201 lines
5.7 KiB
Plaintext
201 lines
5.7 KiB
Plaintext
--------------------------------------------------------------------------------
|
|
/etc/cinit
|
|
-> init/
|
|
-> shutdown/
|
|
-> reboot/
|
|
|
|
<service>
|
|
needs/ -> we wait until all parallel processes are finished _and_ we
|
|
don't start if one fails
|
|
wants/ -> we start all of them parallel and wait for them?
|
|
hold/
|
|
wait -> wait until process finished
|
|
run -> program to execute
|
|
params -> \n seperated argument list
|
|
respawn -> respawn it
|
|
|
|
services may only be under /etc/cinit?
|
|
--------------------------------------------------------------------------------
|
|
Service-Status: (see struct svc, cinit.h)
|
|
|
|
- abs_path
|
|
- status (respawn,tmp,once)
|
|
- pid
|
|
|
|
abs_path\0status\0pid\0
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
starting services:
|
|
|
|
run_svc("/etc/cinit/service/")
|
|
-> exec run $params
|
|
Later:
|
|
-> check if service already running -> return OK
|
|
-> check needs/ -> check wants/
|
|
-> run_svc($cur)
|
|
|
|
When run_svc returns, the service is started and all service it needs, too.
|
|
|
|
|
|
--------------------------------------------------------------------------------
|
|
-> check needs/
|
|
-> exists -> fork( run_run_svcs() ) and continue
|
|
(fork) -> fork() run_svc(needs/*);
|
|
-> check wants/
|
|
-> exists -> run_svc(wants/*);
|
|
-> waitfor(need_run_svc)
|
|
--------------------------------------------------------------------------------
|
|
run_run_svcs()
|
|
-> start parallel (forked) run_svc() for every service
|
|
--------------------------------------------------------------------------------
|
|
|
|
main()
|
|
- run_svc /etc/cinit/init/
|
|
- sleep()? -> simply do nothing -> do we need to fork ourselves? No, we are init.
|
|
spaeter:
|
|
- open /dev/console W_ONLY
|
|
- make stdin == /etc/cinit/in
|
|
- make stdout, stderr /dev/console
|
|
|
|
--------------------------------------------------------------------------------
|
|
eof
|
|
|
|
Things, which are clear
|
|
|
|
- we need to fork before execl(), as excel() replaces us.
|
|
- chdir() _after_ fork()
|
|
|
|
|
|
profiles support: profile=$profile
|
|
|
|
start
|
|
"service.$profile" if exists, instead of
|
|
"service"
|
|
|
|
starting services:
|
|
|
|
cinit:
|
|
pipe()
|
|
set_status_tmp()
|
|
fork() --> failure --> clear_service
|
|
cinit_process_watcher():
|
|
fork()
|
|
execve(process,args,env)
|
|
waitpid() -> for once? PROCESS MUST RETURN!
|
|
write_pipe()
|
|
rmpipe()
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
What to send over to cinit and read back?
|
|
|
|
- first you need two pipes for every process: read+write (on both sides)
|
|
- cinit wants
|
|
o command
|
|
- service temporary - trying to start in right now.
|
|
- service executed once - fine
|
|
- service executed once and that failed - :-(
|
|
- service respawing
|
|
o an identifier for the service (i from service list ;-)
|
|
|
|
--> makes 2 bytes to read
|
|
--------------------------------------------------------------------------------
|
|
How cinit works:
|
|
|
|
cinit says: I want to start service xyz. (/etc/cinit/init on bootup)
|
|
cinit calls run_svc().
|
|
--------------------------------------------------------------------------------
|
|
|
|
int run_svc(char *relative_path):
|
|
- check if service is already running or temporary (task list!)
|
|
-> yes: return RT_PAR_OK
|
|
-> no: continue.
|
|
- set service to be temporary (ST_TMP) and retrieve SID (service ID)
|
|
- walk through dependency tree and call run_svc
|
|
- fork() -> so cinit can continue.
|
|
- write cinit: check service, I want to start it
|
|
-> returns status of service (see ST_* in cinit.h)
|
|
- cinit returns: ok, you are temporary
|
|
- [that checked] check if service
|
|
o is already started
|
|
o is beeing started
|
|
x check if rpath S_ISDIR
|
|
x chdir(dir)
|
|
- check needs - check wants
|
|
- for every needs/* start run_svc
|
|
- check respawn -> respawn = true
|
|
- check run
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
add_mod_svc(char *svc, int status)
|
|
-> add or modify status of a service
|
|
|
|
- check whether service exists, reset status
|
|
- if not exists, insert if maximum of services is not reached
|
|
--------------------------------------------------------------------------------
|
|
|
|
cinit communications proto
|
|
--------------------------------------------------------------------------------
|
|
|
|
cinit:
|
|
-> signal_handler on SIGCHLD
|
|
run_init()
|
|
-> run_svc(init)
|
|
-> fork() -> do the work
|
|
|
|
signal_handler_child
|
|
waitpid(.*)
|
|
-> returns pid
|
|
|
|
oder waitpid() in dem run_svc, wenn need/once?
|
|
|
|
need:
|
|
for i in need/*; do
|
|
( $service & );
|
|
done
|
|
wait(.*);
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
cinit:
|
|
|
|
run_svc:
|
|
checks what it needs (need/*)
|
|
need/*
|
|
fork()
|
|
fork(), fork()
|
|
|
|
--------------------------------------------------------------------------------
|
|
Kommunikationsproblem:
|
|
|
|
-> 1024 ist maximale anzahl offener sockets -> 510 von fifos,pipes
|
|
- mehrere FIFOs?
|
|
--> kommunikation gesichert, extrem viele fifos...
|
|
--> etwas unsauber, aber geregelte kommunikation
|
|
- mehrere PIPEs?
|
|
--> viele PIPEs (HRHR)
|
|
--> programme koennen nur von cinit gefork()ed werden.
|
|
|
|
--> eine datei mit prozessen?
|
|
--> einen RAM Bereich?
|
|
--------------------------------------------------------------------------------
|
|
|
|
cinit[1] <-> fifo <-> forker
|
|
|
|
forker?
|
|
--------------------------------------------------------------------------------
|
|
|
|
pfad vorher aufloesen?
|
|
|
|
--------------------------------------------------------------------------------
|
|
Kommunikation: ::Test::
|
|
|
|
Test mit nur 2 FIFOs!
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
sig_fifo()
|
|
read(..) als hauptaufgabe?
|