site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com In message <4472D0D3.8000002@teaching.physics.ox.ac.uk>, Graham J Lee writes:

I think the argument would be that system startup is just a specific example of the general case "something interesting happened and I want to be run because of it", and that launchd deals with the happening of interesting things. I'd agree with that, if it were the argument :-)

Hmm. Well, that suggests a way to resolve this fairly elegantly; just provide a hook in plists for having services Do Something which causes other services to run. So, say, you add a tag like <key>StartupDone</key> <string>Gzornenplatzen</string> in some plists, and in others, you have <key>StartupAfter</key> <string>Gzornenplatzen</string> Bam. Nice generic way to put the "something happened and I want to be run" *IN LAUNCHD WHERE IT BELONGS* rather than having all the applications sit around inventing new notification methods and writing their own code. That's the thing; in many cases, it's utterly trivial to explain what ordering I want. If I have an ordering tool, I need one or two lines of code somewhere. If I have to do all the arbitration by hand, I can end up doing callbacks and daemon communications in two or three different protocols at once. Which goes against the idea of a unified launcher which hides this complexity.

As a sysadmin, launchd's allowed me to consolidate a mess of crontabs, inetd/xinetd configurations, watchdog configurations[1], StartupItems and custom rc.local files into a mess of plists looked at by just two tools[2]. Still speaking as a sysadmin I tend to think of programs that aren't launchd-ready as being so last century (what with there probably being an order of magnitude more Tiger users than any other Unix distribution, apart from maybe panther) and in need of some updating.

Some programs can be trivially updated, although in practice, I'd bet that nearly nothing is completely "launchd-ready" in terms of surviving edge conditions ("I put /Applications on a USB disk that takes a minute to power up").

Of course, my dev hat reminds me how much work that can involve...

Yeah. -s _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... This email sent to site_archiver@lists.apple.com