/*
* Copyright (C) Igor Sysoev
* Copyright (C) NGINX, Inc.
*/
#include <nxt_main.h>
#include <nxt_cycle.h>
#include <nxt_process_chan.h>
#include <nxt_master_process.h>
static nxt_int_t nxt_master_process_chan_create(nxt_cycle_t *cycle);
static void nxt_master_process_title(void);
static nxt_int_t nxt_master_start_worker_processes(nxt_cycle_t *cycle);
static nxt_int_t nxt_master_create_worker_process(nxt_cycle_t *cycle);
static void nxt_master_stop_previous_worker_processes(nxt_thread_t *thr,
void *obj, void *data);
static void nxt_master_process_sighup_handler(nxt_thread_t *thr, void *obj,
void *data);
static void nxt_master_process_new_cycle(nxt_thread_t *thr, nxt_cycle_t *cycle);
static void nxt_master_process_sigterm_handler(nxt_thread_t *thr, void *obj,
void *data);
static void nxt_master_process_sigquit_handler(nxt_thread_t *thr, void *obj,
void *data);
static void nxt_master_process_sigusr1_handler(nxt_thread_t *thr, void *obj,
void *data);
static void nxt_master_process_sigusr2_handler(nxt_thread_t *thr, void *obj,
void *data);
static char **nxt_master_process_upgrade_environment(nxt_cycle_t *cycle);
static char **nxt_master_process_upgrade_environment_create(nxt_cycle_t *cycle);
static void nxt_master_process_sigchld_handler(nxt_thread_t *thr, void *obj,
void *data);
static void nxt_master_cleanup_worker_process(nxt_thread_t *thr, nxt_pid_t pid);
const nxt_event_sig_t nxt_master_process_signals[] = {
nxt_event_signal(SIGHUP, nxt_master_process_sighup_handler),
nxt_event_signal(SIGINT, nxt_master_process_sigterm_handler),
nxt_event_signal(SIGQUIT, nxt_master_process_sigquit_handler),
nxt_event_signal(SIGTERM, nxt_master_process_sigterm_handler),
nxt_event_signal(SIGCHLD, nxt_master_process_sigchld_handler),
nxt_event_signal(SIGUSR1, nxt_master_process_sigusr1_handler),
nxt_event_signal(SIGUSR2, nxt_master_process_sigusr2_handler),
nxt_event_signal_end,
};
static nxt_bool_t nxt_exiting;
nxt_int_t
nxt_master_process_start(nxt_thread_t *thr, nxt_cycle_t *cycle)
{
cycle->type = NXT_PROCESS_MASTER;
if (nxt_master_process_chan_create(cycle) != NXT_OK) {
return NXT_ERROR;
}
nxt_master_process_title();
return nxt_master_start_worker_processes(cycle);
}
static nxt_int_t
nxt_master_process_chan_create(nxt_cycle_t *cycle)
{
nxt_process_chan_t *proc;
proc = nxt_array_add(cycle->processes);
if (nxt_slow_path(proc == NULL)) {
return NXT_ERROR;
}
proc->pid = nxt_pid;
proc->engine = 0;
proc->chan = nxt_chan_create(0);
if (nxt_slow_path(proc->chan == NULL)) {
return NXT_ERROR;
}
/*
* A master process chan. A write chan is not closed
* since it should be inherited by worker processes.
