Swift

I loved Swift 6.4's new withTaskCancellationShield, until I saw it only works on the 27 OSes. So I dug into why, and built a way to use it on earlier versions.

How do you tell a DNS proxy extension that its 250k-domain blocklist changed? Not with `NotificationCenter` — that stops at the process boundary. Darwin notifications, `notifyd`, C callbacks, and why "system-wide" cuts both ways.

I finally read SE-0306 and actors stopped being a mystery. Here's everything that clicked, in plain language.

Actors let tasks slip through reentrancy and a Mutex can't be held across an await — so how do you guarantee an async method never runs twice at once? A line-by-line look at how Matt Massicotte's TaskGate pulls it off.

I wrapped a delegate-based SDK in async/await because it was "modern." Then I realized I had just bolted a Tesla engine onto a horse carriage.