void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
u_long nev, ev, timeout;
ngx_err_t err;
ngx_int_t n;
ngx_msec_t timer;
ngx_uint_t live;
HANDLE events[MAXIMUM_WAIT_OBJECTS];
ngx_sprintf((u_char *) ngx_master_process_event_name,
"ngx_master_%s%Z", ngx_unique);
if (ngx_process == NGX_PROCESS_WORKER) {
ngx_worker_process_cycle(cycle, ngx_master_process_event_name);
return;
}
ngx_log_debug0(NGX_LOG_DEBUG_CORE, cycle->log, 0, "master started");
ngx_console_init(cycle);
SetEnvironmentVariable("ngx_unique", ngx_unique);
ngx_master_process_event = CreateEvent(NULL, 1, 0,
ngx_master_process_event_name);
if (ngx_master_process_event == NULL) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"CreateEvent(\"%s\") failed",
ngx_master_process_event_name);
exit(2);
}
if (ngx_create_signal_events(cycle) != NGX_OK) {
exit(2);
}
ngx_sprintf((u_char *) ngx_cache_manager_mutex_name,
"ngx_cache_manager_mutex_%s%Z", ngx_unique);
ngx_cache_manager_mutex = CreateMutex(NULL, 0,
ngx_cache_manager_mutex_name);
if (ngx_cache_manager_mutex == NULL) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"CreateMutex(\"%s\") failed", ngx_cache_manager_mutex_name);
exit(2);
}
events[0] = ngx_stop_event;
events[1] = ngx_quit_event;
events[2] = ngx_reopen_event;
events[3] = ngx_reload_event;
ngx_close_listening_sockets(cycle);
if (ngx_start_worker_processes(cycle, NGX_PROCESS_RESPAWN) == 0) {
exit(2);
}
timer = 0;
timeout = INFINITE;
for ( ;; ) {
nev = 4;
for (n = 0; n < ngx_last_process; n++) {
if (ngx_processes[n].handle) {
events[nev++] = ngx_processes[n].handle;
}
}
if (timer) {
timeout = timer > ngx_current_msec ? timer - ngx_current_msec : 0;
}
ev = WaitForMultipleObjects(nev, events, 0, timeout);
err = ngx_errno;
ngx_time_update();
ngx_log_debug1(NGX_LOG_DEBUG_CORE, cycle->log, 0,
"master WaitForMultipleObjects: %ul", ev);
if (ev == WAIT_OBJECT_0) {
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");
if (ResetEvent(ngx_stop_event) == 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"ResetEvent(\"%s\") failed", ngx_stop_event_name);
}
if (timer == 0) {
timer = ngx_current_msec + 5000;
}
ngx_terminate = 1;
ngx_quit_worker_processes(cycle, 0);
continue;
}
if (ev == WAIT_OBJECT_0 + 1) {
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "shutting down");
if (ResetEvent(ngx_quit_event) == 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"ResetEvent(\"%s\") failed", ngx_quit_event_name);
}
ngx_quit = 1;
ngx_quit_worker_processes(cycle, 0);
continue;
}
if (ev == WAIT_OBJECT_0 + 2) {
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
if (ResetEvent(ngx_reopen_event) == 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"ResetEvent(\"%s\") failed",
ngx_reopen_event_name);
}
ngx_reopen_files(cycle, -1);
ngx_reopen_worker_processes(cycle);
continue;
}
if (ev == WAIT_OBJECT_0 + 3) {
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
if (ResetEvent(ngx_reload_event) == 0) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"ResetEvent(\"%s\") failed",
ngx_reload_event_name);
}
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ngx_close_listening_sockets(cycle);
if (ngx_start_worker_processes(cycle, NGX_PROCESS_JUST_RESPAWN)) {
ngx_quit_worker_processes(cycle, 1);
}
continue;
}
if (ev > WAIT_OBJECT_0 + 3 && ev < WAIT_OBJECT_0 + nev) {
ngx_log_debug0(NGX_LOG_DEBUG_CORE, cycle->log, 0, "reap worker");
live = ngx_reap_worker(cycle, events[ev]);
if (!live && (ngx_terminate || ngx_quit)) {
ngx_master_process_exit(cycle);
}
continue;
}
if (ev == WAIT_TIMEOUT) {
ngx_terminate_worker_processes(cycle);
ngx_master_process_exit(cycle);
}
if (ev == WAIT_FAILED) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
"WaitForMultipleObjects() failed");
continue;
}
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"WaitForMultipleObjects() returned unexpected value %ul", ev);
}
}
// http://www.xuebuyuan.com/557917.html
// http://blog.csdn.net/lu_ming/article/details/5144427
// http://blog.csdn.net/lengzijian/article/details/7587740
void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
char *title;
u_char *p;
size_t size;
ngx_int_t i;
ngx_uint_t n, sigio;
sigset_t set;
struct itimerval itv;
ngx_uint_t live;
ngx_msec_t delay;
ngx_listening_t *ls;
ngx_core_conf_t *ccf;
// block these signals
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGALRM);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGINT);
sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigprocmask() failed");
}
sigemptyset(&set);
// set title = "master process" + argv[0] + argv[1] + ...
size = sizeof(master_process);
for (i = 0; i < ngx_argc; i++) {
size += ngx_strlen(ngx_argv[i]) + 1;
}
title = ngx_pnalloc(cycle->pool, size);
p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
for (i = 0; i < ngx_argc; i++) {
*p++ = ' ';
p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
}
ngx_setproctitle(title);
// Start workers and cache_manager
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_new_binary = 0;
delay = 0;
sigio = 0;
live = 1;
for ( ;; ) {
if (delay) {
if (ngx_sigalrm) {
sigio = 0;
delay *= 2;
ngx_sigalrm = 0;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"termination cycle: %d", delay);
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = 0;
itv.it_value.tv_sec = delay / 1000;
itv.it_value.tv_usec = (delay % 1000 ) * 1000;
if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setitimer() failed");
}
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");
// sigsuspend() temporarily replaces the signal mask of the calling
// process with the mask given by mask and then suspends the process
// until delivery of a signal whose action is to invoke a
// signal handler or to terminate a process.
sigsuspend(&set);
ngx_time_update();
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"wake up, sigio %i", sigio);
if (ngx_reap) {
ngx_reap = 0;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");
live = ngx_reap_children(cycle);
}
if (!live && (ngx_terminate || ngx_quit)) {
ngx_master_process_exit(cycle);
}
// on SIGINT set ngx_terminate = 1
if (ngx_terminate) {
if (delay == 0) {
delay = 50;
}
if (sigio) {
sigio--;
continue;
}
sigio = ccf->worker_processes + 2 /* cache processes */;
if (delay > 1000) {
ngx_signal_worker_processes(cycle, SIGKILL);
} else {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_TERMINATE_SIGNAL));
}
continue;
}
if (ngx_quit) {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
ls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
if (ngx_close_socket(ls[n].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[n].addr_text);
}
}
cycle->listening.nelts = 0;
continue;
}
if (ngx_reconfigure) {
ngx_reconfigure = 0;
if (ngx_new_binary) {
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_noaccepting = 0;
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_JUST_RESPAWN);
ngx_start_cache_manager_processes(cycle, 1);
// Nginx won't guarantee the new workers will be ready to accept
// new connections before sending shutdown signals to old workers.
// If the new works takes more than 100ms to startup, then there is
// a risk that the old workers are shutdown but new workers are still
// not ready, as a result, new connections will be pending until a new
// worker is ready to handle.
