Nginx的启动过程
主要介绍Nginx的启动过程，可以在/core/nginx.c中找到Nginx的主函数main()，那么就从这里开始分析Nginx的启动过程。
涉及到的基本函数
源码：
/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/ #include <ngx_config.h>
#include <ngx_core.h>
#include <nginx.h> static ngx_int_t ngx_add_inherited_sockets(ngx_cycle_t *cycle);
static ngx_int_t ngx_get_options(int argc, char *const *argv);
static ngx_int_t ngx_process_options(ngx_cycle_t *cycle);
static ngx_int_t ngx_save_argv(ngx_cycle_t *cycle, int argc, char *const *argv);
static void *ngx_core_module_create_conf(ngx_cycle_t *cycle);
static char *ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf);
static char *ngx_set_user(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_env(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_priority(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static char *ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf); static ngx_conf_enum_t ngx_debug_points[] = {
{ ngx_string("stop"), NGX_DEBUG_POINTS_STOP },
{ ngx_string("abort"), NGX_DEBUG_POINTS_ABORT },
{ ngx_null_string, }
}; static ngx_command_t ngx_core_commands[] = { { ngx_string("daemon"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG,
ngx_conf_set_flag_slot,
,
offsetof(ngx_core_conf_t, daemon),
NULL }, { ngx_string("master_process"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG,
ngx_conf_set_flag_slot,
,
offsetof(ngx_core_conf_t, master),
NULL }, { ngx_string("timer_resolution"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_msec_slot,
,
offsetof(ngx_core_conf_t, timer_resolution),
NULL }, { ngx_string("pid"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_str_slot,
,
offsetof(ngx_core_conf_t, pid),
NULL }, { ngx_string("lock_file"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_str_slot,
,
offsetof(ngx_core_conf_t, lock_file),
NULL }, { ngx_string("worker_processes"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_set_worker_processes,
,
,
NULL }, { ngx_string("debug_points"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_enum_slot,
,
offsetof(ngx_core_conf_t, debug_points),
&ngx_debug_points }, { ngx_string("user"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE12,
ngx_set_user,
,
,
NULL }, { ngx_string("worker_priority"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_set_priority,
,
,
NULL }, { ngx_string("worker_cpu_affinity"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_1MORE,
ngx_set_cpu_affinity,
,
,
NULL }, { ngx_string("worker_rlimit_nofile"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
,
offsetof(ngx_core_conf_t, rlimit_nofile),
NULL }, { ngx_string("worker_rlimit_core"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_off_slot,
,
offsetof(ngx_core_conf_t, rlimit_core),
NULL }, { ngx_string("worker_rlimit_sigpending"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
,
offsetof(ngx_core_conf_t, rlimit_sigpending),
NULL }, { ngx_string("working_directory"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_str_slot,
,
offsetof(ngx_core_conf_t, working_directory),
NULL }, { ngx_string("env"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_set_env,
,
,
NULL }, #if (NGX_THREADS) { ngx_string("worker_threads"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
,
offsetof(ngx_core_conf_t, worker_threads),
NULL }, { ngx_string("thread_stack_size"),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_conf_set_size_slot,
,
offsetof(ngx_core_conf_t, thread_stack_size),
NULL }, #endif ngx_null_command
}; static ngx_core_module_t ngx_core_module_ctx = {
ngx_string("core"),
ngx_core_module_create_conf,
