static void master_avail_event(int event, char *context)
{
MASTER_SERV *serv = (MASTER_SERV *) context;
time_t now;
if (event == 0) /* XXX Can this happen? */
msg_panic("master_avail_event: null event");
else {
/*
* When all servers for a public internet service are busy, we start
* creating server processes with "-o stress=yes" on the command
* line, and keep creating such processes until the process count is
* below the limit for at least 1000 seconds. This provides a minimal
* solution that can be adopted into legacy and stable Postfix
* releases.
*
* This is not the right place to update serv->stress_param_val in
* response to stress level changes. Doing so would would contaminate
* the "postfix reload" code with stress management implementation
* details, creating a source of future bugs. Instead, we update
* simple counters or flags here, and use their values to determine
* the proper serv->stress_param_val value when exec-ing a server
* process.
*/
if (serv->stress_param_val != 0
&& !MASTER_LIMIT_OK(serv->max_proc, serv->total_proc + 1)) {
now = event_time();
if (serv->stress_expire_time < now)
master_restart_service(serv, NO_CONF_RELOAD);
serv->stress_expire_time = now + 1000;
}
master_spawn(serv);
}
}
void master_config(void)
{
MASTER_SERV *entry;
MASTER_SERV *serv;
#define STR_DIFF strcmp
#define STR_SAME !strcmp
#define SWAP(type,a,b) { type temp = a; a = b; b = temp; }
/*
* A service is identified by its endpoint name AND by its transport
* type, not just by its name alone. The name is unique within its
* transport type. XXX Service privacy is encoded in the service name.
*/
set_master_ent();
while ((entry = get_master_ent()) != 0) {
if (msg_verbose)
print_master_ent(entry);
for (serv = master_head; serv != 0; serv = serv->next)
if (STR_SAME(serv->name, entry->name) && serv->type == entry->type)
break;
/*
* Add a new service entry. We do not really care in what order the
* service entries are kept in memory.
*/
if (serv == 0) {
entry->next = master_head;
master_head = entry;
master_start_service(entry);
}
/*
* Update an existing service entry. Make the current generation of
* child processes commit suicide whenever it is convenient. The next
* generation of child processes will run with the new configuration
* settings.
*/
else {
serv->flags &= ~MASTER_FLAG_MARK;
if (entry->flags & MASTER_FLAG_CONDWAKE)
serv->flags |= MASTER_FLAG_CONDWAKE;
else
serv->flags &= ~MASTER_FLAG_CONDWAKE;
serv->wakeup_time = entry->wakeup_time;
serv->max_proc = entry->max_proc;
serv->throttle_delay = entry->throttle_delay;
SWAP(char *, serv->ext_name, entry->ext_name);
SWAP(char *, serv->path, entry->path);
SWAP(ARGV *, serv->args, entry->args);
SWAP(char *, serv->stress_param_val, entry->stress_param_val);
master_restart_service(serv, DO_CONF_RELOAD);
free_master_ent(entry);
}
}
end_master_ent();
}