*/
nxt_chan_read_enable(nxt_thread(), proc->chan);
return NXT_OK;
}
static void
nxt_master_process_title(void)
{
u_char *p, *end;
nxt_uint_t i;
u_char title[2048];
end = title + sizeof(title);
p = nxt_sprintf(title, end, "nginman: master process %s",
nxt_process_argv[0]);
for (i = 1; nxt_process_argv[i] != NULL; i++) {
p = nxt_sprintf(p, end, " %s", nxt_process_argv[i]);
}
*p = '\0';
nxt_process_title((char *) title);
}
static nxt_int_t
nxt_master_start_worker_processes(nxt_cycle_t *cycle)
{
nxt_int_t ret;
nxt_uint_t n;
cycle->process_generation++;
n = cycle->worker_processes;
while (n-- != 0) {
ret = nxt_master_create_worker_process(cycle);
if (ret != NXT_OK) {
return ret;
}
}
return NXT_OK;
}
static nxt_int_t
nxt_master_create_worker_process(nxt_cycle_t *cycle)
{
nxt_pid_t pid;
nxt_process_chan_t *proc;
proc = nxt_array_add(cycle->processes);
if (nxt_slow_path(proc == NULL)) {
return NXT_ERROR;
}
cycle->current_process = cycle->processes->nelts - 1;
proc->engine = 0;
proc->generation = cycle->process_generation;
proc->chan = nxt_chan_create(0);
if (nxt_slow_path(proc->chan == NULL)) {
return NXT_ERROR;
}
pid = nxt_process_create(nxt_worker_process_start, cycle,
"start worker process");
switch (pid) {
case -1:
return NXT_ERROR;
case 0:
/* A worker process, return to the event engine work queue loop. */
return NXT_AGAIN;
default:
/* The master process created a new process. */
proc->pid = pid;
nxt_chan_read_close(proc->chan);
nxt_chan_write_enable(nxt_thread(), proc->chan);
nxt_process_new_chan(cycle, proc);
return NXT_OK;
}
}
static void
nxt_master_process_sighup_handler(nxt_thread_t *thr, void *obj, void *data)
{
nxt_cycle_t *cycle;
cycle = nxt_thread_cycle();
nxt_log_error(NXT_LOG_NOTICE, thr->log, "signal %d (%s) recevied, %s",
(int) (uintptr_t) obj, data,
cycle->reconfiguring ? "ignored" : "reconfiguring");
if (!cycle->reconfiguring) {
(void) nxt_cycle_create(thr, cycle, nxt_master_process_new_cycle,
cycle->config_name, 0);
}
}
static void
nxt_master_process_new_cycle(nxt_thread_t *thr, nxt_cycle_t *cycle)
{
nxt_log_debug(thr->log, "new cycle");
/* A safe place to free the previous cycle. */
nxt_mem_pool_destroy(cycle->previous->mem_pool);
switch (nxt_master_start_worker_processes(cycle)) {
case NXT_OK:
/*
* The master process, allow old worker processes to accept new
* connections yet 500ms in parallel with new worker processes.
*/
cycle->timer.handler = nxt_master_stop_previous_worker_processes;
cycle->timer.log = &nxt_main_log;
nxt_event_timer_ident(&cycle->timer, -1);
cycle->timer.work_queue = &thr->work_queue.main;
nxt_event_timer_add(thr->engine, &cycle->timer, 500);
return;
case NXT_ERROR:
/*
* The master process, one or more new worker processes
* could not be created, there is no fallback.
*/
return;
default: /* NXT_AGAIN */
/* A worker process, return to the event engine work queue loop. */
return;
}
}
static void
nxt_master_stop_previous_worker_processes(nxt_thread_t *thr, void *obj,
void *data)
{
uint32_t generation;
nxt_uint_t i, n;
nxt_cycle_t *cycle;
nxt_process_chan_t *proc;
cycle = nxt_thread_cycle();
proc = cycle->processes->elts;
n = cycle->processes->nelts;
generation = cycle->process_generation - 1;
/* The proc[0] is the master process. */
for (i = 1; i < n; i++) {
if (proc[i].generation == generation) {
(void) nxt_chan_write(proc[i].chan, NXT_CHAN_MSG_QUIT, -1, 0, NULL);
}
}
cycle->reconfiguring = 0;
}
void
