[darcs-users] Automatic darcs

Martin Pool mbp at sourcefrog.net
Fri Aug 6 07:36:37 UTC 2004


On  6 Aug 2004, "Samuel A. Falvo II" <sam.falvo at falvotech.com> wrote:

> > 1- Losing information if the file system changes faster than the
> > application can respond.
> >
> > 2- Slowing down the filesystem to a rate that the application can
> > handle.
> 
> AmigaOS implemented option 2, but did not suffer any performance penalty.  
> dos.library would allocate messages and dispatch them to the listening 
> tasks.  Since message sends are asynchronous (just one more reason to 
> avoid asynchronous IPC like the plague!), it just went ahead and 
> performed the operation as appropriate.

I assume by asynchronous you mean that the OS would send the message
and not wait for a reply.  So what happened when it ran out of memory
for messages?

Suppose the application takes two weeks to respond to each
notification.  Does the OS eventually stop IO until the application
responds, or discard messages, or panic?

> Also, AmigaOS is still the only OS I'm aware of that lets applications 
> trap individual file access (e.g., not just changes to a directory, but 
> constraining monitoring to just a single [set of] file[s]).  This also 
> facilitated superior resource consumption rates.

That would be nice.

-- 
Martin 




More information about the darcs-users mailing list