Initial commit

arm9/source/core/SharedPtr.h

@@ -0,0 +1,163 @@
+#pragma once
+
+static inline u32 arm_getCpsr()
+{
+    u32 cpsr;
+    asm volatile("mrs %0, cpsr" : "=r" (cpsr));
+    return cpsr;
+}
+
+static inline void arm_setCpsrControl(u32 cpsrControl)
+{
+    asm volatile("msr cpsr_c, %0" :: "r" (cpsrControl) : "cc");
+}
+
+static inline u32 arm_disableIrqs(void)
+{
+    u32 oldCpsr = arm_getCpsr();
+    arm_setCpsrControl(oldCpsr | 0x80);
+    return oldCpsr;
+}
+
+static inline void arm_restoreIrqs(u32 oldCpsr)
+{
+    arm_setCpsrControl(oldCpsr);
+}
+
+template <class T>
+class SharedPtr
+{
+    T* _pointer;
+    vu32* _refCount;
+
+public:
+    SharedPtr()
+        : _pointer(nullptr), _refCount(nullptr) { (void)sizeof(T); }
+
+    explicit SharedPtr(T* pointer)
+        : _pointer(pointer), _refCount(pointer ? new u32(1) : nullptr) { (void)sizeof(T); }
+
+    SharedPtr(const SharedPtr& other)
+    {
+        u32 irq = arm_disableIrqs();
+        _pointer = other._pointer;
+        _refCount = other._refCount;
+        if (_pointer)
+        {
+            (*_refCount)++;
+        }
+        arm_restoreIrqs(irq);
+    }
+
+    SharedPtr(SharedPtr&& other)
+        : _pointer(other._pointer), _refCount(other._refCount)
+    {
+        other._pointer = nullptr;
+        other._refCount = nullptr;
+    }
+
+    ~SharedPtr()
+    {
+        Reset();
+    }
+
+    [[gnu::noinline]]
+    SharedPtr& operator=(const SharedPtr& other)
+    {
+        u32 irq = arm_disableIrqs();
+        T* pointer = _pointer;
+        if (pointer)
+        {
+            vu32* refCount = _refCount;
+            u32 newValue = *refCount - 1;
+            *refCount = newValue;
+            _pointer = other._pointer;
+            _refCount = other._refCount;
+            if (_pointer)
+            {
+                (*_refCount)++;
+            }
+            arm_restoreIrqs(irq);
+            if (newValue == 0)
+            {
+                delete pointer;
+                delete refCount;
+            }
+        }
+        else
+        {
+            _pointer = other._pointer;
+            _refCount = other._refCount;
+            if (_pointer)
+            {
+                (*_refCount)++;
+            }
+            arm_restoreIrqs(irq);
+        }
+        return *this;
+    }
+
+    [[gnu::noinline]]
+    SharedPtr& operator=(SharedPtr&& other)
+    {
+        u32 irq = arm_disableIrqs();
+        T* pointer = _pointer;
+        if (pointer)
+        {
+            vu32* refCount = _refCount;
+            u32 newValue = *refCount - 1;
+            *refCount = newValue;
+            _pointer = other._pointer;
+            _refCount = other._refCount;
+            other._pointer = nullptr;
+            other._refCount = nullptr;
+            arm_restoreIrqs(irq);
+            if (newValue == 0)
+            {
+                delete pointer;
+                delete refCount;
+            }
+        }
+        else
+        {
+            _pointer = other._pointer;
+            _refCount = other._refCount;
+            other._pointer = nullptr;
+            other._refCount = nullptr;
+            arm_restoreIrqs(irq);
+        }
+        return *this;
+    }
+
+    [[gnu::noinline]]
+    void Reset()
+    {
+        u32 irq = arm_disableIrqs();
+        T* pointer = _pointer;
+        if (pointer)
+        {
+            vu32* refCount = _refCount;
+            u32 newValue = *refCount - 1;
+            *refCount = newValue;
+            _pointer = nullptr;
+            _refCount = nullptr;
+            arm_restoreIrqs(irq);
+            if (newValue == 0)
+            {
+                delete pointer;
+                delete refCount;
+            }
+        }
+        else
+        {
+            arm_restoreIrqs(irq);
+        }
+    }
+
+    constexpr T& operator*() const { return *_pointer; }
+    constexpr T* operator->() const { return _pointer; }
+
+    constexpr T* GetPointer() const { return _pointer; }
+    constexpr u32 GetRefCount() const { return _refCount ? *_refCount : 0; }
+    constexpr bool IsValid() const { return _pointer; }
+};