Re: Communication between applications

[Richard Frith-Macdonald]

On Thursday, October 10, 2002, at 02:24  pm, Yen-Ju Chen wrote:

>  Thanx.
>  I will use the NSDistributedNotificationCenter.
>  I just wonder how expensive the NSDistributedNotificationCenter
>  is in comparison to the NSNotificationCenter ?

Extremely!
NSNotificationCentre gives you a highly optimised in-memory lookup
executing entirely in user space.
NSDistributedNotificationCentre involves sending messages through
the networking stack in kernel space to the gdnc process, and from
there via the same mechanism to the receiving process ... it's
probably in the region of three orders of magnitude slower.

>  For example, about 10 notification per second and
>  last about 3-5 seconds (when user drag the NSSlider).

I'd guess that's ok ... but best try it and see.  Any mechanism
for IPC is going to be quite slow - but I'd try simple solutions
before worrying about optimising.