It's a matter of point of view, but to me cooperative/preemptive is a property of the underlying scheduler, not of what the programmer is usually exposed to. As you correctly pointed out, it is possible to block the scheduler with uncooperative code. It's not even hard: it takes just one heavy CPU-bound computation. I write these kind of computations every day: if you sell me a system as preemptive and it's not, I will get angry...
It's a matter of point of view, but to me cooperative/preemptive is a property of the underlying scheduler, not of what the programmer is usually exposed to. As you correctly pointed out, it is possible to block the scheduler with uncooperative code. It's not even hard: it takes just one heavy CPU-bound computation. I write these kind of computations every day: if you sell me a system as preemptive and it's not, I will get angry...