From 93b9832faced7dc816ca1a9f3552488fc35037d1 Mon Sep 17 00:00:00 2001
From: Tom <tomut@yahoo.com>
Date: Mon, 1 Jun 2020 22:55:30 -0600
Subject: [PATCH] AK: Add atomic free functions

This allows for using atomic operations on any variables,
not only those wrapped in AK::Atomic<T>
---
 AK/Atomic.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/AK/Atomic.h b/AK/Atomic.h
index f06eca1203c67d..b9edb817fa0bfa 100644
--- a/AK/Atomic.h
+++ b/AK/Atomic.h
@@ -39,6 +39,63 @@ enum MemoryOrder {
     memory_order_seq_cst = __ATOMIC_SEQ_CST
 };
 
+template <typename T>
+static inline T atomic_exchange(volatile T* var, T desired, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_exchange_n(var, desired, 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
+{
+    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>
+static inline T atomic_fetch_add(volatile T* var, T val, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_fetch_add(var, val, order);
+}
+
+template <typename T>
+static inline T atomic_fetch_sub(volatile T* var, T val, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_fetch_sub(var, val, order);
+}
+
+template <typename T>
+static inline T atomic_fetch_and(volatile T* var, T val, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_fetch_and(var, val, order);
+}
+
+template <typename T>
+static inline T atomic_fetch_or(volatile T* var, T val, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_fetch_or(var, val, order);
+}
+
+template <typename T>
+static inline T atomic_fetch_xor(volatile T* var, T val, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_fetch_xor(var, val, order);
+}
+
+template <typename T>
+static inline T atomic_load(volatile T* var, MemoryOrder order = memory_order_seq_cst) noexcept
+{
+    return __atomic_load_n(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>
 class Atomic {
     T m_value { 0 };
@@ -53,6 +110,11 @@ class Atomic {
     {
     }
 
+    volatile T* ptr()
+    {
+        return &m_value;
+    }
+
     T exchange(T desired, MemoryOrder order = memory_order_seq_cst) volatile noexcept
     {
         return __atomic_exchange_n(&m_value, desired, order);
@@ -177,6 +239,11 @@ class Atomic<T*> {
     {
     }
 
+    volatile T** ptr()
+    {
+        return &m_value;
+    }
+
     T* exchange(T* desired, MemoryOrder order = memory_order_seq_cst) volatile noexcept
     {
         return __atomic_exchange_n(&m_value, desired, order);