nxt_master_stop_worker_processes(nxt_cycle_t *cycle)
{
nxt_process_chan_write(cycle, NXT_CHAN_MSG_QUIT, -1, 0, NULL);
}
static void
nxt_master_process_sigterm_handler(nxt_thread_t *thr, void *obj, void *data)
{
nxt_log_debug(thr->log, "sigterm handler signo:%d (%s)",
(int) (uintptr_t) obj, data);
/* TODO: fast exit. */
nxt_exiting = 1;
nxt_cycle_quit(thr, NULL);
}
static void
nxt_master_process_sigquit_handler(nxt_thread_t *thr, void *obj, void *data)
{
nxt_log_debug(thr->log, "sigquit handler signo:%d (%s)",
(int) (uintptr_t) obj, data);
/* TODO: graceful exit. */
nxt_exiting = 1;
nxt_cycle_quit(thr, NULL);
}
static void
nxt_master_process_sigusr1_handler(nxt_thread_t *thr, void *obj, void *data)
{
nxt_int_t ret;
nxt_uint_t n;
nxt_file_t *file, *new_file;
nxt_cycle_t *cycle;
nxt_array_t *new_files;
nxt_mem_pool_t *mp;
nxt_log_error(NXT_LOG_NOTICE, thr->log, "signal %d (%s) recevied, %s",
(int) (uintptr_t) obj, data, "log files rotation");
mp = nxt_mem_pool_create(1024);
if (mp == NULL) {
return;
}
cycle = nxt_thread_cycle();
n = nxt_list_nelts(cycle->log_files);
new_files = nxt_array_create(mp, n, sizeof(nxt_file_t));
if (new_files == NULL) {
nxt_mem_pool_destroy(mp);
return;
}
nxt_list_each(file, cycle->log_files) {
/* This allocation cannot fail. */
new_file = nxt_array_add(new_files);
new_file->name = file->name;
new_file->fd = NXT_FILE_INVALID;
new_file->log_level = NXT_LOG_CRIT;
ret = nxt_file_open(new_file, NXT_FILE_APPEND, NXT_FILE_CREATE_OR_OPEN,
NXT_FILE_OWNER_ACCESS);
if (ret != NXT_OK) {
goto fail;
}
} nxt_list_loop;
new_file = new_files->elts;
ret = nxt_file_stderr(&new_file[0]);
if (ret == NXT_OK) {
n = 0;
nxt_list_each(file, cycle->log_files) {
nxt_process_chan_change_log_file(cycle, n, new_file[n].fd);
/*
* The old log file descriptor must be closed at the moment
* when no other threads use it. dup2() allows to use the
* old file descriptor for new log file. This change is
* performed atomically in the kernel.
*/
(void) nxt_file_redirect(file, new_file[n].fd);
n++;
} nxt_list_loop;
nxt_mem_pool_destroy(mp);
return;
}
fail:
new_file = new_files->elts;
n = new_files->nelts;
while (n != 0) {
if (new_file->fd != NXT_FILE_INVALID) {
nxt_file_close(new_file);
}
new_file++;
n--;
}
nxt_mem_pool_destroy(mp);
}
static void
nxt_master_process_sigusr2_handler(nxt_thread_t *thr, void *obj, void *data)
{
char **env;
nxt_int_t ret;
nxt_pid_t pid, ppid;
nxt_bool_t ignore;
nxt_cycle_t *cycle;
cycle = nxt_thread_cycle();
/* Is upgrade or reconfiguring in progress? */
ignore = (cycle->new_binary != 0) || cycle->reconfiguring;
ppid = getppid();
if (ppid == nxt_ppid && ppid != 1) {
/*
* Ignore the upgrade signal in a new master process if an old
* master process is still running. After the old process's exit
* getppid() will return 1 (init process pid) or pid of zsched (zone
* scheduler) if the processes run in Solaris zone. There is little
* race condition between the parent process exit and getting getppid()
* for the very start of the new master process execution, so init or
* zsched pid may be stored in nxt_ppid. For this reason pid 1 is
* tested explicitly. There is no workaround for this race condition
* in Solaris zons. To eliminate this race condition in Solaris
* zone the old master process should be quit only when both
* "nginman.pid.oldbin" (created by the old master process) and
* "nginman.pid" (created by the new master process) files exists.
