Re: Longjumps considered inexpensive...until they aren't

2008-06-21 Thread Charles Oliver Nutter
Charles Oliver Nutter wrote: > This is a longer post, but very important for JRuby. > > In John Rose's post on using flow-control exceptions for e.g. nonlocal > returns, he showed that when the throw and catch are close enough > together (i.e. same JIT compilation unit) HotSpot can turn them int

Re: Time to reconsider m:n or green threading options?

2008-06-21 Thread Charles Oliver Nutter
Patrick Wright wrote: > Looks like the original threading model in the Sun JVM was 1:n threading > > http://en.wikipedia.org/wiki/Green_threads That fits my memory as well. > Most of what I found on a quick Google seemed to confirm that article. > Apparently "green threads", as implemented earli

Re: Time to reconsider m:n or green threading options?

2008-06-21 Thread Patrick Wright
Looks like the original threading model in the Sun JVM was 1:n threading http://en.wikipedia.org/wiki/Green_threads Most of what I found on a quick Google seemed to confirm that article. Apparently "green threads", as implemented earlier in the Sun JVMs, had one OS thread, running the VM, which w

Time to reconsider m:n or green threading options?

2008-06-21 Thread Charles Oliver Nutter
Seems to me lately all the super-scaling languages and runtimes getting attention are based on m:n or green threads across multiple processes. Given that kernel threads obviously can't scale up to the tens of thousands of concurrent processes e.g. Erlang can handle, is it possibly a good time t

A sudden concern about invokedynamic

2008-06-21 Thread Charles Oliver Nutter
It occurred to me just now there could be a small snag with invokedynamic. Maybe it's addressed in the spec, but I don't have it here right now. If it's not a problem, a 5-second explanation would do. Otherwise, we might want to discuss here, since it's certainly multi-language related. How wo