Atom: Swift's actor implementation for .NET / Unity

Runtime/Threading/Atom.cs  ​

(c) 2026 Sator Imaging, Licensed under the MIT License https://github.com/sator-imaging/Unity-Fundamentals

Basic Usage

var atom = new Atom<int>();

atom.Set = 310;
atom.Update = v => ++v;  // Increments (311)

atom.Set = 42;
atom.Read = v => Console.WriteLine(v);  // Prints 42

atom.WriteLock((x: 42, y: "Tuple"), static (args, current) =>
{
    return current + args.x + args.y.Length;
});

If T is reference type, the object properties can be modified in read lock context.

var atom = new Atom<MyClass>(value: new());

atom.ReadLock(foo, static (foo, myClass) =>
{
    // NOTE: Lock is taken until the operation finished.
    //       (e.g., For a second, other thread cannot access to the atom value at all)
    System.Threading.Thread.Sleep(1000);

    myClass.Data = foo.Value;
});