Why One Frozen App Doesn’t Take Down Your Whole PC
Why can you keep typing when another app stops responding? The operating system can interrupt the stuck app, save its place and give something else a turn.
TIMESTAMPS:
00:00 One app is stuck. You can still type.
01:26 How the timer takes control
03:01 Save the place and the value
05:34 What if we forget the saved value?
06:25 Waiting, ready and running
08:59 An earlier response, the same work
10:03 What more cores change
10:52 Why the stuck app stays stuck
11:46 One last interruption test
Episode 7 of How Computers Work, From Scratch. No programming experience required.
Related lesson — What happens when a computer sees Python?
• What happens when a computer sees Python?
Primary references:
Operating Systems: Three Easy Pieces — Limited Direct Execution
https://pages.cs.wisc.edu/~remzi/OSTEP/cpu...
Microsoft — Context Switches
https://learn.microsoft.com/en-us/windows/...
Microsoft — About Processes and Threads
https://learn.microsoft.com/en-us/windows/...
The windows, addresses and scheduling timelines are simplified illustrations. The example does not claim that every frozen window is a busy loop, or that real operating systems always use equal turns.