[darcs-users] Automatic darcs

[Samuel A. Falvo II]

On Thursday 05 August 2004 11:46 pm, Martin Pool wrote:
> The Microsoft documentation says otherwise: there is a fixed-size
> buffer.  If it overflows, information is lost.
>
> (Please don't suggest that we just hope nobody's files are lost.)

Hmm...I must have misread the information then.  Or maybe confusing it 
with OS/2's.

I do know AmigaOS 2.x and later has a feature that supports this.  Just 
one more reason AmigaOS is better than Linux.  >:)

> 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.

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.

> Implementing #2 is possible but you get a risk of priority inversion
> or deadlock between the OS and the application.

This was not an issue in AmigaOS, by design.

--
Samuel A. Falvo II