1 files changed, 45 insertions, 0 deletions
diff --git a/std/atomic/stack.zig b/std/atomic/stack.zig
new file mode 100644
index 0000000000..4ceecb7b1d
--- /dev/null
+++ b/std/atomic/stack.zig
@@ -0,0 +1,45 @@
+/// Many reader, many writer, non-allocating, thread-safe, lock-free
+pub fn Stack(comptime T: type) type {
+    return struct {
+        root: ?&Node,
+
+        pub const Self = this;
+
+        pub const Node = struct {
+            next: ?&Node,
+            data: T,
+        };
+
+        pub fn init() Self {
+            return Self {
+                .root = null,
+            };
+        }
+
+        /// push operation, but only if you are the first item in the stack. if you did not succeed in
+        /// being the first item in the stack, returns the other item that was there.
+        pub fn pushFirst(self: &Self, node: &Node) ?&Node {
+            node.next = null;
+            return @cmpxchgStrong(?&Node, &self.root, null, node, AtomicOrder.AcqRel, AtomicOrder.AcqRel);
+        }
+
+        pub fn push(self: &Self, node: &Node) void {
+            var root = @atomicLoad(?&Node, &self.root, AtomicOrder.Acquire);
+            while (true) {
+                node.next = root;
+                root = @cmpxchgWeak(?&Node, &self.root, root, node, AtomicOrder.Release, AtomicOrder.Acquire) ?? break;
+            }
+        }
+
+        pub fn pop(self: &Self) ?&Node {
+            var root = @atomicLoad(?&Node, &self.root, AtomicOrder.Acquire);
+            while (true) {
+                root = @cmpxchgWeak(?&Node, &self.root, root, (root ?? return null).next, AtomicOrder.Release, AtomicOrder.Acquire) ?? return root;
+            }
+        }
+
+        pub fn isEmpty(self: &Self) bool {
+            return @atomicLoad(?&Node, &self.root, AtomicOrder.Relaxed) == null;
+        }
+    };
+}