From 462a4e09b1a67562dd1a122936c1ad0fc1771e0e Mon Sep 17 00:00:00 2001
From: Fabian Imhof <fabian.imhof@ost.ch>
Date: Thu, 27 Feb 2025 07:15:03 +0000
Subject: add smart pointers

---
 arch/x86_64/include/arch/stl/shared_pointer.hpp | 120 ++++++++++++++++++++++++
 arch/x86_64/include/arch/stl/unique_pointer.hpp |  68 ++++++++++++++
 2 files changed, 188 insertions(+)
 create mode 100644 arch/x86_64/include/arch/stl/shared_pointer.hpp
 create mode 100644 arch/x86_64/include/arch/stl/unique_pointer.hpp

diff --git a/arch/x86_64/include/arch/stl/shared_pointer.hpp b/arch/x86_64/include/arch/stl/shared_pointer.hpp
new file mode 100644
index 0000000..79a9f82
--- /dev/null
+++ b/arch/x86_64/include/arch/stl/shared_pointer.hpp
@@ -0,0 +1,120 @@
+#ifndef TEACHOS_ARCH_X86_64_STL_SHARED_POINTER_HPP
+#define TEACHOS_ARCH_X86_64_STL_SHARED_POINTER_HPP
+
+namespace teachos::arch::stl
+{
+  template<typename T>
+  struct shared_pointer
+  {
+    explicit shared_pointer(T * pointer = nullptr)
+        : pointer(pointer)
+        , ref_count(new std::atomic<int>(pointer != nullptr ? 1 : 0))
+    {
+    }
+
+    shared_pointer(const shared_pointer & other)
+        : pointer(other.pointer)
+        , ref_count(other.ref_count)
+    {
+      if (pointer != nullptr)
+      {
+        ++(*ref_count);
+      }
+    }
+
+    shared_pointer(shared_pointer && other) noexcept
+        : pointer(other.pointer)
+        , ref_count(other.ref_count)
+    {
+      other.pointer = nullptr;
+      other.ref_count = nullptr;
+    }
+
+    shared_pointer & operator=(const shared_pointer & other)
+    {
+      if (this != &other)
+      {
+        cleanup();
+        pointer = other.pointer;
+        ref_count = other.ref_count;
+
+        if (pointer != nullptr)
+        {
+          ++(*ref_count);
+        }
+      }
+
+      return *this;
+    }
+
+    shared_pointer & operator=(shared_pointer && other) noexcept
+    {
+      if (this != &other)
+      {
+        cleanup();
+        pointer = other.pointer;
+        ref_count = other.ref_count;
+        other.pointer = nullptr;
+        other.ref_count = nullptr;
+      }
+
+      return *this;
+    }
+
+    ~shared_pointer() { cleanup(); }
+
+    void cleanup()
+    {
+      if (pointer != nullptr && ref_count != nullptr && --(*ref_count) == 0)
+      {
+        delete pointer;
+        delete ref_count;
+      }
+    }
+
+    void reset(T * p = nullptr)
+    {
+      cleanup();
+      pointer = p;
+      ref_count = new std::atomic<int>(p != nullptr ? 1 : 0);
+    }
+
+    void swap(shared_pointer & other)
+    {
+      std::swap(pointer, other.pointer);
+      std::swap(ref_count, other.ref_count);
+    }
+
+    T & operator*() const { return *pointer; }
+
+    T * operator->() const { return pointer; }
+
+    T * get() const { return pointer; }
+
+    int use_count() const
+    {
+      if (pointer != nullptr)
+      {
+        return *ref_count;
+      }
+
+      return 0;
+    }
+
+    bool unique() const { return use_count() == 1; }
+
+    explicit operator bool() const { return pointer != nullptr; }
+
+  private:
+    T * pointer;
+    std::atomic<int> * ref_count;
+  };
+
+  template<typename T, typename... Args>
+  shared_pointer<T> make_shared(Args &&... args)
+  {
+    return shared_pointer<T>(new T(std::forward<Args>(args)...));
+  }
+}  // namespace teachos::arch::stl
+
+#endif  // TEACHOS_ARCH_X86_64_STL_SHARED_POINTER_HPP
\ No newline at end of file
diff --git a/arch/x86_64/include/arch/stl/unique_pointer.hpp b/arch/x86_64/include/arch/stl/unique_pointer.hpp
new file mode 100644
index 0000000..0ec3c38
--- /dev/null
+++ b/arch/x86_64/include/arch/stl/unique_pointer.hpp
@@ -0,0 +1,68 @@
+#ifndef TEACHOS_ARCH_X86_64_STL_UNIQUE_POINTER_HPP
+#define TEACHOS_ARCH_X86_64_STL_UNIQUE_POINTER_HPP
+
+namespace teachos::arch::stl
+{
+  template<typename T>
+  struct unique_pointer
+  {
+    explicit unique_pointer(T * ptr = nullptr)
+        : pointer(ptr)
+    {
+    }
+
+    ~unique_pointer() { delete pointer; }
+
+    unique_pointer(const unique_pointer &) = delete;
+    unique_pointer & operator=(const unique_pointer &) = delete;
+
+    unique_pointer(unique_pointer && other) noexcept
+        : pointer(other.pointer)
+    {
+      other.pointer = nullptr;
+    }
+
+    unique_pointer & operator=(unique_pointer && other) noexcept
+    {
+      if (this != &other)
+      {
+        delete pointer;
+        pointer = other.pointer;
+        other.pointer = nullptr;
+      }
+      return *this;
+    }
+
+    T & operator*() const { return *pointer; }
+
+    T * operator->() const { return pointer; }
+
+    T * get() const { return pointer; }
+
+    T * release()
+    {
+      T * temp = pointer;
+      pointer = nullptr;
+      return temp;
+    }
+
+    void reset(T * ptr = nullptr)
+    {
+      delete pointer;
+      pointer = ptr;
+    }
+
+    void swap(unique_pointer & other) { std::swap(pointer, other.pointer); }
+
+  private:
+    T * pointer;
+  };
+
+  template<typename T, typename... Args>
+  unique_pointer<T> make_unique(Args &&... args)
+  {
+    return unique_pointer<T>(new T(std::forward<Args>(args)...));
+  }
+}  // namespace teachos::arch::stl
+
+#endif  // TEACHOS_ARCH_X86_64_STL_UNIQUE_POINTER_HPP
\ No newline at end of file
-- 
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