From 3ecd8511f2401d61b512c1f9fad1e6f6eb5676e5 Mon Sep 17 00:00:00 2001
From: Aidan Lee <aidan.lee63@gmail.com>
Date: Fri, 4 Jul 2025 20:01:45 +0100
Subject: [PATCH] emulate atomic object for hxcpp

---
 std/cpp/_std/haxe/atomic/AtomicObject.hx      | 59 +++++++++++++++++++
 std/haxe/atomic/AtomicObject.hx               |  4 +-
 .../unitstd/haxe/atomic/AtomicObject.unit.hx  |  2 +-
 3 files changed, 62 insertions(+), 3 deletions(-)
 create mode 100644 std/cpp/_std/haxe/atomic/AtomicObject.hx

diff --git a/std/cpp/_std/haxe/atomic/AtomicObject.hx b/std/cpp/_std/haxe/atomic/AtomicObject.hx
new file mode 100644
index 00000000000..a8c129d1a6f
--- /dev/null
+++ b/std/cpp/_std/haxe/atomic/AtomicObject.hx
@@ -0,0 +1,59 @@
+package haxe.atomic;
+
+private class AtomicObjectImpl<T> {
+	public final lock : sys.thread.Mutex;
+
+	public var obj : T;
+
+	public function new(obj) {
+		this.lock = new sys.thread.Mutex();
+		this.obj  = obj;
+	}
+}
+
+abstract AtomicObject<T:{}>(AtomicObjectImpl<T>) {
+	public function new(value:T) {
+		this = new AtomicObjectImpl(value);
+	}
+
+	public function compareExchange(expected:T, replacement:T):T {
+		this.lock.acquire();
+		return if (this.obj == expected) {
+			final current = this.obj;
+			this.obj = replacement;
+			this.lock.release();
+
+			current;
+		} else {
+			final current = this.obj;
+			this.lock.release();
+			
+			current;
+		}
+	}
+
+	public function exchange(value:T):T {
+		this.lock.acquire();
+		final current = this.obj;
+		this.obj = value;
+		this.lock.release();
+
+		return current;
+	}
+
+	public function load():T {
+		this.lock.acquire();
+		final current = this.obj;
+		this.lock.release();
+
+		return current;
+	}
+
+	public function store(value:T):T {
+		this.lock.acquire();
+		this.obj = value;
+		this.lock.release();
+
+		return value;
+	}
+}
\ No newline at end of file
diff --git a/std/haxe/atomic/AtomicObject.hx b/std/haxe/atomic/AtomicObject.hx
index 01b959b2480..8c8c051b332 100644
--- a/std/haxe/atomic/AtomicObject.hx
+++ b/std/haxe/atomic/AtomicObject.hx
@@ -4,8 +4,8 @@ package haxe.atomic;
 #error "This target does not support atomic operations."
 #end
 
-#if (js || cpp)
-#error "JavaScript and Hxcpp do not support AtomicObject"
+#if js
+#error "JavaScript does not support AtomicObject"
 #end
 
 /**
diff --git a/tests/unit/src/unitstd/haxe/atomic/AtomicObject.unit.hx b/tests/unit/src/unitstd/haxe/atomic/AtomicObject.unit.hx
index 7f95e195f7f..8b5183e8604 100644
--- a/tests/unit/src/unitstd/haxe/atomic/AtomicObject.unit.hx
+++ b/tests/unit/src/unitstd/haxe/atomic/AtomicObject.unit.hx
@@ -1,4 +1,4 @@
-#if (target.atomics && !(js || cpp))
+#if (target.atomics && !js)
 var a = new haxe.atomic.AtomicObject("Hey World!");
 
 a.load() == "Hey World!";