Switching std::thread to XThread and hosting in object_refs.

src/xenia/kernel/xobject.h

@@ -24,6 +24,9 @@ namespace kernel {
 
 class KernelState;
 
+template <typename T>
+class object_ref;
+
 // http://www.nirsoft.net/kernel_struct/vista/DISPATCHER_HEADER.html
 typedef struct {
   xe::be<uint32_t> type_flags;
@@ -99,6 +102,124 @@ class XObject {
   std::string name_;  // May be zero length.
 };
 
+template <typename T>
+class object_ref {
+ public:
+  object_ref() noexcept : value_(nullptr) {}
+  object_ref(nullptr_t) noexcept : value_(nullptr) {}
+  object_ref& operator=(nullptr_t) noexcept {
+    reset();
+    return (*this);
+  }
+
+  explicit object_ref(T* value) noexcept : value_(value) {
+    // Assumes retained on call.
+  }
+  explicit object_ref(const object_ref& right) noexcept {
+    reset(right.get());
+    if (value_) value_->Retain();
+  }
+  template <class V, class = typename std::enable_if<
+                         std::is_convertible<V*, T*>::value, void>::type>
+  object_ref(const object_ref<V>& right) noexcept {
+    reset(right.get());
+    if (value_) value_->Retain();
+  }
+
+  object_ref(object_ref&& right) noexcept : value_(right.release()) {}
+  object_ref& operator=(object_ref&& right) noexcept {
+    object_ref(std::move(right)).swap(*this);
+    return (*this);
+  }
+  template <typename V>
+  object_ref& operator=(object_ref<V>&& right) noexcept {
+    object_ref(std::move(right)).swap(*this);
+    return (*this);
+  }
+
+  object_ref& operator=(const object_ref& right) noexcept {
+    object_ref(right).swap(*this);
+    return (*this);
+  }
+  template <typename V>
+  object_ref& operator=(const object_ref<V>& right) noexcept {
+    object_ref(right).swap(*this);
+    return (*this);
+  }
+
+  void swap(object_ref& right) noexcept {
+    std::_Swap_adl(value_, right.value_);
+  }
+
+  ~object_ref() noexcept {
+    if (value_) {
+      value_->Release();
+      value_ = nullptr;
+    }
+  }
+
+  typename std::add_lvalue_reference<T>::type operator*() const {
+    return (*get());
+  }
+
+  T* operator->() const noexcept {
+    return std::pointer_traits<T*>::pointer_to(**this);
+  }
+
+  T* get() const noexcept { return value_; }
+
+  template <typename V>
+  V* get() const noexcept {
+    return reinterpret_cast<V*>(value_);
+  }
+
+  explicit operator bool() const noexcept { return value_ != nullptr; }
+
+  T* release() noexcept {
+    T* value = value_;
+    value_ = nullptr;
+    return value;
+  }
+
+  static void accept(T* value) {
+    reset(value);
+    value->Release();
+  }
+
+  void reset() noexcept { object_ref().swap(*this); }
+
+  void reset(T* value) noexcept { object_ref(value).swap(*this); }
+
+ private:
+  T* value_ = nullptr;
+};
+
+template <class _Ty>
+bool operator==(const object_ref<_Ty>& _Left, nullptr_t) noexcept {
+  return (_Left.get() == (_Ty*)0);
+}
+
+template <class _Ty>
+bool operator==(nullptr_t, const object_ref<_Ty>& _Right) noexcept {
+  return ((_Ty*)0 == _Right.get());
+}
+
+template <class _Ty>
+bool operator!=(const object_ref<_Ty>& _Left, nullptr_t _Right) noexcept {
+  return (!(_Left == _Right));
+}
+
+template <class _Ty>
+bool operator!=(nullptr_t _Left, const object_ref<_Ty>& _Right) noexcept {
+  return (!(_Left == _Right));
+}
+
+template <typename T>
+object_ref<T> retain_object(T* ptr) {
+  if (ptr) ptr->Retain();
+  return object_ref<T>(ptr);
+}
+
 }  // namespace kernel
 }  // namespace xe