I'm looking for a way to occupy exactly 80% (or any other number) of a single CPU in a consistent manner.
I need this for some unit test that tests a component that triggers under specific CPU utilization conditions
For this purpose I can assume that the machine is otherwise idle.
What's a robust and possibly OS independent way to do this?
There is no such thing as occupying the CPU 80% of the time. The CPU is always either being used, or idle. Over some period of time, you can get average usage to be 80%. Is there a specific time period you want it to be averaged over? This pseudo-code should work across platforms and over 1 second have a CPU usage of 80%:
while True:
startTime = time.now()
while date.now() - startTime < 0.8:
Math.factorial(100) // Or any other computation here
time.sleep(0.2)