Watchdog

From AwkwardTV
Revision as of 23:09, 18 August 2007 by XqvBvg (talk | contribs)
Jump to: navigation, search

leccami www mls com zafferano bicchieri zoran jelenkovic tv studio pctv ati fire incanto classic saeco risultati motomondiale 2004 km0 mitsubishi pajero sport auto km 0 schede madri asus p4p800s sigma 12-24 sn una tettona cittadinanza canon lbp 2000 toner microfono ps2 chi ha vinto piu coppe al mondo calcio dinotopia tablet pc 12 1 hp manifesto ringraziamenti fiat coupe 1 8 turbo nh hotel chacker soho square erikson e la crisi psico sociale gioco all aperto bambino minolta toner cuffie wireless dolby digital il libro della aldo giovanni e giacomo volo aereo palermo lampedusa iraq fotos ivy queen loona bailando pulitore vapore smallville kristin kreuk nuda fax 3310l prestito bruxelles bepi koelliker regali per casa dpr 686 del 3 5 1957 yety sport 5 rrufeja toyota mantova velodyne vx10 camera villorba www canzoni di leone di lernia it foto camera digitale online olimpia splendid deumidificatore batterie samsung e800 ecco i cieli del mito libri casper slide la macchina nera kingston ddr sodimm fromage frais invernali ninne nanne in italiano esce il drago entra la tigre peretta volkswagen fox diesel dori ghezzi wess cantautore garmin gps iii seks vidoe corpi vogliamoci tanto bene lalbero delle pere the biggest black cock un grande amore picrite star wars. clone wars. vol. 01 jogos da playboy nike calcio ecco la demo di age of empires iii la camera della morte terratec aureon universe 7 1 dvd-rw 9 4 gb internet a passo di lumaca piastra per bistecchiera piscina di antegnate appendici carrelli www lady web it guri quarta serie speciale 13 dicembre 2 hub 5 porte ethernet rod usted de diego torres olivetti logos 682 s piatti in vetro trottolino hp 200 todo lo que hago lo hago por ti sale marino integrale testo voglia di dance all night kit cp 100 film erotici helena figo sexy orbs athlon 64 939 3000 pieces de rechange processori intel pentium 4 prescott foto naziskin tocuh santo antonio pisa san francisco biglietti aerei gamepad pc saitek tarantelle pugliesi breezin gamepad joystick hotel centrale jesolo fotos garotas nuas navigatore gps blaupunkt grimaudo piastre intercambiabili cranberries zombi chat gay roma gratis bey usb sharp gx30 extremo mina in studio audi a3 1.6 calciatore nudo lampade risparmio energetico handel cd logitech premium usb headset 350 kuman mi manchi pooh dvd 8x princo yonis musica per i tuoi sogni pirandello l esclusa piscine montichiari rex rd 185 dx wwwpetardas con cardim, fernao set lettino bando straordinario 19 12 2005 servizio civile silke www google ro europa grecia isola ibm t43 foto di pantere www robertobaggio it zorro alla corte di spagna drow wavelenght schema fattura infradito sandali dichiarazione dei rediti sia di fornaci frankfurt an der oder fz 61 1 primi denunciati tu soltanto tu delta v via da qui mp3 preromanticismo il pingpong arctic cooling nv silencer 5 heroin labtec mouse optical big girls www canzoni da scaricare it grandmaster flash belle di notre dame de paris ocktoberfest un emozione da poco anna oxa love lina modem 56 interno xp crimsom rooom dvd rip numer barzallette cattive colin mcrea rally 2 classiche napoletane byblos terra stampante epson stylus pro 4000 chu mei andrews virginia libri fliston fortuna slim bluetooth la canzone dei vecchi amanti photos colocataires m6 ef 100 macro grow2 kaoma video lambada a scuola dallo sciamano harrrdito duello nel ventre della terra samira saeed aspirapolvere 1400 notebook toshiba libretto u100 la tani free sheet music everybody is changing cafe1930 telefonia fissa essenza si zegna romani acer dlp adobe acrobat 6 0 professional sunstech dvp sound blaster zs notebook ===What is Watchdog===

Watchdog is a service monitoring daemon responsible for rebooting the Apple TV if its GUI application is not running. Its main goal is to reboot the system if the Finder application fails to launch and stay running for a period of time (58 seconds, as far as I can tell). It keeps track of the number of times it's rebooted the system due to a hung or crashed Finder, and when this happens a certain number of times in a row (5 times I believe) it performs some action -- presumably restoring to factory defaults, or to the last known good state.

There's a kext called AppleTCOWatchdog.kext in the /System/Library/Extensions/ folder.

Brief Watchdog Background

Watchdog is a service monitoring daemon that has its roots in Apple's server OS, Mac OS X Server. Watchdog monitors and, as required, relaunches critical processes on the machine. When hardware such as Apple's server hardware, Xserve is present, watchdog is even able to reboot the machine if the power management hardware fails to respond.

This should not be confused with the "watchdog" program from OS X 10.3 and earlier -- it is unrelated, and we should probably delete all of the references to it on this page. :/

The Ripstop Daemon

Ripstop is a background system daemon launched by the launchd process in its role as the successor to mach_init. Ripstop opens a communications channel with the Watchdog service within the kernel, and keeps a notification port open to allow other processes to 'ping' the watchdog, and perform some other duties.

Ripstop Details

Ripstop responds to six notifications, all sent via the low-level notify_post() application:

  • com.apple.riptide.heartbeat
  • com.apple.riptide.start
  • com.apple.riptide.stop
  • com.apple.ripstop.query
  • com.apple.ripstop.debug

The Finder application actually sets up a timer which fires every 58 seconds to make the following call:

notify_post( "com.apple.riptide.heartbeat" );

This is essentially the 'keepalive' notification used to inform the watchdog that everything is hunky-dory.

Upon launch, ripstop switches to the Frontrow user