Add new VideoConference module for muting mic/cam (#11798)

* add new VideoConference module for muting mic/cam

Co-authored-by: PrzemyslawTusinski <61138537+PrzemyslawTusinski@users.noreply.github.com>
Co-authored-by: Niels Laute <niels.laute@live.nl>

src/modules/videoconference/VideoConferenceShared/SerializedSharedMemory.h

@@ -0,0 +1,54 @@
+#pragma once
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+
+#include <Windows.h>
+#include <string>
+#include <optional>
+#include <wil/resource.h>
+#include <functional>
+#include <array>
+
+// Wrapper class allowing sharing readonly/writable memory with a serialized access via atomic locking.
+// Note that it doesn't protect against a 3rd party concurrently modifying physical file contents.
+class SerializedSharedMemory
+{
+public:
+    struct memory_t
+    {
+      uint8_t * _data = nullptr;
+      size_t _size = 0;
+    };
+
+    static std::optional<SerializedSharedMemory> create(const std::wstring_view object_name,
+                                                        const size_t size,
+                                                        const bool read_only,
+                                                        SECURITY_ATTRIBUTES* maybe_attributes = nullptr) noexcept;
+    static std::optional<SerializedSharedMemory> create_readonly(
+        const std::wstring_view object_name,
+        const std::wstring_view file_path,
+        SECURITY_ATTRIBUTES* maybe_attributes = nullptr) noexcept;
+    static std::optional<SerializedSharedMemory> open(const std::wstring_view object_name,
+                                                      const size_t size,
+                                                      const bool read_only) noexcept;
+
+    void access(std::function<void(memory_t)> access_routine) noexcept;
+    inline size_t size() const noexcept { return _memory._size; }
+
+    ~SerializedSharedMemory() noexcept;
+    SerializedSharedMemory(SerializedSharedMemory&&) noexcept;
+    SerializedSharedMemory& operator=(SerializedSharedMemory&&) noexcept;
+
+private:
+    std::array<wil::unique_handle, 2> _handles;
+    memory_t _memory;
+    bool _read_only = true;
+    constexpr static inline int64_t LOCKED = 1;
+
+    char* lock_flag_addr() noexcept;
+    void lock() noexcept;
+    void unlock() noexcept;
+
+    SerializedSharedMemory(std::array<wil::unique_handle, 2> handles, memory_t memory, const bool readonly) noexcept;
+};