*/
ignore = 1;
}
nxt_log_error(NXT_LOG_NOTICE, thr->log,
"signal %d (%s) recevied, %s, parent pid: %PI",
(int) (uintptr_t) obj, data,
ignore ? "ignored" : "online binary file upgrade", ppid);
if (ignore) {
return;
}
env = nxt_master_process_upgrade_environment(cycle);
if (nxt_slow_path(env == NULL)) {
return;
}
cycle->new_binary = -1;
ret = nxt_cycle_pid_file_create(cycle->oldbin_file, 0);
if (nxt_slow_path(ret != NXT_OK)) {
goto fail;
}
pid = nxt_process_execute(nxt_process_argv[0], nxt_process_argv, env);
if (pid == -1) {
cycle->new_binary = 0;
(void) nxt_file_delete(cycle->oldbin_file);
} else {
cycle->new_binary = pid;
}
fail:
/* Zero slot is NGINX variable slot, all other slots must not be free()d. */
nxt_free(env[0]);
nxt_free(env);
}
static char **
nxt_master_process_upgrade_environment(nxt_cycle_t *cycle)
{
size_t len;
char **env;
u_char *p, *end;
nxt_uint_t n;
nxt_listen_socket_t *ls;
env = nxt_master_process_upgrade_environment_create(cycle);
if (nxt_slow_path(env == NULL)) {
return NULL;
}
ls = cycle->listen_sockets->elts;
n = cycle->listen_sockets->nelts;
len = sizeof("NGINX=") + n * (NXT_INT_T_LEN + 1);
p = nxt_malloc(len);
if (nxt_slow_path(p == NULL)) {
nxt_free(env);
return NULL;
}
env[0] = (char *) p;
end = p + len;
p = nxt_cpymem(p, "NGINX=", sizeof("NGINX=") - 1);
do {
p = nxt_sprintf(p, end, "%ud;", ls->socket);
ls++;
n--;
} while (n != 0);
*p = '\0';
return env;
}
static char **
nxt_master_process_upgrade_environment_create(nxt_cycle_t *cycle)
{
char **env;
nxt_uint_t n;
/* 2 is for "NGINX" variable and the last NULL slot. */
n = 2;
#if (NXT_SETPROCTITLE_ARGV)
n++;
#endif
env = nxt_malloc(n * sizeof(char *));
if (nxt_slow_path(env == NULL)) {
return NULL;
}
/* Zero slot is reserved for "NGINX" variable. */
n = 1;
/* TODO: copy env values */
#if (NXT_SETPROCTITLE_ARGV)
/* 300 spare bytes for new process title. */
env[n++] = (char *)
"SPARE=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
#endif
env[n] = NULL;
return env;
}
static void
nxt_master_process_sigchld_handler(nxt_thread_t *thr, void *obj, void *data)
{
int status;
nxt_err_t err;
nxt_pid_t pid;
nxt_log_debug(thr->log, "sigchld handler signo:%d (%s)",
(int) (uintptr_t) obj, data);
for ( ;; ) {
pid = waitpid(-1, &status, WNOHANG);
if (pid == -1) {
switch (err = nxt_errno) {
case NXT_ECHILD:
return;
case NXT_EINTR:
continue;
default:
nxt_log_alert(thr->log, "waitpid() failed: %E", err);
return;
}
}
nxt_log_debug(thr->log, "waitpid(): %PI", pid);
if (pid == 0) {
return;
}
if (WTERMSIG(status)) {
#ifdef WCOREDUMP
nxt_log_alert(thr->log, "process %PI exited on signal %d%s",
pid, WTERMSIG(status),
WCOREDUMP(status) ? " (core dumped)" : "");
#else
nxt_log_alert(thr->log, "process %PI exited on signal %d",
pid, WTERMSIG(status));
#endif
} else {
nxt_log_error(NXT_LOG_NOTICE, thr->log,
"process %PI exited with code %d",
pid, WEXITSTATUS(status));
}
nxt_master_cleanup_worker_process(thr, pid);
}
}
static void
nxt_master_cleanup_worker_process(nxt_thread_t *thr, nxt_pid_t pid)
{
nxt_uint_t i, n, generation;
nxt_cycle_t *cycle;
nxt_process_chan_t *proc;
cycle = nxt_thread_cycle();
if (cycle->new_binary == pid) {
cycle->new_binary = 0;
(void) nxt_file_rename(cycle->oldbin_file, cycle->pid_file);
return;
}
proc = cycle->processes->elts;
n = cycle->processes->nelts;
for (i = 0; i < n; i++) {
if (pid == proc[i].pid) {
generation = proc[i].generation;
nxt_array_remove(cycle->processes, &proc[i]);
if (nxt_exiting) {
nxt_log_debug(thr->log, "processes %d", n);
if (n == 2) {
nxt_cycle_quit(thr, cycle);
}
} else if (generation == cycle->process_generation) {
(void) nxt_master_create_worker_process(cycle);
}
return;
}
}
}
