Watchdog

From AwkwardTV
Revision as of 07:43, 1 September 2007 by XqvBvg (talk | contribs)
Jump to: navigation, search

libro fantascienza www godo lidia troia basi a chi mi dice patch italiano winmx la sorella max condizionatori wisi y yandel zeroassoluto foto cazzi circoncisi pietre artificiali fotocamera digitali novita cavo firewire 800 campionato calcio olandese outlet opportunita di lavoro verwoerd hendrik frensch www hard muvi tv mercedes 320 e portovenere aspazija comprare solo nike shox weuro bigas luna riforma protestante ann magnuson annunci video gratis vyksa defcon 4 samsung digimax 240 pagine bianche bergamo canzoni wrestling wwe bionda cs cp18 acer notebook 3023wlmi gli spogliati body abbigliamento per neonati benassi bros tip my heart media center john scofield quiet sdram 133mhz v9999gt td v525 motorola cellulari foto di julian mc mahon spot telecom berlusconi dissipatori hd isocronismo ricambi per autoradio www comune bologna it kig kog battere supporto da parete per tv plasma da quando non ci sei luce laser no le temas a el hector y tito trebol clan foto protagoniste grande fratello the clipper foto privata venezuela hp photosmart 2710 allinone audi pavia mc donalds professional regulations commission www alfa romeo com inter 2006 lk dj marky sodimm kingston 256 mb www comune siena it giochi per psx telesilla hp computer workstation uccisione ostaggio iglese mini one d emilia romagna mezcla latina build a cyber baby libero di crepare articolo da pesca mdyankse traccia sistemi 2004 singoli milano psicologia multiculturali gabber mafia jbl diffusori da pavimento ariete elettrodomestico ferro da stiro amstrad cantanti sexi foto gallery amatoriali porno gratis vienna offerta la playa del sol eletti in europa drunk moms cocaina sesso alien shooter altoparlanti creative trigue 5 1 panochas peludas edius ca germinazione e le stelle stanno a guardare veroli alessia marcuzzi nuda integrale pobre diabla por don omar jvc dr mv1se villaggi residence sicilia running a cuneo toner 3715 etnie masterizzatori dvd dual layer server dedicato linux campana dino hp 5 2 program 6 cpr 4098 mg reyna mia cartografia europa www pipoclub com testi canzoni straniere i peni piu lunghi del mondo canon 2350 blowjob relazione esami di licenza media dal nostro inviato a copenaghen magia yamaha tzr dory ghezzi volo economico caraibi doom film comune castelcucco alyssa ashley una donna tra due mondi kaon ktsc 570 incontro per sesso a firenze ati 9250 vivo stadio aqua e sapone foto annuncio singola shemale big cock netgear ps121 bmw pisa hp 450 video de michelle vieth encuerada thomson tv plasma iride hotel scaloppine ariete 420 miserabile fallimento piu ci penso f 80 scarpe donna con tacco alto dvd vergini dvdram rex piano incasso retroescavatori flash digitale tecnologie catch and fish stammheim the servant orchestra testo tradotto liliane singoli bisex superdotati worldsex com carol of the bells blu brondi cordless batteria olympus li12b bomba nucleare decapitazione ostaggio turco hagen krzysztof krawczyk trudno nam sound blaster live 24 bit external milano malpensa timothy pardo y aliaga felipe wifi palmari supporti dvd vergini i racconti dello zio tom lavatrice altezza 50 cm geforce 6600 gt sli schede video www solo mutui it software telefonia marketing alberghiero arkanoid 2d mamen sanz i tre della squadra speciale sotto il sole di satana presheva com taglia tubi red ran tutti tipi di giochi in italiano dvd r vcr benq dc 1300 palm treo 650 albergo 5 stella vienna polti ferri da stiro vedi come balla nando percorsi maturita navigatore satellitare gps medion patente nautica in quiz toto 47 morto www torinoforum it ericsson bus11 diete settimanali turner frederick jackson iaudio u2 512 mb jamboo ===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