/* allow new processes to start */
ngx_msleep(100);
live = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
if (ngx_restart) {
ngx_restart = 0;
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
live = 1;
}
if (ngx_reopen) {
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, ccf->user);
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_REOPEN_SIGNAL));
}
if (ngx_change_binary) {
ngx_change_binary = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
}
if (ngx_noaccept) {
ngx_noaccept = 0;
ngx_noaccepting = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
}
}
//1.时间、正则、错误日志、ssl等初始化
//2.读入命令行参数
//3.OS相关初始化
//4.读入并解析配置
//5.核心模块初始化
//6.创建各种临时文件和目录
//7.创建共享内存
//8.打开listen的端口
//9.所有模块初始化
//10.启动worker进程
int ngx_cdecl //ngx_cdecl宏用于显式声明应使用的调用约定，在跨平台移植时有用，在linux版本的nginx程序中，该宏被定义为空
main(int argc, char *const *argv)
{
ngx_int_t i;
ngx_log_t *log; //保存日志结构
ngx_cycle_t *cycle, init_cycle; //初始化时的主结构体，在平滑升级服务器时，init_cycle负责升级前的信息,cycle负责升级后的信息
ngx_core_conf_t *ccf; //保存配置上下文
#if (NGX_FREEBSD)
ngx_debug_init(); //ngx_debug_init在FreeBSD和MacOSX平台有执行
#endif
//ngx_strerror_init 用于初始化nginx服务器自定义的标准错误输出列表 ready the ngx_sys_errlist
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
//获取参数和配置参数，比如命令是nginx -v 那么ngx_show_version就设置为1
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {//没有解析到 -v 不执行
ngx_write_stderr("nginx version: " NGINX_VER NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvVtq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -V : show version and configure options then exit"
NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
ngx_write_stderr(
#ifdef NGX_COMPILER
"built by " NGX_COMPILER NGX_LINEFEED
#endif
#if (NGX_SSL) //如果支持SSL
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
"TLS SNI support enabled" NGX_LINEFEED
#else
"TLS SNI support disabled" NGX_LINEFEED
#endif
#endif
"configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
//判断是否对nginx配置文件进行语法检查
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
//初始化nginx环境的当前时间
ngx_time_init();
#if (NGX_PCRE) //支持正则表达式
ngx_regex_init();//ngx_regex_malloc.c
#endif
//master pid， 获取当前进程ID
ngx_pid = ngx_getpid();
// 初始化日志，如打开日志文件//log = ngx_log_t 里面的ngx_open_file_t *file;
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log); //是否开启了ssl，如果开启在这里进行初始化
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
//内存管理初始化
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
// 为cycle创建一个1024B的内存池
init_cycle.pool = ngx_create_pool(1024, log);//分配的size 要减去ngx_pool_t结构体自身的内存所占大小
if (init_cycle.pool == NULL) {
return 1;
}
// 保存参数到全局变量中
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {//ngx_argv
return 1;
}
// 初始化init_cycle中的一些如: conf_file，prefix，conf_prefix等字段
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
// 初始化系统相关变量，如内存页面大小ngx_pagesize,ngx_cacheline_size,最大连接数ngx_max_sockets等
if (ngx_os_init(log) != NGX_OK) { //ngx_posix_init.c 这个ngx_os_init在不同操作系统调用不同的函数，根据系统参数来优化配置
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
// 初始化CRC表，提高效率，以后就不用计算了，直接用
if (ngx_crc32_table_init() != NGX_OK) {//src/core/ngx_crc32.c:111
return 1;
}
// 继承sockets,继承来的socket将会放到init_cycle的listening数组
//继承的原因：在nginx服务器升级的情况下，保证web服务的平滑过渡，新的nginx能够继承旧nginx打开的socket
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {// src/core/nginx.c:442
return 1;
}
// 计算模块个数，并且设置各个模块顺序（索引）
ngx_max_module = 0;// ngx_command_t : http://book.51cto.com/art/201312/420058.htm *commands ngx_module_s :http://my.oschina.net/showcolors/blog/101169
for (i = 0; ngx_modules[i]; i++) { // 这里面的ngx_modules会有非常多的模块，[ngx_core_module,ngx_errlog_module,ngx_conf_moduel]
ngx_modules[i]->index = ngx_max_module++;// p ngx_modules[0]->commands->name
}
// 对ngx_cycle结构进行初始化,这里是nginx启动核心之处！
cycle = ngx_init_cycle(&init_cycle);//ngx_cycle.c 44
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
return 0;
}
// 检查是否有设置信号处理，如有，进入ngx_signal_process处理
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) { //如果是daemon模式，本进程变为守护进程
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
// 创建进程记录文件
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (cycle->log->file->fd != ngx_stderr) {
if (ngx_set_stderr(cycle->log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
ngx_set_stderr_n " failed");
return 1;
}
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
//下面调用ngx_single_process_cycle或者ngx_master_process_cycle来启动nginx
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle); //单进程，基本很少用single模式
} else {
ngx_master_process_cycle(cycle); //多进程，master进程进入这个，这个函数在不同操作系统有不同实现。
}
return 0;
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_buf_t *b;
ngx_log_t *log;
ngx_uint_t i;
ngx_cycle_t *cycle, init_cycle;
ngx_conf_dump_t *cd;
ngx_core_conf_t *ccf;
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvVtTq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -V : show version and configure options then exit"
NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED
" -T : test configuration, dump it and exit"
NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
#ifdef NGX_COMPILER
ngx_write_stderr("built by " NGX_COMPILER NGX_LINEFEED);
#endif
#if (NGX_SSL)
if (SSLeay() == SSLEAY_VERSION_NUMBER) {
ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
NGX_LINEFEED);
} else {
ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
" (running with ");
ngx_write_stderr((char *) (uintptr_t)
SSLeay_version(SSLEAY_VERSION));
ngx_write_stderr(")" NGX_LINEFEED);
}
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
ngx_write_stderr("TLS SNI support enabled" NGX_LINEFEED);
#else
ngx_write_stderr("TLS SNI support disabled" NGX_LINEFEED);
#endif
#endif
ngx_write_stderr("configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
if (ngx_dump_config) {
cd = cycle->config_dump.elts;
for (i = 0; i < cycle->config_dump.nelts; i++) {
ngx_write_stdout("# configuration file ");
(void) ngx_write_fd(ngx_stdout, cd[i].name.data,
cd[i].name.len);
ngx_write_stdout(":" NGX_LINEFEED);
b = cd[i].buffer;
(void) ngx_write_fd(ngx_stdout, b->pos, b->last - b->pos);
ngx_write_stdout(NGX_LINEFEED);
}
}
return 0;
}
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
zlog_init_conf_path();
if (zlog_load_conf(zlog_init))
{
return 1;
}
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
return 1;
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
struct sigaction act;
memset(&act, 0, sizeof(struct sigaction));
sigemptyset(&act.sa_mask);
act.sa_sigaction = sig_user1_handler;
act.sa_flags = SA_SIGINFO;
if(-1 == sigaction(SIGUSR1, &act, NULL)) {
return 1;
}
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle);
} else {
if (NGX_OK != ngx_before_master_cycle(cycle))
{
return 1;
}
ngx_master_process_cycle(cycle);
}
return 0;
}
// nginx启动的入口函数
// 相关文件ngx_process_cycle.c/ngx_posix_init.c/ngx_process.c
// 设置重要的指针volatile ngx_cycle_t *ngx_cycle;
//
// 1)解析命令行参数,显示帮助信息
// 2)初始化操作系统调用接口函数ngx_os_io = ngx_linux_io;
// 3)根据命令行参数等建立一个基本的cycle
// 4)初始化模块数组ngx_modules
// 5)核心操作，调用ngx_init_cycle创建进程使用的cycle,解析配置文件,启动监听端口
// 6)启动单进程或多进程
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_buf_t *b;
ngx_log_t *log;
ngx_uint_t i;
ngx_cycle_t *cycle, init_cycle; //cycle结构体
ngx_conf_dump_t *cd;
ngx_core_conf_t *ccf; //获得ngx_core_module的配置结构体
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
// 解析命令行参数, 本文件内查找ngx_get_options
// 设置ngx_show_version/ngx_show_help等变量
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
// 1.9.x改到ngx_show_version_info()
if (ngx_show_version) {
ngx_show_version_info();
// 1.9.x ngx_show_version_info()结束
if (!ngx_test_config) { //如果是-t参数，那么接下来要走流程检查配置但不启动
return 0;
}
}
// 在ngx_os_init函数里设置（os/unix/ngx_posix_init.c）
// 使用系统调用getrlimit(RLIMIT_NOFILE, &rlmt)
// 是nginx能够打开的最多描述数量，但似乎并没有使用
/* TODO */ ngx_max_sockets = -1;
// ngx_times.c,初始化各个cache时间变量
// 调用ngx_time_update()，得到当前的时间
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init(); // 正则表达式库初始化
#endif
// 定义在os/unix/ngx_process_cycle.c : ngx_pid_t ngx_pid;
// ngx_process.h : #define ngx_getpid getpid
// 获取当前进程也就是master进程的pid
// 如果是master/worker，会fork出新的子进程，见os/unix/ngx_daemon.c
ngx_pid = ngx_getpid();
// 初始化log
// ngx_prefix是-p后的参数，即nginx的工作目录
// 默认是NGX_CONF_PREFIX，即/usr/local/nginx
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
// 设置最开始的cycle
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
