Re:The ancient world before computers had stacks or heaps
by sgerenser on Thursday April 04, 2024 @06:56AM
(#39928722)
Pretty sure even with virtual memory (which was actually added sometime in the System 7 days), you still could manually set the minimum and desired memory sizes for each app. Maybe it made less of a difference than it used to, but I still remember tweaking those values for certain apps (like trying to open a large file in Photoshop) even after MacOS 8 and 9 were out. MacOS X was a breath of fresh air by comparison.
Re:The ancient world before computers had stacks or heaps
by shadowgovt on Thursday April 04, 2024 @11:43AM
(#39931852)
You definitely could. I can't remember right now what effect that had, because the whole thing was running atop a virtual memory layer at that point... I can't recall if it was a lie (i.e. feature existed but had no effect) or if it had some effect on how long it'd be before an app started resorting to paging out RAM pages.
The system allocated the heap (and libraries, I think) at the bottom and the stack at the top of that physical-RAM slice, and off you went.
I believe around system 8 they added a virtualization layer that started to obviate the need for that approach (and of course by the time of MacOSX they were using paged memory like everyone else was and so such fancy tap-dancing was no longer needed). But it's fun to think about the era where this "one weird trick" from Art of Computer Programming was how we allocated RAM for multiple concurrent applications.