Cannot compile on Windows 7 64 bits with Visual Studio 2013 community.

[Hal Murray]

> With a little work (a simple enough job that I don't need to be the one to
> do it, I think) it should be possible to change the --disable-dns-lookup
> option to always use synchronous lookup on hostnames, so the IP-only
> restriction is removed at the cost of a small amount of startup lag.

I think you are confusing things by thinking of it as a startup problem.

The pool stuff also does DNS lookups and those may happen at non-startup time.

Even if startup works, I'd like to be able to occasionally (say daily) use 
DNS to verify that the server is still in the pool.  That's a long-term 
project.  Something like that would also be useful to verify that a 
(non-pool) server hadn't moved.

I agree that it's worth investigating using synchronous DNS.  I expect it 
will work fine on a lightly loaded system which covers most of the systems 
running ntpd.

On the other hand, I think we should be able to make a clean threaded 
version.  Don't get fooled by the current code.  It's not an inherently hard 
problem.  A good example might be useful for other projects.


> Later, after I deliver replay, I'm going to do a bunch of profiling. I'm not
> actually convinced that the async-dns code is worth its complexity cost in
> avoided startup lag, and I mean to measure the difference over a large
> number of runs to find out. 

I think that will be misleading on several counts.

The question is not what is the average time, but rather what is the worst 
case.

The performance in your environment may not tell you much about my 
environment.

-- 
These are my opinions.  I hate spam.