> There reaches a point where threads are much less free than events.
Why?
> Newer concurrency systems will handle thousands or millions of lightweight processes without firing up large numbers of native threads, and there's a reason for that design decision.
I would say that is based on the historically accurate but currently false notion that OS threads are expensive to start up or keep idle.
It's still true -- I recommend looking at some comparisons. Worker-thread based http servers consistently have worse performance at handling a large number of connections, and the error rate for those (simply) using threads is also higher at large number of connections,
Why?
> Newer concurrency systems will handle thousands or millions of lightweight processes without firing up large numbers of native threads, and there's a reason for that design decision.
I would say that is based on the historically accurate but currently false notion that OS threads are expensive to start up or keep idle.