initial commit, 4.5 stable

thirdparty/embree/common/sys/ref.h

@@ -0,0 +1,122 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "atomic.h"
+
+namespace embree
+{
+  struct NullTy {
+  };
+
+  extern MAYBE_UNUSED NullTy null;
+  
+  class RefCount
+  {
+  public:
+    RefCount(int val = 0) : refCounter(val) {}
+    virtual ~RefCount() {};
+  
+    virtual RefCount* refInc() { refCounter.fetch_add(1); return this; }
+    virtual void refDec() { if (refCounter.fetch_add(-1) == 1) delete this; }
+  private:
+    std::atomic<size_t> refCounter;
+  };
+  
+  ////////////////////////////////////////////////////////////////////////////////
+  /// Reference to single object
+  ////////////////////////////////////////////////////////////////////////////////
+
+  template<typename Type>
+  class Ref
+  {
+  public:
+    Type* ptr;
+
+    ////////////////////////////////////////////////////////////////////////////////
+    /// Constructors, Assignment & Cast Operators
+    ////////////////////////////////////////////////////////////////////////////////
+
+    __forceinline Ref() : ptr(nullptr) {}
+    __forceinline Ref(NullTy) : ptr(nullptr) {}
+    __forceinline Ref(const Ref& input) : ptr(input.ptr) { if (ptr) ptr->refInc(); }
+    __forceinline Ref(Ref&& input) : ptr(input.ptr) { input.ptr = nullptr; }
+
+    __forceinline Ref(Type* const input) : ptr(input)
+    {
+      if (ptr)
+        ptr->refInc();
+    }
+
+    __forceinline ~Ref()
+    {
+      if (ptr)
+        ptr->refDec();
+    }
+
+    __forceinline Ref& operator =(const Ref& input)
+    {
+      if (input.ptr)
+        input.ptr->refInc();
+      if (ptr)
+        ptr->refDec();
+      ptr = input.ptr;
+      return *this;
+    }
+
+    __forceinline Ref& operator =(Ref&& input)
+    {
+      if (ptr)
+        ptr->refDec();
+      ptr = input.ptr;
+      input.ptr = nullptr;
+      return *this;
+    }
+
+    __forceinline Ref& operator =(Type* const input)
+    {
+      if (input)
+        input->refInc();
+      if (ptr)
+        ptr->refDec();
+      ptr = input;
+      return *this;
+    }
+
+    __forceinline Ref& operator =(NullTy)
+    {
+      if (ptr)
+        ptr->refDec();
+      ptr = nullptr;
+      return *this;
+    }
+
+    __forceinline operator bool() const { return ptr != nullptr; }
+
+    __forceinline const Type& operator  *() const { return *ptr; }
+    __forceinline       Type& operator  *()       { return *ptr; }
+    __forceinline const Type* operator ->() const { return  ptr; }
+    __forceinline       Type* operator ->()       { return  ptr; }
+
+    template<typename TypeOut>
+    __forceinline       Ref<TypeOut> cast()       { return Ref<TypeOut>(static_cast<TypeOut*>(ptr)); }
+    template<typename TypeOut>
+    __forceinline const Ref<TypeOut> cast() const { return Ref<TypeOut>(static_cast<TypeOut*>(ptr)); }
+
+    template<typename TypeOut>
+    __forceinline       Ref<TypeOut> dynamicCast()       { return Ref<TypeOut>(dynamic_cast<TypeOut*>(ptr)); }
+    template<typename TypeOut>
+    __forceinline const Ref<TypeOut> dynamicCast() const { return Ref<TypeOut>(dynamic_cast<TypeOut*>(ptr)); }
+  };
+
+  template<typename Type> __forceinline bool operator < (const Ref<Type>& a, const Ref<Type>& b) { return a.ptr   <  b.ptr;   }
+
+  template<typename Type> __forceinline bool operator ==(const Ref<Type>& a, NullTy            ) { return a.ptr   == nullptr; }
+  template<typename Type> __forceinline bool operator ==(NullTy            , const Ref<Type>& b) { return nullptr == b.ptr;   }
+  template<typename Type> __forceinline bool operator ==(const Ref<Type>& a, const Ref<Type>& b) { return a.ptr   == b.ptr;   }
+
+  template<typename Type> __forceinline bool operator !=(const Ref<Type>& a, NullTy            ) { return a.ptr   != nullptr; }
+  template<typename Type> __forceinline bool operator !=(NullTy            , const Ref<Type>& b) { return nullptr != b.ptr;   }
+  template<typename Type> __forceinline bool operator !=(const Ref<Type>& a, const Ref<Type>& b) { return a.ptr   != b.ptr;   }
+}