// 定义在ngx_cycle.c,
// volatile ngx_cycle_t *ngx_cycle;
// nginx生命周期使用的超重要对象
// ngx_cycle指针指向第一个cycle结构体
ngx_cycle = &init_cycle;
//创建cycle使用的内存池，用于之后所有的内存分配，必须成功
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
// 分配内存，拷贝参数，没有使用内存池
// 拷贝到全局变量ngx_argc/ngx.argv
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
// 设置cycle->prefix/cycle->conf_prefix等成员
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
// os/unix/ngx_posix_init.c
// 初始化ngx_os_io结构体，设置基本的收发函数
// 基本的页大小,ngx_pagesize = getpagesize()
// 最多描述符数量，ngx_max_sockets
// 初始化随机数
// ngx_os_io = ngx_linux_io;重要的操作,设置为linux的接口函数
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
// 初始化用于crc32计算的表，在ngx_crc32.c
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
// 检查NGINX环境变量，获取之前监听的socket
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
// 开始计算所有的静态模块数量
// ngx_modules是nginx模块数组，存储所有的模块指针，由make生成在objs/ngx_modules.c
// 这里赋值每个模块的index成员
// ngx_modules_n保存了最后一个可用的序号
// ngx_max_module是模块数量的上限
if (ngx_preinit_modules() != NGX_OK) {
return 1;
}
// ngx_cycle.c
// 初始化cycle,800多行
// 由之前最基本的init_cycle产生出真正使用的cycle
// 解析配置文件，配置所有的模块
// 创建共享内存，打开文件，监听配置的端口
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
// 如果用了-t参数要测试配置，在这里就结束了
// 定义在ngx_cycle.c
if (ngx_test_config) {
//非安静模式，输出测试信息
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
// 1.10, dump整个配置文件
if (ngx_dump_config) {
cd = cycle->config_dump.elts;
for (i = 0; i < cycle->config_dump.nelts; i++) {
ngx_write_stdout("# configuration file ");
(void) ngx_write_fd(ngx_stdout, cd[i].name.data,
cd[i].name.len);
ngx_write_stdout(":" NGX_LINEFEED);
b = cd[i].buffer;
(void) ngx_write_fd(ngx_stdout, b->pos, b->last - b->pos);
ngx_write_stdout(NGX_LINEFEED);
}
}
return 0;
}
// 如果用了-s参数，那么就要发送reload/stop等信号，然后结束
if (ngx_signal) {
// ngx_cycle.c
// 最后调用os/unix/ngx_process.c里的函数ngx_os_signal_process()
return ngx_signal_process(cycle, ngx_signal);
}
// ngx_posix_init.c
// 使用NGX_LOG_NOTICE记录操作系统的一些信息,通常不会显示
ngx_os_status(cycle->log);
// 定义在ngx_cycle.c,
// volatile ngx_cycle_t *ngx_cycle;
// nginx生命周期使用的超重要对象
ngx_cycle = cycle;
// 检查core模块的配置
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
// master on且单进程
// 如果master_process off那么就不是master进程
// ngx_process定义在os/unix/ngx_process_cycle.c
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
// 设置为master进程状态
ngx_process = NGX_PROCESS_MASTER;
}
// unix/linux将进程守护进程化
#if !(NGX_WIN32)
// os/unix/ngx_process.c
// 使用signals数组，初始化信号处理handler
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
// 守护进程
if (!ngx_inherited && ccf->daemon) {
// os/unix/ngx_daemon.c
// 经典的daemon操作，使用fork
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
// ngx_cycle.c
// 把ngx_pid字符串化，写入pid文件
// 在daemon后，此时的pid是真正的master进程pid
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
return 1;
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
// 启动单进程或者master/worker多进程，内部会调用fork
// 子进程完全复制父进程的cycle，包括打开的文件、共享内存、监听的端口
if (ngx_process == NGX_PROCESS_SINGLE) {
// 如果master_process off那么就不是master进程
// ngx_process_cycle.c
ngx_single_process_cycle(cycle);
} else {
// ngx_process_cycle.c
// 启动worker进程，数量由配置决定，即worker_processes指令
// 核心操作是sigsuspend，暂时挂起进程，不占用CPU，只有收到信号时才被唤醒
ngx_master_process_cycle(cycle);
}
// 只有退出无限循环才会走到这里，进程结束
return 0;
}
/*
* __cdecl表示C语言默认的函数调用方法，即所有参数从右到左依次入栈，这些参数有调用者负责清除，被调用函数不会要求
* 调用者传递多少参数，调用者传递过多或过少的参数都不会引起编译错误。
*/
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_buf_t *b;
ngx_log_t *log;
ngx_uint_t i;
ngx_cycle_t *cycle, init_cycle;
ngx_conf_dump_t *cd;
ngx_core_conf_t *ccf;
ngx_debug_init(); //设置全局变量ngx_debug_malloc
/*初始化系统错误码对应的描述性字符串*/
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
/*ngx_get_options()函数用于解析命令行参数，并设置命令行参数相应的标志位*/
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
/*根据ngx_get_options()函数中设置的标志位打印相关信息到标准输出上*/
if (ngx_show_version) {
ngx_show_version_info();
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
/*初始化并更新nginx内核使用的时间*/
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
/*获取master进程ID*/
ngx_pid = ngx_getpid();
/*初始化全局错误日志对象ngx_log及前缀ngx_prefix*/
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
/*为进程唯一核心结构体ngx_cycle_t的创建内存池*/
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
/*保存命令行参数*/
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
/*ngx_process_options()用于初始化ngx_cycle的prefix, conf_prefix, conf_file, conf_param等*/
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
/*对Nginx内核中用到的一些和操作系统相关性大的全局变量进行初始化*/
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
/*初始化循环冗余校验表，后续校验可以直接通过查表法*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
/*平滑升级时新版本master进程对旧版本master进程的监听句柄做继承处理*/
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
/*ngx_preinit_modules()初始化模块的一些信息和部分相关全局变量*/
if (ngx_preinit_modules() != NGX_OK) {
return 1;
}
/*初始化全局唯一的ngx_cycle_t*/
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
if (ngx_dump_config) {
cd = cycle->config_dump.elts;
for (i = 0; i < cycle->config_dump.nelts; i++) {
ngx_write_stdout("# configuration file ");
(void) ngx_write_fd(ngx_stdout, cd[i].name.data,
cd[i].name.len);
ngx_write_stdout(":" NGX_LINEFEED);
b = cd[i].buffer;
(void) ngx_write_fd(ngx_stdout, b->pos, b->last - b->pos);
ngx_write_stdout(NGX_LINEFEED);
}
}
return 0;
}
/*"nginx -s xxx"*/
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
/*初始化信号*/
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
/*创建pidfile，并写入当前进程id*/
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
return 1;
}
/*关闭日志文件流*/
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
/*单进程模式运行*/
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle);
} else {
/*以一个master进程多个woker进程运行*/
ngx_master_process_cycle(cycle);
}
return 0;
}
int ngx_cdecl
main(int argc, char *const *argv)
{
char *p;
ssize_t n;
ngx_int_t i;
ngx_log_t *log;
ngx_cycle_t *cycle, init_cycle;
ngx_core_conf_t *ccf;
#if (NGX_FREEBSD)
ngx_debug_init();
#endif
/* TODO */ ngx_max_sockets = -1;
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
log = ngx_log_init();
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/* init_cycle->log is required for signal handlers and ngx_getopt() */
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
if (ngx_getopt(&init_cycle, argc, ngx_argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
p = "nginx version: " NGINX_VER CRLF;
n = sizeof("nginx version: " NGINX_VER CRLF) - 1;
if (ngx_write_fd(ngx_stderr_fileno, p, n) != n) {
return 1;
}
if (ngx_show_configure) {
#ifdef NGX_COMPILER
p = "built by " NGX_COMPILER CRLF;
n = sizeof("built by " NGX_COMPILER CRLF) - 1;
if (ngx_write_fd(ngx_stderr_fileno, p, n) != n) {
return 1;
}
#endif
p = "configure arguments:" NGX_CONFIGURE CRLF;
n = sizeof("configure arguments:" NGX_CONFIGURE CRLF) - 1;
if (ngx_write_fd(ngx_stderr_fileno, p, n) != n) {
return 1;
}
}
if (!ngx_test_config) {
return 0;
}
}
if (ngx_test_config) {
log->log_level = NGX_LOG_INFO;
}
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_error(NGX_LOG_EMERG, log, 0,
"the configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
ngx_log_error(NGX_LOG_INFO, log, 0,
"the configuration file %s was tested successfully",
cycle->conf_file.data);
return 0;
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
ngx_process = ccf->master ? NGX_PROCESS_MASTER : NGX_PROCESS_SINGLE;
#if (NGX_WIN32)
#if 0
TODO:
if (ccf->run_as_service) {
if (ngx_service(cycle->log) != NGX_OK) {
return 1;
}
return 0;
}
#endif
#else
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
#endif
if (ngx_process == NGX_PROCESS_MASTER) {
ngx_master_process_cycle(cycle);
} else {
ngx_single_process_cycle(cycle);
}
return 0;
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_int_t i;
ngx_log_t *log;
ngx_cycle_t *cycle, init_cycle;
ngx_core_conf_t *ccf;
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
//获取参数和配置参数，比如命令是nginx -v 那么ngx_show_version就设置为1
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_write_stderr("nginx version: " NGINX_VER NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvVtq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -V : show version and configure options then exit"
NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
ngx_write_stderr(
#ifdef NGX_COMPILER
"built by " NGX_COMPILER NGX_LINEFEED
#endif
#if (NGX_SSL)
