AK: Fixes for atomic pointers

AK/Atomic.h

@@ -46,6 +46,18 @@ static inline T atomic_exchange(volatile T* var, T desired, MemoryOrder order =
     return __atomic_exchange_n(var, desired, order);
 }
 
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline V* atomic_exchange(volatile T** var, V* desired, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_exchange_n(var, desired, order);
+}
+
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline V* atomic_exchange(volatile T** var, std::nullptr_t, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_exchange_n(const_cast<V**>(var), nullptr, order);
+}
+
 template<typename T>
 static inline bool atomic_compare_exchange_strong(volatile T* var, T& expected, T desired, MemoryOrder order = memory_order_seq_cst) noexcept
 {
@@ -55,6 +67,25 @@ static inline bool atomic_compare_exchange_strong(volatile T* var, T& expected,
         return __atomic_compare_exchange_n(var, &expected, desired, false, order, order);
 }
 
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline bool atomic_compare_exchange_strong(volatile T** var, V*& expected, V* desired, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    if (order == memory_order_acq_rel || order == memory_order_release)
+        return __atomic_compare_exchange_n(var, &expected, desired, false, memory_order_release, memory_order_acquire);
+    else
+        return __atomic_compare_exchange_n(var, &expected, desired, false, order, order);
+}
+
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline bool atomic_compare_exchange_strong(volatile T** var, V*& expected, std::nullptr_t, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    if (order == memory_order_acq_rel || order == memory_order_release)
+        return __atomic_compare_exchange_n(const_cast<V**>(var), &expected, nullptr, false, memory_order_release, memory_order_acquire);
+    else
+        return __atomic_compare_exchange_n(const_cast<V**>(var), &expected, nullptr, false, order, order);
+}
+
+
 template<typename T>
 static inline T atomic_fetch_add(volatile T* var, T val, MemoryOrder order = memory_order_seq_cst) noexcept
 {
@@ -91,12 +122,30 @@ static inline T atomic_load(volatile T* var, MemoryOrder order = memory_order_se
     return __atomic_load_n(var, order);
 }
 
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline V* atomic_load(volatile T** var, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_load_n(const_cast<V**>(var), order);
+}
+
 template<typename T>
 static inline void atomic_store(volatile T* var, T desired, MemoryOrder order = memory_order_seq_cst) noexcept
 {
     __atomic_store_n(var, desired, order);
 }
 
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline void atomic_store(volatile T** var, V* desired, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    __atomic_store_n(var, desired, order);
+}
+
+template<typename T, typename V = typename RemoveVolatile<T>::Type>
+static inline void atomic_store(volatile T** var, std::nullptr_t, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    __atomic_store_n(const_cast<V**>(var), nullptr, order);
+}
+
 template<typename T>
 class Atomic {
     T m_value { 0 };
@@ -111,7 +160,7 @@ public:
     {
     }
 
-    volatile T* ptr()
+    volatile T* ptr() noexcept
     {
         return &m_value;
     }
@@ -240,7 +289,7 @@ public:
     {
     }
 
-    volatile T** ptr()
+    volatile T** ptr() noexcept
     {
         return &m_value;
     }