ngx_core_module_init_conf
}; ngx_module_t ngx_core_module = {
NGX_MODULE_V1,
&ngx_core_module_ctx, /* module context */
ngx_core_commands, /* module directives */
NGX_CORE_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
NULL, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
NULL, /* exit process */
NULL, /* exit master */
NGX_MODULE_V1_PADDING
}; ngx_uint_t ngx_max_module; static ngx_uint_t ngx_show_help;
static ngx_uint_t ngx_show_version;
static ngx_uint_t ngx_show_configure;
static u_char *ngx_prefix;
static u_char *ngx_conf_file;
static u_char *ngx_conf_params;
static char *ngx_signal; static char **ngx_os_environ; 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 ;
} if (ngx_get_options(argc, argv) != NGX_OK) {
return ;
} 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 ;
}
} /* TODO */ ngx_max_sockets = -; ngx_time_init(); #if (NGX_PCRE)
ngx_regex_init();
#endif ngx_pid = ngx_getpid(); log = ngx_log_init(ngx_prefix);
if (log == NULL) {
return ;
} /* 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(, log);
if (init_cycle.pool == NULL) {
return ;
} if (ngx_save_argv(&init_cycle, argc, argv) != NGX_OK) {
return ;
} if (ngx_process_options(&init_cycle) != NGX_OK) {
return ;
} if (ngx_os_init(log) != NGX_OK) {
return ;
} /*
* ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
*/ if (ngx_crc32_table_init() != NGX_OK) {
return ;
} if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
return ;
} ngx_max_module = ;
for (i = ; 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(, "configuration file %s test failed",
init_cycle.conf_file.data);
} return ;
} if (ngx_test_config) {
if (!ngx_quiet_mode) {
ngx_log_stderr(, "configuration file %s test is successful",
cycle->conf_file.data);
} return ;
} 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 ;
} if (!ngx_inherited && ccf->daemon) {
if (ngx_daemon(cycle->log) != NGX_OK) {
return ;
} ngx_daemonized = ;
} if (ngx_inherited) {
ngx_daemonized = ;
} #endif if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) {
return ;
} 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 ;
}
} 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 = ; if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle); } else {
ngx_master_process_cycle(cycle);
} return ;
} static ngx_int_t
ngx_add_inherited_sockets(ngx_cycle_t *cycle)
{
u_char *p, *v, *inherited;
ngx_int_t s;
ngx_listening_t *ls; inherited = (u_char *) getenv(NGINX_VAR); if (inherited == NULL) {
return NGX_OK;
} ngx_log_error(NGX_LOG_NOTICE, cycle->log, ,
"using inherited sockets from \"%s\"", inherited); if (ngx_array_init(&cycle->listening, cycle->pool, ,
sizeof(ngx_listening_t))
!= NGX_OK)
{
return NGX_ERROR;
} for (p = inherited, v = p; *p; p++) {
if (*p == ':' || *p == ';') {
s = ngx_atoi(v, p - v);
if (s == NGX_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ,
"invalid socket number \"%s\" in " NGINX_VAR
" environment variable, ignoring the rest"
" of the variable", v);
break;
} v = p + ; ls = ngx_array_push(&cycle->listening);
if (ls == NULL) {
return NGX_ERROR;
} ngx_memzero(ls, sizeof(ngx_listening_t)); ls->fd = (ngx_socket_t) s;
}
} ngx_inherited = ; return ngx_set_inherited_sockets(cycle);
} char **
ngx_set_environment(ngx_cycle_t *cycle, ngx_uint_t *last)
{
char **p, **env;
ngx_str_t *var;
ngx_uint_t i, n;
ngx_core_conf_t *ccf; ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module); if (last == NULL && ccf->environment) {
return ccf->environment;
} var = ccf->env.elts; for (i = ; i < ccf->env.nelts; i++) {
if (ngx_strcmp(var[i].data, "TZ") ==
