Why would any application well designed open thousands of ports individually rather than a range? Sounds like an unreasonable use case.
I also don't get your point about concurrency. You don't seem to have addressed the point I brought up that opening or closing ports concurrently today already presents undefined behavior. gustavo @ http://niemeyer.net On Aug 6, 2014 2:53 PM, "roger peppe" <roger.pe...@canonical.com> wrote: > On 6 August 2014 10:32, Gustavo Niemeyer <gust...@niemeyer.net> wrote: > > How many port ranges are typically made available? One.. Two? Sounds > like a > > trivial problem. > > Some applications might open thousands of individual ports. > It would be nice if it worked well in that case too. > > > In terms of concurrency, there are issues either way. Someone can open a > > port while it is being closed, and whether that works or not depends > purely > > on timing. > > When we've got several units sharing a port space, we'll want to > keep a unique owner for each port range. That's trivial if the > reference can be keyed by the port range, but not > as straightforward if the lookup is two-phase. > > What we don't want is two units in the same machine to be > able to have the same port open at the same time. I suppose > we could rely on the fact that hooks do not execute simultaneously, > but it would be preferable in my view to keep those > concerns separate. > > In my view, "always close the range you've opened" is an easy > to explain rule, and makes quite a few things simpler, > without being overly restrictive. > > > gustavo @ http://niemeyer.net > > > > On Aug 6, 2014 9:41 AM, "roger peppe" <roger.pe...@canonical.com> wrote: > >> > >> On 5 August 2014 19:34, Gustavo Niemeyer <gust...@niemeyer.net> wrote: > >> > On Tue, Aug 5, 2014 at 4:18 PM, roger peppe <rogpe...@gmail.com> > wrote: > >> >> close ports 80-110 -> error (mismatched port range?) > >> > > >> > I'd expect ports to be closed here, and also on 0-65536. > >> > >> I'm not sure. An advantage of requiring that exactly the > >> same ports must be closed as were opened, you can use the port range > >> as a key, which makes for a very simple (and trivially concurrent-safe) > >> implementation in a mongo collection. > >> > >> I'd suggest that this compromise is worth it. We could always make an > >> initial > >> special case for 0-65535 too, if desired. >
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