int test(){ #ifdef _OSD_POSIX if ((pid = os_fork(ap_unixd_config.user_name)) == -1) { #else if ((pid = fork()) == -1) { #endif // code } }
static int make_child(server_rec *s, int slot) { int pid; if (slot + 1 > ap_max_daemons_limit) { ap_max_daemons_limit = slot + 1; } if (one_process) { apr_signal(SIGHUP, just_die); /* Don't catch AP_SIG_GRACEFUL in ONE_PROCESS mode :) */ apr_signal(SIGINT, just_die); #ifdef SIGQUIT apr_signal(SIGQUIT, SIG_DFL); #endif apr_signal(SIGTERM, just_die); child_main(slot); } (void) ap_update_child_status_from_indexes(slot, 0, SERVER_STARTING, (request_rec *) NULL); #ifdef _OSD_POSIX /* BS2000 requires a "special" version of fork() before a setuid() call */ if ((pid = os_fork(unixd_config.user_name)) == -1) { #elif defined(TPF) if ((pid = os_fork(s, slot)) == -1) { #else if ((pid = fork()) == -1) { #endif ap_log_error(APLOG_MARK, APLOG_ERR, errno, s, "fork: Unable to fork new process"); /* fork didn't succeed. Fix the scoreboard or else * it will say SERVER_STARTING forever and ever */ (void) ap_update_child_status_from_indexes(slot, 0, SERVER_DEAD, (request_rec *) NULL); /* In case system resources are maxxed out, we don't want Apache running away with the CPU trying to fork over and over and over again. */ sleep(10); return -1; } if (!pid) { #ifdef HAVE_BINDPROCESSOR /* by default AIX binds to a single processor * this bit unbinds children which will then bind to another cpu */ int status = bindprocessor(BINDPROCESS, (int)getpid(), PROCESSOR_CLASS_ANY); if (status != OK) { ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "processor unbind failed %d", status); } #endif RAISE_SIGSTOP(MAKE_CHILD); AP_MONCONTROL(1); /* Disable the parent's signal handlers and set up proper handling in * the child. */ apr_signal(SIGHUP, just_die); apr_signal(SIGTERM, just_die); /* The child process doesn't do anything for AP_SIG_GRACEFUL. * Instead, the pod is used for signalling graceful restart. */ apr_signal(AP_SIG_GRACEFUL, SIG_IGN); child_main(slot); } ap_scoreboard_image->parent[slot].pid = pid; return 0; } /* start up a bunch of children */ static void startup_children(int number_to_start) { int i; for (i = 0; number_to_start && i < ap_daemons_limit; ++i) { if (ap_scoreboard_image->servers[i][0].status != SERVER_DEAD) { continue; } if (make_child(ap_server_conf, i) < 0) { break; } --number_to_start; } } /* * idle_spawn_rate is the number of children that will be spawned on the * next maintenance cycle if there aren't enough idle servers. It is * doubled up to MAX_SPAWN_RATE, and reset only when a cycle goes by * without the need to spawn. */ static int idle_spawn_rate = 1; #ifndef MAX_SPAWN_RATE #define MAX_SPAWN_RATE (32) #endif static int hold_off_on_exponential_spawning; static void perform_idle_server_maintenance(apr_pool_t *p) { int i; int to_kill; int idle_count; worker_score *ws; int free_length; int free_slots[MAX_SPAWN_RATE]; int last_non_dead; int total_non_dead; /* initialize the free_list */ free_length = 0; to_kill = -1; idle_count = 0; last_non_dead = -1; total_non_dead = 0; for (i = 0; i < ap_daemons_limit; ++i) { int status; if (i >= ap_max_daemons_limit && free_length == idle_spawn_rate) break; ws = &ap_scoreboard_image->servers[i][0]; status = ws->status; if (status == SERVER_DEAD) { /* try to keep children numbers as low as possible */ if (free_length < idle_spawn_rate) { free_slots[free_length] = i; ++free_length; } } else { /* We consider a starting server as idle because we started it * at least a cycle ago, and if it still hasn't finished starting * then we're just going to swamp things worse by forking more. * So we hopefully won't need to fork more if we count it. * This depends on the ordering of SERVER_READY and SERVER_STARTING. */ if (status <= SERVER_READY) { ++ idle_count; /* always kill the highest numbered child if we have to... * no really well thought out reason ... other than observing * the server behaviour under linux where lower numbered children * tend to service more hits (and hence are more likely to have * their data in cpu caches). */ to_kill = i; } ++total_non_dead; last_non_dead = i; } } ap_max_daemons_limit = last_non_dead + 1; if (idle_count > ap_daemons_max_free) { /* kill off one child... we use the pod because that'll cause it to * shut down gracefully, in case it happened to pick up a request * while we were counting */ ap_mpm_pod_signal(pod); idle_spawn_rate = 1; } else if (idle_count < ap_daemons_min_free) { /* terminate the free list */ if (free_length == 0) { /* only report this condition once */ static int reported = 0; if (!reported) { ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf, "server reached MaxClients setting, consider" " raising the MaxClients setting"); reported = 1; } idle_spawn_rate = 1; } else { if (idle_spawn_rate >= 8) { ap_log_error(APLOG_MARK, APLOG_INFO, 0, ap_server_conf, "server seems busy, (you may need " "to increase StartServers, or Min/MaxSpareServers), " "spawning %d children, there are %d idle, and " "%d total children", idle_spawn_rate, idle_count, total_non_dead); } for (i = 0; i < free_length; ++i) { #ifdef TPF if (make_child(ap_server_conf, free_slots[i]) == -1) { if(free_length == 1) { shutdown_pending = 1; ap_log_error(APLOG_MARK, APLOG_EMERG, 0, ap_server_conf, "No active child processes: shutting down"); } } #else make_child(ap_server_conf, free_slots[i]); #endif /* TPF */ } /* the next time around we want to spawn twice as many if this * wasn't good enough, but not if we've just done a graceful */ if (hold_off_on_exponential_spawning) { --hold_off_on_exponential_spawning; } else if (idle_spawn_rate < MAX_SPAWN_RATE) { idle_spawn_rate *= 2; } } } else { idle_spawn_rate = 1; } }