In our previous discussion, we explored the intricacies of stateful but coalescing update notifications, shedding light on the pivotal role of the UI thread in implicit serialization. However, what if this luxury of implicit synchronization is absent? Delving into an alternate version of our solution, we confront the looming specter of race conditions and the necessity for meticulous thread management to ensure seamless operation. Join us as we navigate the complexities of thread synchronization and embark on a quest to refine our approach to asynchronous work handling.  

Adding State to the Update Notification Pattern, Part 4

by Raymond Chen

From the article:

Last time, we developed a stateful but coalescing update notification, and we noted that the UI thread was doing a lot of heavy lifting. What if you don’t have a UI thread to do implicit serialization for you?

If there were no resume_foreground(Dispatcher()), we would have a race if a Text­Changed occurs after the worker has decided to exit, but before it has had a chance to mark itself as not busy. Here’s an alternate version that demonstrates the race.