minix/servers/is/main.c
Cristiano Giuffrida d1fd04e72a Initialization protocol for system services.
SYSLIB CHANGES:
- SEF framework now supports a new SEF Init request type from RS. 3 different
callbacks are available (init_fresh, init_lu, init_restart) to specify
initialization code when a service starts fresh, starts after a live update,
or restarts.

SYSTEM SERVICE CHANGES:
- Initialization code for system services is now enclosed in a callback SEF will
automatically call at init time. The return code of the callback will
tell RS whether the initialization completed successfully.
- Each init callback can access information passed by RS to initialize. As of
now, each system service has access to the public entries of RS's system process
table to gather all the information required to initialize. This design
eliminates many existing or potential races at boot time and provides a uniform
initialization interface to system services. The same interface will be reused
for the upcoming publish/subscribe model to handle dynamic 
registration / deregistration of system services.

VM CHANGES:
- Uniform privilege management for all system services. Every service uses the
same call mask format. For boot services, VM copies the call mask from init
data. For dynamic services, VM still receives the call mask via rs_set_priv
call that will be soon replaced by the upcoming publish/subscribe model.

RS CHANGES:
- The system process table has been reorganized and split into private entries
and public entries. Only the latter ones are exposed to system services.
- VM call masks are now entirely configured in rs/table.c
- RS has now its own slot in the system process table. Only kernel tasks and
user processes not included in the boot image are now left out from the system
process table.
- RS implements the initialization protocol for system services.
- For services in the boot image, RS blocks till initialization is complete and
panics when failure is reported back. Services are initialized in their order of
appearance in the boot image priv table and RS blocks to implements synchronous
initialization for every system service having the flag SF_SYNCH_BOOT set.
- For services started dynamically, the initialization protocol is implemented
as though it were the first ping for the service. In this case, if the
system service fails to report back (or reports failure), RS brings the service
down rather than trying to restart it.
2010-01-08 01:20:42 +00:00

169 lines
5.5 KiB
C

/* System Information Service.
* This service handles the various debugging dumps, such as the process
* table, so that these no longer directly touch kernel memory. Instead, the
* system task is asked to copy some table in local memory.
*
* Created:
* Apr 29, 2004 by Jorrit N. Herder
*/
#include "inc.h"
#include <minix/endpoint.h>
/* Allocate space for the global variables. */
message m_in; /* the input message itself */
message m_out; /* the output message used for reply */
int who_e; /* caller's proc number */
int callnr; /* system call number */
extern int errno; /* error number set by system library */
/* Declare some local functions. */
FORWARD _PROTOTYPE(void sig_handler, (void) );
FORWARD _PROTOTYPE(void get_work, (void) );
FORWARD _PROTOTYPE(void reply, (int whom, int result) );
/* SEF functions and variables. */
FORWARD _PROTOTYPE( void sef_local_startup, (void) );
FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC int main(int argc, char **argv)
{
/* This is the main routine of this service. The main loop consists of
* three major activities: getting new work, processing the work, and
* sending the reply. The loop never terminates, unless a panic occurs.
*/
int result;
sigset_t sigset;
/* SEF local startup. */
env_setargs(argc, argv);
sef_local_startup();
/* Main loop - get work and do it, forever. */
while (TRUE) {
/* Wait for incoming message, sets 'callnr' and 'who'. */
get_work();
if (is_notify(callnr)) {
switch (_ENDPOINT_P(who_e)) {
case SYSTEM:
printf("got message from SYSTEM\n");
sigset = m_in.NOTIFY_ARG;
for ( result=0; result< _NSIG; result++) {
if (sigismember(&sigset, result))
printf("signal %d found\n", result);
}
continue;
case PM_PROC_NR:
sig_handler();
continue;
case TTY_PROC_NR:
result = do_fkey_pressed(&m_in);
break;
}
}
else {
printf("IS: warning, got illegal request %d from %d\n",
callnr, m_in.m_source);
result = EDONTREPLY;
}
/* Finally send reply message, unless disabled. */
if (result != EDONTREPLY) {
reply(who_e, result);
}
}
return(OK); /* shouldn't come here */
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
PRIVATE void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_lu(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fresh);
/* Register live update callbacks. */
sef_setcb_lu_prepare(sef_cb_lu_prepare_always_ready);
sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid_standard);
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the information server. */
struct sigaction sigact;
/* Install signal handler. Ask PM to transform signal into message. */
sigact.sa_handler = SIG_MESS;
sigact.sa_mask = ~0; /* block all other signals */
sigact.sa_flags = 0; /* default behaviour */
if (sigaction(SIGTERM, &sigact, NULL) < 0)
report("IS","warning, sigaction() failed", errno);
/* Set key mappings. */
map_unmap_fkeys(TRUE /*map*/);
return(OK);
}
/*===========================================================================*
* sig_handler *
*===========================================================================*/
PRIVATE void sig_handler()
{
sigset_t sigset;
/* Try to obtain signal set from PM. */
if (getsigset(&sigset) != 0) return;
/* Only check for termination signal. */
if (!sigismember(&sigset, SIGTERM)) return;
/* Shutting down. Unset key mappings, and quit. */
map_unmap_fkeys(FALSE /*map*/);
exit(0);
}
/*===========================================================================*
* get_work *
*===========================================================================*/
PRIVATE void get_work()
{
int status = 0;
status = sef_receive(ANY, &m_in); /* this blocks until message arrives */
if (OK != status)
panic("IS","sef_receive failed!", status);
who_e = m_in.m_source; /* message arrived! set sender */
callnr = m_in.m_type; /* set function call number */
}
/*===========================================================================*
* reply *
*===========================================================================*/
PRIVATE void reply(who, result)
int who; /* destination */
int result; /* report result to replyee */
{
int send_status;
m_out.m_type = result; /* build reply message */
send_status = send(who, &m_out); /* send the message */
if (OK != send_status)
panic("IS", "unable to send reply!", send_status);
}