re we properly cleanup Because the destructor won't get called, but we have already init some of our members and they need to be cleaned up
CoolLibs · Oct 21, 2024 · 0c7af1a · 0c7af1a
1 parent c08cde4
commit 0c7af1a
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Showing 2 changed files with 32 additions and 6 deletions.
diff --git a/src/internal/wcam_windows.cpp b/src/internal/wcam_windows.cpp
@@ -403,10 +403,13 @@ STDMETHODIMP CaptureImpl::BufferCB(double /* time */, BYTE* buffer, long buffer_
     return S_OK;
 }
 
-CaptureImpl::~CaptureImpl()
+MediaControlRAII::~MediaControlRAII()
 {
-    _media_control->Stop();
-    _media_control->Release();
+    if (_media_control)
+    {
+        _media_control->Stop();
+        _media_control->Release();
+    }
 }
 
 static auto get_resolutions(IBaseFilter* capture_filter) -> std::vector<Resolution>

diff --git a/src/internal/wcam_windows.hpp b/src/internal/wcam_windows.hpp
@@ -6,12 +6,35 @@
 
 namespace wcam::internal {
 
+class MediaControlRAII {
+public:
+    MediaControlRAII() = default;
+    ~MediaControlRAII();
+    MediaControlRAII(MediaControlRAII const&)                = delete;
+    MediaControlRAII& operator=(MediaControlRAII const&)     = delete;
+    MediaControlRAII(MediaControlRAII&&) noexcept            = delete;
+    MediaControlRAII& operator=(MediaControlRAII&&) noexcept = delete;
+
+    auto operator->() -> IMediaControl* { return _media_control; }
+    auto operator->() const -> IMediaControl const* { return _media_control; }
+    auto operator*() -> IMediaControl& { return *_media_control; }
+    auto operator*() const -> IMediaControl const& { return *_media_control; }
+    operator IMediaControl*() { return _media_control; } // NOLINT(*explicit*)
+    IMediaControl** operator&()                          // NOLINT(*runtime-operator)
+    {
+        return &_media_control;
+    }
+
+private:
+    IMediaControl* _media_control{};
+};
+
 EXTERN_C const IID IID_ISampleGrabberCB;
 class CaptureImpl : public ISampleGrabberCB
     , public ICaptureImpl {
 public:
     CaptureImpl(DeviceId const& id, Resolution const& resolution);
-    ~CaptureImpl() override;
+    ~CaptureImpl() override                                = default;
     CaptureImpl(CaptureImpl const&)                        = delete;
     auto operator=(CaptureImpl const&) -> CaptureImpl&     = delete;
     CaptureImpl(CaptureImpl&&) noexcept                    = delete;
@@ -32,8 +55,8 @@ class CaptureImpl : public ISampleGrabberCB
     Resolution _resolution{};
     GUID       _video_format{}; // At the moment we support MEDIASUBTYPE_RGB24 and MEDIASUBTYPE_NV12 (which is required for the OBS virtual camera)
 
-    IMediaControl* _media_control{};
-    ULONG          _ref_count{0};
+    MediaControlRAII _media_control{};
+    ULONG            _ref_count{0};
 };
 
 } // namespace wcam::internal