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
"TLS SNI support enabled" NGX_LINEFEED
#else
"TLS SNI support disabled" NGX_LINEFEED
#endif
#endif
"configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
//初始化nginx环境的当前时间
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
//master pid， 获取当前进程ID
ngx_pid = ngx_getpid();
// 初始化日志，如打开日志文件
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log); //是否开启了ssl，如果开启在这里进行初始化
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
// 为cycle创建一个1024B的内存池
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
// 将命令行参数保存到ngx_os_argv、ngx_argc以及ngx_argv这几个全局的变量中。
// 这算是一个备份存储，方便以后master进程做热代码替换之用。
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
// 初始化init_cycle中的一些如: conf_file，prefix，conf_prefix等字段
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
// 完成操作系统的一些信息获取，如内存页面大小、系统限制资源,ngx_pagesize,ngx_cacheline_size,最大连接数ngx_max_sockets等
// 所有的这些资源都将会被保存在对应的全局变量中，因此后续访问将会很便利。
if (ngx_os_init(log) != NGX_OK) {// 这个ngx_os_init在不同操作系统调用不同的函数
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
// 初始化一个做循环冗余校验的表，由此可以看出后续的循环冗余校验将采用高效的查表法。
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
// 通过环境变量NGINX完成socket的继承，继承来的socket将会放到init_cycle的listening数组中。
// 在NGINX环境变量中，每个socket中间用冒号或分号隔开。完成继承同时设置全局变量ngx_inherited为1。
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
// 计算模块个数，并且设置各个模块顺序（索引）
// 这里面的ngx_modules会有非常多的模块，编译后在objs下面会生成一个ngx_modules.c文件，里边列出了所有使用的模块
// 默认有44个模块
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
// 对ngx_cycle结构进行初始化,这里是nginx启动核心之处, 会将很多东西放在init_cycle中
// 详细见ngx_cycle.c中的 ngx_init_cycle方法
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
return 0;
}
// 检查是否有设置信号处理，如有，进入ngx_signal_process处理
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
// 获取核心模块的配置信息
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
// 注册一堆信号处理程序，需要注册的信号及相应的信号处理函数被放在一个类型为ngx_signal_t的数组signals中。
// 数组定义在src/os/unix/ngx_process.c中。ngx_signal_t结构类型定义了信号值，信号名字，信号对应动作名以及信号处理函数。
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
// ngx_daemon肯定就是用来实现守护进程的函数了, 有需要写server程序的，可以直接copy这段代码实现守护进程。
// 代码实现位于 ./src/os/unix/ngx_daemon.c
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
// 玩过Nginx的人都知道，Nginx启动后有一个记录进程id的文件，这个文件里面就一个pid。
// 原来这个pid就是在这个地方记录下来的。查看ngx_create_pidfile函数可以看到这样的一行代码
// 其中第一个参数为pid文件名称， 从核心配置文件中读取到的
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (cycle->log->file->fd != ngx_stderr) {
if (ngx_set_stderr(cycle->log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
ngx_set_stderr_n " failed");
return 1;
}
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle); //单进程
} else {
ngx_master_process_cycle(cycle); //多进程，master进程进入这个，这个函数在不同操作系统有不同实现。
}
return 0;
}
// main()函数里调用，启动worker进程
// 监听信号
// 核心操作是sigsuspend，暂时挂起进程，不占用CPU，只有收到信号时才被唤醒
void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
char *title;
u_char *p;
size_t size;
ngx_int_t i;
ngx_uint_t n, sigio;
sigset_t set;
struct itimerval itv;
ngx_uint_t live;
ngx_msec_t delay;
ngx_listening_t *ls;
ngx_core_conf_t *ccf;
// 添加master进程关注的信号
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGALRM);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGINT);
sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigprocmask() failed");
}
sigemptyset(&set);
// static u_char master_process[] = "master process";
// 计算master进程的名字
size = sizeof(master_process);
// 加上命令行参数，注意使用的是nginx拷贝后的参数
for (i = 0; i < ngx_argc; i++) {
size += ngx_strlen(ngx_argv[i]) + 1;
}
// 分配名字的内存
title = ngx_pnalloc(cycle->pool, size);
if (title == NULL) {
/* fatal */
exit(2);
}
// 拷贝字符串
p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
for (i = 0; i < ngx_argc; i++) {
*p++ = ' ';
p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
}
// 设置进程名
ngx_setproctitle(title);
// 取core模块配置
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
// 启动worker进程，数量由配置决定，即worker_processes指令
// #define NGX_PROCESS_RESPAWN -3
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
// cache进程
ngx_start_cache_manager_processes(cycle, 0);
ngx_new_binary = 0;
delay = 0; //延时的计数器
sigio = 0;
live = 1; //是否有存活的子进程
// master进程的无限循环，只处理信号
// 主要调用ngx_signal_worker_processes()发送信号
// ngx_start_worker_processes()产生新子进程
for ( ;; ) {
// 延时等待子进程关闭，每次进入加倍等待
if (delay) {
if (ngx_sigalrm) {
sigio = 0;
delay *= 2; //延时加倍
ngx_sigalrm = 0;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"termination cycle: %d", delay);
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = 0;
itv.it_value.tv_sec = delay / 1000;
itv.it_value.tv_usec = (delay % 1000 ) * 1000;
// 系统调用，设置发送SIGALRM的时间间隔
if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setitimer() failed");
}
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");
// 核心操作是sigsuspend，暂时挂起进程，不占用CPU，只有收到信号时才被唤醒
// 收到SIGALRM就检查子进程是否都已经处理完了
sigsuspend(&set);
// 更新一下时间
ngx_time_update();
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"wake up, sigio %i", sigio);
// 子进程可能发生了意外结束
// 在os/unix/ngx_process.c ngx_signal_handler()里设置
if (ngx_reap) {
ngx_reap = 0;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");
// 重新产生子进程
live = ngx_reap_children(cycle);
}
// 无存活子进程且收到stop/quit信号
if (!live && (ngx_terminate || ngx_quit)) {
// 删除pid，模块清理，关闭监听端口
// 内部直接exit(0)退出
ngx_master_process_exit(cycle);
}
// 收到了-s stop，停止进程
if (ngx_terminate) {
// 延时等待子进程关闭
if (delay == 0) {
delay = 50;
}
if (sigio) {
sigio--;
continue;
}
sigio = ccf->worker_processes + 2 /* cache processes */;
if (delay > 1000) {
// 超时太多，直接发送SIGKILL杀死进程
// master进程调用，遍历ngx_processes数组，用kill发送信号
ngx_signal_worker_processes(cycle, SIGKILL);
} else {
// master进程调用，遍历ngx_processes数组，用kill发送信号
// 走到worker进程的ngx_signal_handler()
// 然后再是ngx_worker_process_cycle()的ngx_terminate
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_TERMINATE_SIGNAL));
}
// 等待SIGALRM信号，检查子进程是否都结束
continue;
}
// 收到了-s quit，关闭监听端口后再停止进程（优雅关闭）
if (ngx_quit) {
// master进程调用，遍历ngx_processes数组，用kill发送信号
// 走到worker进程的ngx_signal_handler()
// 然后再是ngx_worker_process_cycle()的ngx_quit
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
// 关闭所有监听端口
ls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
if (ngx_close_socket(ls[n].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[n].addr_text);
}
}
cycle->listening.nelts = 0;
continue;
}
// 收到了-s reload重新配置
if (ngx_reconfigure) {
ngx_reconfigure = 0;
// 启动新的nginx二进制
if (ngx_new_binary) {
// 启动worker进程，数量由配置决定，即worker_processes指令
// 调用时传递的是#define NGX_PROCESS_RESPAWN -3
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_noaccepting = 0;
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
// nginx可执行程序不变，以当前cycle重新初始化
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
// 启动worker进程，数量由配置决定，即worker_processes指令
// 调用时传递的是#define NGX_PROCESS_JUST_RESPAWN -2
// 这样新启动的进程不会发送shutdown信号
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_JUST_RESPAWN);
ngx_start_cache_manager_processes(cycle, 1);
/* allow new processes to start */
// 阻塞等待100毫秒
ngx_msleep(100);
// 设置进程存活标志
live = 1;
// 关闭原来的worker进程
// 新启动的进程不会发送shutdown信号
// master进程调用，遍历ngx_processes数组，用kill发送信号
// 走到worker进程的ngx_signal_handler()
// 然后再是ngx_worker_process_cycle()的ngx_quit
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
if (ngx_restart) {
ngx_restart = 0;
// 启动worker进程，数量由配置决定，即worker_processes指令
// 调用时传递的是#define NGX_PROCESS_RESPAWN -3
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
// 设置进程存活标志
live = 1;
}
if (ngx_reopen) {
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, ccf->user);
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_REOPEN_SIGNAL));
}
if (ngx_change_binary) {
ngx_change_binary = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
}
if (ngx_noaccept) {
ngx_noaccept = 0;
ngx_noaccepting = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
} //master进程无限循环结束
}
// 启动后master进程在这个函数进入死循环
void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
char *title;
u_char *p;
size_t size;
ngx_int_t i;
ngx_uint_t n, sigio;
sigset_t set;
struct itimerval itv;
ngx_uint_t live;
ngx_msec_t delay;
ngx_listening_t *ls;
ngx_core_conf_t *ccf;
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGALRM);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGINT);
sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));
// 让master进程只有在sigsuspend()里才会捕捉参数set里的信号。
