README

We prefer to work with immutable types in functional-programming. However, it's not always possible, and sometimes we need some shared mutable state. With the immutable types in this library you'd need to protect the updates with locks:

// Some global
HashSet<int> set = HashSet(1, 2, 3);
object sync = new();

lock(sync)
{
    set = set.Add(4);
}

This in unsatisfactory, and so this module is all about lock-free atomic operations. Atom allows you to protect any value. AtomHashMap and AtomSeq are HashMap and Seq wrapped up into a lock-free mutable structure. Snapshots of those are free! The above code can be written:

AtomHashSet<int> set = AtomHashSet(1, 2, 3);
set.Add(4);

Finally, there's the Software Transactional Memory (STM) system. Which allows for transactional changes to multiple Ref values. Ref just wrap up access to a value, and allows the state changes to be tracked by the STM.

See the concurrency section of the wiki for more info.