> MacOS prior to X was cooperatively scheduled across the whole OS, and it was definitely breaking down and why Apple needed such a radical change.
Preemptive multitasking was definitely one of the headline features of Mac OS X, but I think the other major one—protected memory—was the more important problem to solve with classic MacOS. Performance on classic MacOS was better for many common workloads than OS X, for several versions of the latter. And yes, playing a video while minimizing the window was a cool demo, and that capability is table stakes for an OS now. But the crashing bomb app demo was far more compelling for most of us Mac greybeards.
That said, cooperative concurrency in JS is a very different thing than in an OS. It’s not a panacea of course, but the typical APIs available are pervasively concurrent or trivial to make concurrent. And where that’s not enough (CPU bound workloads), all mainstream JS environments now support real threads. Granted that doesn’t mean JS is an ideal solution for CPU bound workloads… but if JS is already a prerequisite, it’s worth considering scaling out with threads before more expensive process spawning and IPC.
Preemptive multitasking was definitely one of the headline features of Mac OS X, but I think the other major one—protected memory—was the more important problem to solve with classic MacOS. Performance on classic MacOS was better for many common workloads than OS X, for several versions of the latter. And yes, playing a video while minimizing the window was a cool demo, and that capability is table stakes for an OS now. But the crashing bomb app demo was far more compelling for most of us Mac greybeards.
That said, cooperative concurrency in JS is a very different thing than in an OS. It’s not a panacea of course, but the typical APIs available are pervasively concurrent or trivial to make concurrent. And where that’s not enough (CPU bound workloads), all mainstream JS environments now support real threads. Granted that doesn’t mean JS is an ideal solution for CPU bound workloads… but if JS is already a prerequisite, it’s worth considering scaling out with threads before more expensive process spawning and IPC.