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigprocmask() failed");
}
sigemptyset(&set);
// 设置ps命令显示的进程标题
size = sizeof(master_process);
for (i = 0; i < ngx_argc; i++) {
size += ngx_strlen(ngx_argv[i]) + 1;
}
title = ngx_pnalloc(cycle->pool, size);
p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
for (i = 0; i < ngx_argc; i++) {
*p++ = ' ';
p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
}
ngx_setproctitle(title);
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
// 启动worker进程
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
// 配置文件配置了相关功能时打开cache manager或cache loader进程,
ngx_start_cache_manager_processes(cycle, 0);
ngx_new_binary = 0;
delay = 0;
sigio = 0;
live = 1;
for ( ;; ) {
if (delay) {
// 收到退出信号后会使用这个分支，
// 作用是定时检查是否还有活跃子进程，如果没有就退出master进程
if (ngx_sigalrm) {
sigio = 0;
delay *= 2;
ngx_sigalrm = 0;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"termination cycle: %d", delay);
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = 0;
itv.it_value.tv_sec = delay / 1000;
itv.it_value.tv_usec = (delay % 1000 ) * 1000;
if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setitimer() failed");
}
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");
// 当没有收到信号时进程会在这个函数里休眠, 当收到信号后如果有信号处理函数先运行信号处理函数，
// 然后向下运行。
sigsuspend(&set);
// 更新记录当前时间的全局变量。
ngx_time_update();
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"wake up, sigio %i", sigio);
if (ngx_reap) {
// master进程的子进程结束时，master进程收到SIGCHLD信号后，ngx_reap被置1。
ngx_reap = 0;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");
live = ngx_reap_children(cycle);
}
if (!live && (ngx_terminate || ngx_quit)) {
// 收到退出信号且已经没有活跃子进程后便退出
ngx_master_process_exit(cycle);
}
if (ngx_terminate) {
// 收到SIGINT,SIGTERM信号后，直接关闭nginx,
// 首先给子进程发送关闭信号，1秒还没有关完就强制关闭所有子进程
if (delay == 0) {
delay = 50;
}
if (sigio) {
sigio--;
continue;
}
sigio = ccf->worker_processes + 2 /* cache processes */;
if (delay > 1000) {
ngx_signal_worker_processes(cycle, SIGKILL);
} else {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_TERMINATE_SIGNAL));
}
continue;
}
if (ngx_quit) {
// 收到SIGQUIT信号后，优雅关闭Nginx，
// 待所有worker进程将已经连接的请求处理完后在退出
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
ls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
if (ngx_close_socket(ls[n].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[n].addr_text);
}
}
cycle->listening.nelts = 0;
continue;
}
if (ngx_reconfigure) {
// 收到SIGHUP信号后，ngx_reconfigure在信号处理函数中被置1，执行让新配置文件生效的操作。
ngx_reconfigure = 0;
if (ngx_new_binary) {
// 在不重新载入配置文件的情况下启动工作进程。
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_noaccepting = 0;
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_JUST_RESPAWN);
ngx_start_cache_manager_processes(cycle, 1);
/* allow new processes to start */
ngx_msleep(100);
live = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
if (ngx_restart) {
// 好像是平滑升级时，新起的nginx意外退出了，要在把之前nginx的工作进程在重新启动
ngx_restart = 0;
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
live = 1;
}
if (ngx_reopen) {
// 重新打开日志文件
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, ccf->user);
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_REOPEN_SIGNAL));
}
if (ngx_change_binary) {
// 启动新的nignx,使新旧nginx同时工作
ngx_change_binary = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
}
if (ngx_noaccept) {
// 收到sigwinch信号后优雅关闭所有子进程
ngx_noaccept = 0;
ngx_noaccepting = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
}
}
//1.时间、正则、错误日志、ssl等初始化
//2.读入命令行参数
//3.OS相关初始化
//4.读入并解析配置
//5.核心模块初始化
//6.创建各种临时文件和目录
//7.创建共享内存
//8.打开listen的端口
//9.所有模块初始化
//10.启动worker进程
//全书内容可以在http://book.2cto.com/201304/19606.html中查看，可以直接复制注释
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_buf_t *b;
ngx_log_t *log;
ngx_uint_t i;
ngx_cycle_t *cycle, init_cycle;
ngx_conf_dump_t *cd;
ngx_core_conf_t *ccf;
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
//获取参数和配置参数，比如命令是nginx -v 那么ngx_show_version就设置为1
if (ngx_get_options(argc, argv) != NGX_OK) { //解析命令参数
return 1;
}
if (ngx_show_version) {
ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvVtTq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -V : show version and configure options then exit" //除了version外还可以显示操作系统和configure阶段等相关信息
NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED //不启动nginx进程，只是测试配置文件是否有错误
" -T : test configuration, dump it and exit"
NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED //通过-t测试配置文件是否错误的时候,nginx -t -q可以把error级别以下的日志不输出的屏幕
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED //指定安装目录
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED //指定配置文件
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
#ifdef NGX_COMPILER
ngx_write_stderr("built by " NGX_COMPILER NGX_LINEFEED);
#endif
#if (NGX_SSL)
if (SSLeay() == SSLEAY_VERSION_NUMBER) {
ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
NGX_LINEFEED);
} else {
ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
" (running with ");
ngx_write_stderr((char *) (uintptr_t)
SSLeay_version(SSLEAY_VERSION));
ngx_write_stderr(")" NGX_LINEFEED);
}
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
ngx_write_stderr("TLS SNI support enabled" NGX_LINEFEED);
#else
ngx_write_stderr("TLS SNI support disabled" NGX_LINEFEED);
#endif
#endif
ngx_write_stderr("configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
ngx_time_init(); //初始化nginx环境的当前时间
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
/*
主进程启动的时候，此时还没有读取配置文件，即没有指定日志打印在哪里。nginx这时候虽然可以将一些出错内容或者结果输到标准输出，但是如果要记录一些系统初始化情况，
socket监听状况，还是需要写到日志文件中去的。在nginx的main函数中，首先会调用ngx_log_init 函数，默认日志文件为：安装路径/logs/error.log，如果这个文件没有权限访问的话，
会直接报错退出。在mian函数结尾处，在ngx_master_process_cycle函数调用之前，会close掉这个日志文件。
*/
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
if (ngx_dump_config) {
cd = cycle->config_dump.elts;
for (i = 0; i < cycle->config_dump.nelts; i++) {
ngx_write_stdout("# configuration file ");
(void) ngx_write_fd(ngx_stdout, cd[i].name.data,
cd[i].name.len);
ngx_write_stdout(":" NGX_LINEFEED);
b = cd[i].buffer;
(void) ngx_write_fd(ngx_stdout, b->pos, b->last - b->pos);
ngx_write_stdout(NGX_LINEFEED);
}
}
return 0;
}
/*
如果hginx.conf中配置为单进程工作模式，这时将会调用ngx_single_process_cycle方法进入单迸程工作模式。
*/
if (ngx_signal) { //加了-S参数
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) { //在这里会把进程模式设置为MASTER模式
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
return 1;
}
if (log->file->fd != ngx_stderr) {
//前面的log = ngx_log_init(ngx_prefix);
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
if (ngx_process == NGX_PROCESS_SINGLE) { //如果配置的是单进程工作模式，好像不会走到这里
ngx_single_process_cycle(cycle);
} else { //一般都是走到这里，master方式
ngx_master_process_cycle(cycle);
}
return 0;
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_int_t i;
ngx_log_t *log;
ngx_cycle_t *cycle, init_cycle;
ngx_core_conf_t *ccf;
/* 与OS相关的debug宏, linux平台下它什么也不做 */
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvVtq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -V : show version and configure options then exit"
NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
#ifdef NGX_COMPILER
ngx_write_stderr("built by " NGX_COMPILER NGX_LINEFEED);
#endif
#if (NGX_SSL)
if (SSLeay() == SSLEAY_VERSION_NUMBER) {
ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
NGX_LINEFEED);
} else {
ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
" (running with ");
ngx_write_stderr((char *) (uintptr_t)
SSLeay_version(SSLEAY_VERSION));
ngx_write_stderr(")" NGX_LINEFEED);
}
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
ngx_write_stderr("TLS SNI support enabled" NGX_LINEFEED);
#else
ngx_write_stderr("TLS SNI support disabled" NGX_LINEFEED);
#endif
#endif
ngx_write_stderr("configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
/* 初始化时间缓存 */
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
/* 执行热替换时,new master 从环境变量继承old master的监听套接口 */
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
/* 模块在ngx_modules数组中的索引填入 index字段 */
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
/* 创建一个新的ngx_cycle_t */
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
return 0;
}
/* 信号发生器模式 */
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
/* master模式 */
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER; /* 设置当前进程为master进程 */
}
#if !(NGX_WIN32)
/* 信号处理初始化 */
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
return 1;
