ACE on FreeBSD?

[Julian Elischer]

Julian Elischer wrote:
> Bruce M. Simpson wrote:
>> Hi,
>>
>> I looked at ACE years and years ago (~1997) when Doug Schmidt was 
>> first promoting the ideas behind it. The whole Reactor/Proactor split 
>> pretty much hangs on the event dispatch which your particular OS 
>> supports.
>>
>> The key observation is whether your target OS implements events in an 
>> edge-triggered or level-triggered way; I am borrowing definitions from 
>> electronic engineering here.
>>
>> You could do a straight port with Proactor, but performance will 
>> probably suck, because both FreeBSD (and Linux, I believe) need to 
>> emulate POSIX asynchronous I/O operations.
>>
>> Reactor will generally "fare better" on UNIX derived systems such as 
>> FreeBSD and Linux, because its event handling primitives are geared 
>> towards the level-triggered facilities provided by select().
> 
> A true FreeBSD port would use kevent with AIO.
> At Cisco/ironport we use AIO with the build in kevent trigering to
> great effect. Certainly for sockets it works VERY well.

sorry I meant for sockets and raw devices.. (what we use them for)
sockets don't need AIO to work well with kevent but raw devices do.
Luckily it works as advertised.


> 
>>
>> In Windows, Winsock events use asynchronous notifications which may be 
>> tied to Win32 EVENT objects, and the usual Kernel32.DLL thread 
>> primitives are used around this. This makes Proactor more appropriate 
>> in that environment.
>>
>> XORP does some similar stuff to ACE under the hood to support the 
>> native socket facilities of both Windows and FreeBSD/Linux. It's 
>> hybridized but it behaves more like Reactor because we run in a single 
>> thread, and you have to force Winsock's helper thread to run, by 
>> preempting you, using some file handle and socket tricks.
>>
>> I don't currently know about stability of ACE on FreeBSD.
>>
>> cheers
>> BMS
>> _______________________________________________
>> freebsd-net at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-net
>> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
> 
> _______________________________________________
> freebsd-net at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"