Detailed exploration of how RunningBoard manages the service updating data for a widget, and how that update is scheduled and run by chronod.
scheduling
Since the update to XProtect Remediator version 151, many have seen warnings of a plugin being cancelled. This explains how that happens, and what you can do about it.
How DAS gathers its budgets and loads lists of activities. When rescoring permits, it then dispatches the process to initiate backup. Re-scheduling has changed in Sequoia, as shown here.
Easy to code, these don’t need to use XPC although it’s used by the DAS-CTS scheduling and dispatch system. They aren’t run at constant time intervals, but when appropriate according to other loads.
How does XProtect Remediator scan your Mac once a day? What has gone wrong when it doesn’t appear to work? Explained from its property lists to its three different types of scan.
There’s normally more than 500 background activities, like Time Machine backups and XProtect Remediator scans, waiting for dispatch in the list maintained by DAS. How this works.
Since 2005, macOS has had the master launcher launchd and its LaunchAgents and LaunchDaemons. Then in 2014 Apple added Duet Activity Scheduler to run tasks when conditions are suitable.
Code run in a lightweight Virtual Machine can’t take advantage of the Efficiency cores of the host Apple silicon Mac. How then does Sonoma handle its threads?
While macOS uses DAS-CTS to schedule hundreds of background activities, third-parties normally use launchd. Comes with a full diagram explaining DAS-CTS.
How running a background task takes a tiny fraction of second, although the task itself takes seconds or minutes, and why it’s run on E cores.
The Eclectic Light Company 