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle);
} else {
ngx_master_process_cycle(cycle);
}
return 0;
}
void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
char *title;
u_char *p;
size_t size;
ngx_int_t i;
ngx_uint_t n, sigio;
sigset_t set;
struct itimerval itv;
ngx_uint_t live;
ngx_msec_t delay;
ngx_listening_t *ls;
ngx_core_conf_t *ccf;
struct rlimit rlmt;
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGALRM);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGINT);
sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigprocmask() failed");
}
sigemptyset(&set);
size = sizeof(master_process);
for (i = 0; i < ngx_argc; i++) {
size += ngx_strlen(ngx_argv[i]) + 1;
}
title = ngx_pnalloc(cycle->pool, size);
p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
for (i = 0; i < ngx_argc; i++) {
*p++ = ' ';
p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
}
ngx_setproctitle(title);
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
/* The directives such as "user", "rlimit_core", etc. should also be
* effective on master process. Changed by Zimbra
*/
if (ccf->rlimit_nofile != NGX_CONF_UNSET) {
rlmt.rlim_cur = (rlim_t) ccf->rlimit_nofile;
rlmt.rlim_max = (rlim_t) ccf->rlimit_nofile;
if (setrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setrlimit(RLIMIT_NOFILE, %i) failed",
ccf->rlimit_nofile);
}
}
if (ccf->rlimit_core != NGX_CONF_UNSET) {
rlmt.rlim_cur = (rlim_t) ccf->rlimit_core;
rlmt.rlim_max = (rlim_t) ccf->rlimit_core;
if (setrlimit(RLIMIT_CORE, &rlmt) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setrlimit(RLIMIT_CORE, %O) failed",
ccf->rlimit_core);
}
}
#ifdef RLIMIT_SIGPENDING
if (ccf->rlimit_sigpending != NGX_CONF_UNSET) {
rlmt.rlim_cur = (rlim_t) ccf->rlimit_sigpending;
rlmt.rlim_max = (rlim_t) ccf->rlimit_sigpending;
if (setrlimit(RLIMIT_SIGPENDING, &rlmt) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setrlimit(RLIMIT_SIGPENDING, %i) failed",
ccf->rlimit_sigpending);
}
}
#endif
if (geteuid() == 0) {
if (setgid(ccf->group) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"setgid(%d) failed", ccf->group);
/* fatal */
exit(2);
}
if (initgroups(ccf->username, ccf->group) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"initgroups(%s, %d) failed",
ccf->username, ccf->group);
}
if (setuid(ccf->user) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"setuid(%d) failed", ccf->user);
/* fatal */
exit(2);
}
}
/* end change by Zimbra */
ngx_start_cache_manager_processes(cycle, 0);
ngx_new_binary = 0;
delay = 0;
sigio = 0;
live = 1;
for ( ;; ) {
if (delay) {
if (ngx_sigalrm) {
sigio = 0;
delay *= 2;
ngx_sigalrm = 0;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"termination cycle: %d", delay);
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = 0;
itv.it_value.tv_sec = delay / 1000;
itv.it_value.tv_usec = (delay % 1000 ) * 1000;
if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setitimer() failed");
}
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");
sigsuspend(&set);
ngx_time_update();
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"wake up, sigio %i", sigio);
if (ngx_reap) {
ngx_reap = 0;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");
live = ngx_reap_children(cycle);
}
if (!live && (ngx_terminate || ngx_quit)) {
ngx_master_process_exit(cycle);
}
if (ngx_terminate) {
if (delay == 0) {
delay = 50;
}
if (sigio) {
sigio--;
continue;
}
sigio = ccf->worker_processes + 2 /* cache processes */;
if (delay > 1000) {
ngx_signal_worker_processes(cycle, SIGKILL);
} else {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_TERMINATE_SIGNAL));
}
continue;
}
if (ngx_quit) {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
ls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
if (ngx_close_socket(ls[n].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[n].addr_text);
}
}
cycle->listening.nelts = 0;
continue;
}
if (ngx_reconfigure) {
ngx_reconfigure = 0;
if (ngx_new_binary) {
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_noaccepting = 0;
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_JUST_RESPAWN);
ngx_start_cache_manager_processes(cycle, 1);
live = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
if (ngx_restart) {
ngx_restart = 0;
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
live = 1;
}
if (ngx_reopen) {
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, ccf->user);
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_REOPEN_SIGNAL));
}
if (ngx_change_binary) {
ngx_change_binary = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
}
if (ngx_noaccept) {
ngx_noaccept = 0;
ngx_noaccepting = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
}
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_buf_t *b;
ngx_log_t *log;
ngx_uint_t i;
ngx_cycle_t *cycle, init_cycle;
ngx_conf_dump_t *cd;
ngx_core_conf_t *ccf;
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_show_version_info();
if (!ngx_test_config) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle; // 将init_cycle赋值给全局变量ngx_cycle
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
/*
* 新版本master进程通过ngx_add_inherited_sockets方法由环境变量读取平滑升级信息，并对
* 旧版本Nginx服务监听的句柄做继承处理
*/
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
if (ngx_preinit_modules() != NGX_OK) {
return 1;
}
/* 重要
* 读取配置并初始化各个模块
*/
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
if (ngx_dump_config) {
cd = cycle->config_dump.elts;
for (i = 0; i < cycle->config_dump.nelts; i++) {
ngx_write_stdout("# configuration file ");
(void) ngx_write_fd(ngx_stdout, cd[i].name.data,
cd[i].name.len);
ngx_write_stdout(":" NGX_LINEFEED);
b = cd[i].buffer;
(void) ngx_write_fd(ngx_stdout, b->pos, b->last - b->pos);
ngx_write_stdout(NGX_LINEFEED);
}
}
return 0;
}
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (ngx_log_redirect_stderr(cycle) != NGX_OK) {
return 1;
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle);
} else {
ngx_master_process_cycle(cycle);
}
return 0;
}
void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
char *title;
u_char *p;
size_t size;
ngx_int_t i;
ngx_uint_t n;
sigset_t set;
struct itimerval itv;
ngx_uint_t live;
ngx_msec_t delay;
ngx_listening_t *ls;
ngx_core_conf_t *ccf;
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGALRM);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGINT);
sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigprocmask() failed");
}
sigemptyset(&set);
size = sizeof(master_process);
for (i = 0; i < ngx_argc; i++) {
size += ngx_strlen(ngx_argv[i]) + 1;
}
title = ngx_pnalloc(cycle->pool, size);
p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
for (i = 0; i < ngx_argc; i++) {
*p++ = ' ';
p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
}
ngx_setproctitle(title);
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_new_binary = 0;
delay = 0;
live = 1;
for ( ;; ) {
if (delay) {
if (ngx_sigalrm) {
delay *= 2;
ngx_sigalrm = 0;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"termination cycle: %d", delay);
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = 0;
itv.it_value.tv_sec = delay / 1000;
itv.it_value.tv_usec = (delay % 1000 ) * 1000;
if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setitimer() failed");
}
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");
sigsuspend(&set);
ngx_time_update(0, 0);
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "wake up");
if (ngx_reap) {
ngx_reap = 0;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");
live = ngx_reap_children(cycle);
}
if (!live && (ngx_terminate || ngx_quit)) {
ngx_master_process_exit(cycle);
}
if (ngx_terminate) {
if (delay == 0) {
delay = 50;
}
if (delay > 1000) {
ngx_signal_worker_processes(cycle, SIGKILL);
} else {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_TERMINATE_SIGNAL));
}
continue;
}
if (ngx_quit) {
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
ls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
if (ngx_close_socket(ls[n].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[n].addr_text);
}
}
cycle->listening.nelts = 0;
continue;
}
if (ngx_reconfigure) {
ngx_reconfigure = 0;
if (ngx_new_binary) {
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_noaccepting = 0;
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_JUST_RESPAWN);
