Comment by Timwi

In operating systems, we call that cooperative multitasking (everything up to DOS+Windows 3.11, where software is allowed to hog the CPU until it explicitly yields) versus preemptive multitasking (Windows 95 onwards, where software is regularly interrupted by the OS). There's a reason preemptive multitasking has “won” and nobody wants to go back to cooperative. A lot of software just isn't cooperative (i.e. doesn't yield enough).