int fpm_children_make(struct fpm_worker_pool_s *wp, int in_event_loop, int nb_to_spawn, int is_debug) /* {{{ */
{
pid_t pid;
struct fpm_child_s *child;
int max;
if (wp->config->pm == PM_STYLE_DYNAMIC) {
if (!in_event_loop) { /* starting */
max = wp->config->pm_start_servers;
} else {
max = wp->running_children + nb_to_spawn;
}
} else { /* PM_STYLE_STATIC */
max = wp->config->pm_max_children;
}
while (fpm_pctl_can_spawn_children() && wp->running_children < max) {
child = fpm_resources_prepare(wp);
if (!child) {
return 2;
}
pid = fork();
switch (pid) {
case 0 :
fpm_child_resources_use(child);
fpm_globals.is_child = 1;
fpm_child_init(wp);
return 0;
case -1 :
zlog(ZLOG_SYSERROR, "fork() failed");
fpm_resources_discard(child);
return 2;
default :
child->pid = pid;
fpm_clock_get(&child->started);
fpm_parent_resources_use(child);
zlog(is_debug ? ZLOG_DEBUG : ZLOG_NOTICE, "[pool %s] child %d started", wp->config->name, (int) pid);
}
}
return 1; /* we are done */
}
int fpm_children_make(struct fpm_worker_pool_s *wp, int in_event_loop, int nb_to_spawn, int is_debug) /* {{{ */
{
pid_t pid;
struct fpm_child_s *child;
int max;
static int warned = 0;
//动态模式
if (wp->config->pm == PM_STYLE_DYNAMIC) {
if (!in_event_loop) { /* starting */
max = wp->config->pm_start_servers;
} else {
max = wp->running_children + nb_to_spawn;
}
} else if (wp->config->pm == PM_STYLE_ONDEMAND) {
//ondemand模式
if (!in_event_loop) { /* starting */
max = 0; /* do not create any child at startup */
} else {
max = wp->running_children + nb_to_spawn;
}
} else { /* PM_STYLE_STATIC */
//静态模式
max = wp->config->pm_max_children;
}
/*
* fork children while:
* - fpm_pctl_can_spawn_children : FPM is running in a NORMAL state (aka not restart, stop or reload)
* - wp->running_children < max : there is less than the max process for the current pool
* - (fpm_global_config.process_max < 1 || fpm_globals.running_children < fpm_global_config.process_max):
* if fpm_global_config.process_max is set, FPM has not fork this number of processes (globaly)
*/
//当执行restart、stop、reload命令时，fpm_pctl_can_spawn_children()为false
while (fpm_pctl_can_spawn_children() && wp->running_children < max && (fpm_global_config.process_max < 1 || fpm_globals.running_children < fpm_global_config.process_max)) {
warned = 0;
child = fpm_resources_prepare(wp);
if (!child) {
return 2;
}
//fork子进程
pid = fork();
switch (pid) {
case 0 :
fpm_child_resources_use(child);
fpm_globals.is_child = 1;
//子进程初始化
fpm_child_init(wp);
return 0;
case -1 :
zlog(ZLOG_SYSERROR, "fork() failed");
fpm_resources_discard(child);
return 2;
default :
child->pid = pid;
fpm_clock_get(&child->started);
fpm_parent_resources_use(child);
zlog(is_debug ? ZLOG_DEBUG : ZLOG_NOTICE, "[pool %s] child %d started", wp->config->name, (int) pid);
}
}
if (!warned && fpm_global_config.process_max > 0 && fpm_globals.running_children >= fpm_global_config.process_max) {
warned = 1;
zlog(ZLOG_WARNING, "The maximum number of processes has been reached. Please review your configuration and consider raising 'process.max'");
}
return 1; /* we are done */
}