ngx_start_cache_manager_processes(cycle, 1);
live = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
if (ngx_restart) {
ngx_restart = 0;
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
live = 1;
}
if (ngx_reopen) {
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, ccf->user);
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_REOPEN_SIGNAL));
}
if (ngx_change_binary) {
ngx_change_binary = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
}
if (ngx_noaccept) {
ngx_noaccept = 0;
ngx_noaccepting = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
}
}
// main()函数里调用，仅启动一个进程，没有fork
// master_process off;
void
ngx_single_process_cycle(ngx_cycle_t *cycle)
{
ngx_uint_t i;
if (ngx_set_environment(cycle, NULL) == NULL) {
/* fatal */
exit(2);
}
// 调用所有模块的init_process，即进程启动时hook
for (i = 0; ngx_modules[i]; i++) {
if (ngx_modules[i]->init_process) {
if (ngx_modules[i]->init_process(cycle) == NGX_ERROR) {
/* fatal */
exit(2);
}
}
}
// 无限循环，对外提供服务
// ngx_signal_handler处理unix信号
// 收到信号后设置ngx_quit/ngx_sigalrm/ngx_reconfigue等全局变量
// 由无限循环检查这些变量再处理
for ( ;; ) {
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "worker cycle");
// 处理事件的核心函数, event模块里
// 处理socket读写事件和定时器事件
// 获取负载均衡锁，监听端口接受连接
// 调用epoll模块的ngx_epoll_process_events
// 然后处理超时事件和在延后队列里的所有事件
// nginx大部分的工作量都在这里
ngx_process_events_and_timers(cycle);
// 检查是否处于退出状态
// 这里不使用ngx_exiting变量，直接关闭端口退出
if (ngx_terminate || ngx_quit) {
// 所有模块的退出hook
for (i = 0; ngx_modules[i]; i++) {
if (ngx_modules[i]->exit_process) {
ngx_modules[i]->exit_process(cycle);
}
}
// 删除pid，模块清理，关闭监听端口
// 内部直接exit(0)退出
ngx_master_process_exit(cycle);
}
// 重新配置，以当前cycle重新初始化，即reload
if (ngx_reconfigure) {
ngx_reconfigure = 0; //标志量清零
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
// 以当前cycle重新初始化
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
}
// 重新打开所有文件
if (ngx_reopen) {
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, (ngx_uid_t) -1);
}
} // 无限循环，对外提供服务
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_int_t i;
ngx_log_t *log;
ngx_cycle_t *cycle, init_cycle;
ngx_core_conf_t *ccf;
ngx_debug_init();
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_write_stderr("Tengine version: " TENGINE_VER " (" NGINX_VER ")"
NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvmVtdq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -m : show all modules and exit" NGX_LINEFEED
" -l : show all directives and exit" NGX_LINEFEED
" -V : show version, modules and configure options "
"then exit" NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED
" -d : dump configuration and exit" NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
ngx_write_stderr(
#ifdef NGX_COMPILER
"built by " NGX_COMPILER NGX_LINEFEED
#endif
#if (NGX_SSL)
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
"TLS SNI support enabled" NGX_LINEFEED
#else
"TLS SNI support disabled" NGX_LINEFEED
#endif
#endif
"configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
if(!ngx_test_config && !ngx_show_modules && !ngx_show_directives) {
return 0;
}
}
/* TODO */ ngx_max_sockets = -1;
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
return 0;
}
if (ngx_show_modules || ngx_show_directives) {
return 0;
}
if (ngx_dump_config) {
return 0;
}
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
if (ngx_open_pipes(cycle) == NGX_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, 0, "can not open pipes");
return 1;
}
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (cycle->log->file->fd != ngx_stderr) {
if (ngx_set_stderr(cycle->log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
ngx_set_stderr_n " failed");
return 1;
}
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle);
} else {
ngx_master_process_cycle(cycle);
}
return 0;
}
void
ngx_master_process_cycle(ngx_cycle_t *cycle)
{
char *title;
u_char *p;
size_t size;
ngx_int_t i;
ngx_uint_t n, sigio;
sigset_t set;
struct itimerval itv;
ngx_uint_t live;
ngx_msec_t delay;
ngx_listening_t *ls;
ngx_core_conf_t *ccf;
//屏蔽一系列信号，防止被打扰
sigemptyset(&set);
sigaddset(&set, SIGCHLD);
sigaddset(&set, SIGALRM);
sigaddset(&set, SIGIO);
sigaddset(&set, SIGINT);
sigaddset(&set, ngx_signal_value(NGX_RECONFIGURE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_REOPEN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_NOACCEPT_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_TERMINATE_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
sigaddset(&set, ngx_signal_value(NGX_CHANGEBIN_SIGNAL));
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"sigprocmask() failed");
}
sigemptyset(&set);
// master_process 静态数组。参考本页
size = sizeof(master_process);
for (i = 0; i < ngx_argc; i++) {
size += ngx_strlen(ngx_argv[i]) + 1;
}
title = ngx_pnalloc(cycle->pool, size);
p = ngx_cpymem(title, master_process, sizeof(master_process) - 1);
for (i = 0; i < ngx_argc; i++) {
*p++ = ' ';
p = ngx_cpystrn(p, (u_char *) ngx_argv[i], size);
}
ngx_setproctitle(title);
//master进程获取core模块配置，ccf中有要创建多少个worker的设定
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
//启动worker,这时已经有了worker进程
// NGX_PROCESS_RESPAWN 表示重新生成子进程
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0); //创建有关cache的子进程
ngx_new_binary = 0;
delay = 0;
sigio = 0;
live = 1;
for ( ;; ) {
//delay用来等待子进程退出的时间，由于我们接受到SIGINT信号后，我们需要先发送信号给子进程，
//而子进程的退出需要一定的时间，超时时如果子进程已退出，我们父进程就直接退出，
//否则发送sigkill信号给子进程(强制退出),然后再退出。
if (delay) {
if (ngx_sigalrm) {
sigio = 0;
delay *= 2;
ngx_sigalrm = 0;
}
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"termination cycle: %d", delay);
itv.it_interval.tv_sec = 0;
itv.it_interval.tv_usec = 0;
itv.it_value.tv_sec = delay / 1000;
itv.it_value.tv_usec = (delay % 1000 ) * 1000;
//设置定时器
if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
"setitimer() failed");
}
}
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "sigsuspend");
//延时，等待信号
sigsuspend(&set); //调用这个将master进程挂起来
ngx_time_update();
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"wake up, sigio %i", sigio);
//ngx_reap为1，说明有子进程已经退出
if (ngx_reap) {
ngx_reap = 0;
ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "reap children");
//这个里面处理退出的子进程(有的worker异常退出，这时我们就需要重启这个worker )，如果所有子进程都退出则会返回0.
live = ngx_reap_children(cycle);
}
//如果没有存活的子进程，并且收到了ngx_terminate或者ngx_quit信号，则master退出。
if (!live && (ngx_terminate || ngx_quit)) {
ngx_master_process_exit(cycle);
}
//收到了sigint信号
if (ngx_terminate) {
//设置延时
if (delay == 0) {
delay = 50;
}
if (sigio) {
sigio--;
continue;
}
sigio = ccf->worker_processes + 2 /* cache processes */;
if (delay > 1000) {
//如果超时，则强制杀死worker
ngx_signal_worker_processes(cycle, SIGKILL);
} else {
//负责发送sigint给worker，让它退出
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_TERMINATE_SIGNAL));
}
continue;
}
//收到quit信号
if (ngx_quit) {
//发送给worker quit信号
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
ls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
if (ngx_close_socket(ls[n].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[n].addr_text);
}
}
cycle->listening.nelts = 0;
continue;
}
//收到需要reconfig的信号
if (ngx_reconfigure) {
ngx_reconfigure = 0;
//判断是否热代码替换后的新的代码还在运行中(也就是还没退出当前的master)。如果还在运行中，则不需要重新初始化config
if (ngx_new_binary) {
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
ngx_noaccepting = 0;
continue;
}
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");
//重新初始化config，并重新启动新的worker
cycle = ngx_init_cycle(cycle);
if (cycle == NULL) {
cycle = (ngx_cycle_t *) ngx_cycle;
continue;
}
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_JUST_RESPAWN);
ngx_start_cache_manager_processes(cycle, 1);
live = 1;
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
if (ngx_restart) {
ngx_restart = 0;
ngx_start_worker_processes(cycle, ccf->worker_processes,
NGX_PROCESS_RESPAWN);
ngx_start_cache_manager_processes(cycle, 0);
live = 1;
}
//重新打开
if (ngx_reopen) {
ngx_reopen = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
ngx_reopen_files(cycle, ccf->user);
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_REOPEN_SIGNAL));
}
//热代码替换
if (ngx_change_binary) {
ngx_change_binary = 0;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "changing binary");
//进行热代码替换，这里是调用execve来执行新的代码
ngx_new_binary = ngx_exec_new_binary(cycle, ngx_argv);
}
//接受到停止accept连接，其实也就是worker退出(有区别的是，这里master不需要退出)
if (ngx_noaccept) {
