Creating a state machine in Swift Nov 13 2019

State machines are used to model systems that can be thought of as a collection of states, and a collection of events that cause state changes. Many of the systems we want to model can be abstracted to a state machine. For example, elements in a Game...

Making a C library available in Swift using the Swift Package Manager Nov 7 2019

System libraries are typically defined using C, that means we need a way to make them available to Swift. In this post, we are going to explore how to use the Swift Package Manager to give us access to C libraries, be it system or user-defined.

Let...

Multithreading with pthreads in Swift Oct 29 2019

Long gone are the days when single process single thread was the norm. We now take multithreading for granted, we expect all our applications not to lockup when we interact with them. We expect them to handle multiple users at the same time, etcetera...

Creating a Launch Agent that provides an XPC service on macOS using Swift Oct 21 2019

Last week we discussed how to build XPC Services(the .xpc bundles) inside your macOS applications. This week we are going to explore how to provide XPC services that can be used from other applications or tools.

To make the XPC service available to...

XPC Services on macOS apps using Swift Oct 17 2019

We have access to many Inter-Process-Communication(IPC) mechanisms in macOS. One of the newest is XPC¹. Before XPC a common way to use IPC, and provide services between processes, was through Sockets or Mach Messages (Using Mach Ports).

Nowadays,...

Using Kernel Queues (kqueue) notifications in Swift Oct 9 2019

Many components of macOS trace their roots back to BSD. One key aspect inherited from BSD is the Kernel Event Notification mechanism know as Kernel Queues (kqueues for short).

In the past, before kqueue(2)¹/ kevent(2)², when we wanted to track events...

Understanding the RunLoop model by creating a basic shell Oct 1 2019

When we find ourselves listening for events, reacting to those events, and then going back to listening for more events, we have ourselves an Event-Loop. Having an event-loop is a common scenario. So common that Apple decided to provide us with a model...

Using BSD Sockets in Swift Sep 24 2019

Apple provides many useful network frameworks. Network.framework (you can check my previous article on Network.framework if you want to see an example) is the latest. But sometimes we need to go deeper, and the abstractions might get in the way. In...

Understanding Objective-C and Swift interoperability Sep 16 2019

There are many reasons to use more than one programming language in a project. In some cases, a lot of work has gone into building a framework (years maybe). Rewriting the whole framework to have the codebase in the same programming language, might...

Building a server-client application using Apple's Network Framework Sep 10 2019

Apple's network APIs are many, the older APIs are well documented, and you'll find lots of examples. Not so much about the new Network framework. One factor might be that the name is not that search-friendly. In this post, I'll explain how to use the...

Understanding a few concepts of macOS applications by building an agent-based (menu bar) app Sep 3 2019

With advances in the frameworks and tools we use to develop software, creating a new app seems like magic. We just click a few buttons, and everything is created for us. I enjoy magic, but I think that sometimes we end up being Framework "users" without...

My Xcode gitignore template Aug 28 2019

I would like to change the template Xcode uses to generate a git repository, but I haven't found how. So at the moment when I want to use my .gitignore template I just pull it from a GIST.

This y my Xcode .gitignore template. I use the raw address...