Turns out that the problem isn't concurrency per se, but shared mutable memory that an attacking process can sneak in and rewrite before the kernel reads it - a

Turns out that the problem isn't concurrency per se, but shared mutable memory that an attacking process can sneak in and rewrite before the kernel reads it - and any schoolchild knows that if someone can sneak in and scribble all over something, they will. As if all the other problems with mutable state weren't quite bad enough... :) I wonder how the history of computer architecture would have been altered had someone discovered a memory technology where writing into empty cells was very easy, but altering them extremely difficult, back in 1953? Such a memory technology would have been perfectly utilised by functional programming techniques, but would have made traditional mutable state extremely expensive (not impossible, as monads demonstrate, but not primitive). What would be different today...?