ngx_noaccept = 0;
ngx_noaccepting = 1;
//给worker发送信号
ngx_signal_worker_processes(cycle,
ngx_signal_value(NGX_SHUTDOWN_SIGNAL));
}
}
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_int_t i;
ngx_log_t *log;
ngx_cycle_t *cycle, init_cycle;
ngx_core_conf_t *ccf;
#if (NGX_FREEBSD)
ngx_debug_init();
#endif
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
//获取参数和配置参数，比如命令是nginx -v 那么ngx_show_version就设置为1
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_write_stderr("nginx version: " NGINX_VER NGX_LINEFEED);
if (ngx_show_help) {
ngx_write_stderr(
"Usage: nginx [-?hvVtq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" NGX_LINEFEED
NGX_LINEFEED
"Options:" NGX_LINEFEED
" -?,-h : this help" NGX_LINEFEED
" -v : show version and exit" NGX_LINEFEED
" -V : show version and configure options then exit"
NGX_LINEFEED
" -t : test configuration and exit" NGX_LINEFEED
" -q : suppress non-error messages "
"during configuration testing" NGX_LINEFEED
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" NGX_LINEFEED
#else
" -p prefix : set prefix path (default: NONE)" NGX_LINEFEED
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" NGX_LINEFEED
" -g directives : set global directives out of configuration "
"file" NGX_LINEFEED NGX_LINEFEED
);
}
if (ngx_show_configure) {
ngx_write_stderr(
#ifdef NGX_COMPILER
"built by " NGX_COMPILER NGX_LINEFEED
#endif
#if (NGX_SSL)
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
"TLS SNI support enabled" NGX_LINEFEED
#else
"TLS SNI support disabled" NGX_LINEFEED
#endif
#endif
"configure arguments:" NGX_CONFIGURE NGX_LINEFEED);
}
if (!ngx_test_config) {
return 0;
}
}
/* TODO */
ngx_max_sockets = -1;
//初始化nginx环境的当前时间
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
//master pid， 获取当前进程ID
ngx_pid = ngx_getpid();
// 初始化日志，如打开日志文件
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log); //是否开启了ssl，如果开启在这里进行初始化
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
// 为cycle创建一个1024B的内存池
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
// 保存参数到全局变量中
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
// 初始化init_cycle中的一些如: conf_file，prefix，conf_prefix等字段
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
// 初始化系统相关变量，如内存页面大小ngx_pagesize,ngx_cacheline_size,最大连接数ngx_max_sockets等
if (ngx_os_init(log) != NGX_OK) { // 这个ngx_os_init在不同操作系统调用不同的函数
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/
// 初始化CRC表，提高效率，以后就不用计算了，直接用
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
// 继承sockets,继承来的socket将会放到init_cycle的listening数组
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
// 计算模块个数，并且设置各个模块顺序（索引）
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) { // 这里面的ngx_modules会有非常多的模块，[ngx_core_module,ngx_errlog_module,ngx_conf_moduel]
ngx_modules[i]->index = ngx_max_module++;
}
// 对ngx_cycle结构进行初始化,这里是nginx启动核心之处！
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
return 0;
}
// 检查是否有设置信号处理，如有，进入ngx_signal_process处理
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) { //如果是daemon模式，本进程变为守护进程
return 1;
}
ngx_daemonized = 1;
}
if (ngx_inherited) {
ngx_daemonized = 1;
}
#endif
// 创建进程记录文件
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
if (cycle->log->file->fd != ngx_stderr) {
if (ngx_set_stderr(cycle->log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
ngx_set_stderr_n " failed");
return 1;
}
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle); //单进程
} else {
ngx_master_process_cycle(cycle); //多进程，master进程进入这个，这个函数在不同操作系统有不同实现。
}
return 0;
}
int ngx_cdecl
main(int argc, char *const *argv)
{
ngx_int_t i;
ngx_log_t *log;
ngx_cycle_t *cycle, init_cycle;
ngx_core_conf_t *ccf;
if (ngx_strerror_init() != NGX_OK) {
return 1;
}
//get options input on start up
if (ngx_get_options(argc, argv) != NGX_OK) {
return 1;
}
if (ngx_show_version) {
ngx_log_stderr(0, "nginx version: " NGINX_VER);
if (ngx_show_help) {
ngx_log_stderr(0,
"Usage: nginx [-?hvVtq] [-s signal] [-c filename] "
"[-p prefix] [-g directives]" CRLF CRLF
"Options:" CRLF
" -?,-h : this help" CRLF
" -v : show version and exit" CRLF
" -V : show version and configure options then exit"
CRLF
" -t : test configuration and exit" CRLF
" -q : suppress non-error messages "
"during configuration testing" CRLF
" -s signal : send signal to a master process: "
"stop, quit, reopen, reload" CRLF
#ifdef NGX_PREFIX
" -p prefix : set prefix path (default: "
NGX_PREFIX ")" CRLF
#else
" -p prefix : set prefix path (default: NONE)" CRLF
#endif
" -c filename : set configuration file (default: "
NGX_CONF_PATH ")" CRLF
" -g directives : set global directives out of configuration "
"file" CRLF
);
}
if (ngx_show_configure) {
#ifdef NGX_COMPILER
ngx_log_stderr(0, "built by " NGX_COMPILER);
#endif
#if (NGX_SSL)
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
ngx_log_stderr(0, "TLS SNI support enabled");
#else
ngx_log_stderr(0, "TLS SNI support disabled");
#endif
#endif
ngx_log_stderr(0, "configure arguments:" NGX_CONFIGURE);
}
if (!ngx_test_config) {
return 0;
}
}
#if (NGX_FREEBSD)
ngx_debug_init();
#endif
/* TODO */ ngx_max_sockets = -1;
//调用ngx_time_init()初始化并更新时间
ngx_time_init();
#if (NGX_PCRE)
ngx_regex_init();
#endif
ngx_pid = ngx_getpid();
//init log,调用ngx_log_init()初始化日志，如初始化全局变量ngx_prefix，打开日志文件ngx_log_file.fd
log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return 1;
}
/* STUB */
#if (NGX_OPENSSL)
ngx_ssl_init(log);
#endif
/*
* init_cycle->log is required for signal handlers and
* ngx_process_options()
*/
//清零
ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
init_cycle.log = log;
ngx_cycle = &init_cycle;
//创建内存池
init_cycle.pool = ngx_create_pool(1024, log);
if (init_cycle.pool == NULL) {
return 1;
}
//命令行参数保存到ngx_os_argv、ngx_argc以及ngx_argv这几个全局的变量中。这算是一个备份存储，方便以后master进程做热代码替换之用
if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return 1;
}
//初始化ngx_cycle的prefix, conf_prefix, conf_file, conf_param等字段
if (ngx_process_options(&init_cycle) != NGX_OK) {
return 1;
}
//调用ngx_os_init()初始化系统相关变量，如内存页面大小ngx_pagesize,ngx_cacheline_size,最大连接数ngx_max_sockets等；
if (ngx_os_init(log) != NGX_OK) {
return 1;
}
/*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
调用ngx_crc32_table_init()初始化CRC表(后续的CRC校验通过查表进行，效率高)
*/
if (ngx_crc32_table_init() != NGX_OK) {
return 1;
}
/*
" 调用ngx_add_inherited_sockets()继承sockets；
o 解析环境变量NGINX_VAR="NGINX"中的sockets，并保存至ngx_cycle.listening数组；
o 设置ngx_inherited=1；
o 调用ngx_set_inherited_sockets()逐一对ngx_cycle.listening数组中的sockets进行设置
*/
if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return 1;
}
//初始化全局模块数组当中每个模块的index
//这个神秘的数组却是在自动编译的时候生成的，位于objs/ngx_modules.c文件中。这个循环的目的是清晰可见的--对所有模块进行索引编号，方便以后访问
ngx_max_module = 0;
for (i = 0; ngx_modules[i]; i++) {
ngx_modules[i]->index = ngx_max_module++;
}
//o 该初始化主要对ngx_cycle结构进行,核心!!
cycle = ngx_init_cycle(&init_cycle);
if (cycle == NULL) {
if (ngx_test_config) {
ngx_log_stderr(0, "configuration file %s test failed",
init_cycle.conf_file.data);
}
return 1;
}
if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(0, "configuration file %s test is successful",
cycle->conf_file.data);
}
return 0;
}
//" 若有信号，则进入ngx_signal_process()处理
if (ngx_signal) {
return ngx_signal_process(cycle, ngx_signal);
}
ngx_os_status(cycle->log);
ngx_cycle = cycle;
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ccf->master && ngx_process == NGX_PROCESS_SINGLE) {
ngx_process = NGX_PROCESS_MASTER;
}
#if !(NGX_WIN32)
//主要完成信号处理程序的注册
if (ngx_init_signals(cycle->log) != NGX_OK) {
return 1;
}
//" 若无继承sockets，且设置了守护进程标识，则调用ngx_daemon()创建守护进程
if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return 1;
}
ngx_daemonized = 1;
}
#endif
//" 调用ngx_create_pidfile()创建进程记录文件
if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return 1;
}
//log file is OK
if (cycle->log->file->fd != ngx_stderr) {
if (ngx_set_stderr(cycle->log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
ngx_set_stderr_n " failed");
return 1;
}
}
if (log->file->fd != ngx_stderr) {
if (ngx_close_file(log->file->fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_close_file_n " built-in log failed");
}
}
ngx_use_stderr = 0;
//进入进程主循环
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle); //单进程模式
} else {
ngx_master_process_cycle(cycle); //master-slave模式这个过程里实现了master-worker模式的进程模型，也是生成环境下Nginx的常用模型
}
return 0;
}