|| ngx_strncmp(var[i].data, "TZ=", ) == )
{
goto tz_found;
}
} var = ngx_array_push(&ccf->env);
if (var == NULL) {
return NULL;
} var->len = ;
var->data = (u_char *) "TZ"; var = ccf->env.elts; tz_found: n = ; for (i = ; i < ccf->env.nelts; i++) { if (var[i].data[var[i].len] == '=') {
n++;
continue;
} for (p = ngx_os_environ; *p; p++) { if (ngx_strncmp(*p, var[i].data, var[i].len) ==
&& (*p)[var[i].len] == '=')
{
n++;
break;
}
}
} if (last) {
env = ngx_alloc((*last + n + ) * sizeof(char *), cycle->log);
*last = n; } else {
env = ngx_palloc(cycle->pool, (n + ) * sizeof(char *));
} if (env == NULL) {
return NULL;
} n = ; for (i = ; i < ccf->env.nelts; i++) { if (var[i].data[var[i].len] == '=') {
env[n++] = (char *) var[i].data;
continue;
} for (p = ngx_os_environ; *p; p++) { if (ngx_strncmp(*p, var[i].data, var[i].len) ==
&& (*p)[var[i].len] == '=')
{
env[n++] = *p;
break;
}
}
} env[n] = NULL; if (last == NULL) {
ccf->environment = env;
environ = env;
} return env;
} ngx_pid_t
ngx_exec_new_binary(ngx_cycle_t *cycle, char *const *argv)
{
char **env, *var;
u_char *p;
ngx_uint_t i, n;
ngx_pid_t pid;
ngx_exec_ctx_t ctx;
ngx_core_conf_t *ccf;
ngx_listening_t *ls; ngx_memzero(&ctx, sizeof(ngx_exec_ctx_t)); ctx.path = argv[];
ctx.name = "new binary process";
ctx.argv = argv; n = ;
env = ngx_set_environment(cycle, &n);
if (env == NULL) {
return NGX_INVALID_PID;
} var = ngx_alloc(sizeof(NGINX_VAR)
+ cycle->listening.nelts * (NGX_INT32_LEN + ) + ,
cycle->log);
if (var == NULL) {
ngx_free(env);
return NGX_INVALID_PID;
} p = ngx_cpymem(var, NGINX_VAR "=", sizeof(NGINX_VAR)); ls = cycle->listening.elts;
for (i = ; i < cycle->listening.nelts; i++) {
p = ngx_sprintf(p, "%ud;", ls[i].fd);
} *p = '\0'; env[n++] = var; #if (NGX_SETPROCTITLE_USES_ENV) /* allocate the spare 300 bytes for the new binary process title */ env[n++] = "SPARE=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"; #endif env[n] = NULL; #if (NGX_DEBUG)
{
char **e;
for (e = env; *e; e++) {
ngx_log_debug1(NGX_LOG_DEBUG_CORE, cycle->log, , "env: %s", *e);
}
}
#endif ctx.envp = (char *const *) env; ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module); if (ngx_rename_file(ccf->pid.data, ccf->oldpid.data) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_rename_file_n " %s to %s failed "
"before executing new binary process \"%s\"",
ccf->pid.data, ccf->oldpid.data, argv[]); ngx_free(env);
ngx_free(var); return NGX_INVALID_PID;
} pid = ngx_execute(cycle, &ctx); if (pid == NGX_INVALID_PID) {
if (ngx_rename_file(ccf->oldpid.data, ccf->pid.data)
== NGX_FILE_ERROR)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_rename_file_n " %s back to %s failed after "
"an attempt to execute new binary process \"%s\"",
ccf->oldpid.data, ccf->pid.data, argv[]);
}
} ngx_free(env);
ngx_free(var); return pid;
} static ngx_int_t
ngx_get_options(int argc, char *const *argv)
{
u_char *p;
ngx_int_t i; for (i = ; i < argc; i++) { p = (u_char *) argv[i]; if (*p++ != '-') {
ngx_log_stderr(, "invalid option: \"%s\"", argv[i]);
return NGX_ERROR;
} while (*p) { switch (*p++) { case '?':
case 'h':
ngx_show_version = ;
ngx_show_help = ;
break; case 'v':
ngx_show_version = ;
break; case 'V':
ngx_show_version = ;
ngx_show_configure = ;
break; case 't':
ngx_test_config = ;
break; case 'q':
ngx_quiet_mode = ;
break; case 'p':
if (*p) {
ngx_prefix = p;
goto next;
} if (argv[++i]) {
ngx_prefix = (u_char *) argv[i];
goto next;
} ngx_log_stderr(, "option \"-p\" requires directory name");
return NGX_ERROR; case 'c':
if (*p) {
ngx_conf_file = p;
goto next;
} if (argv[++i]) {
ngx_conf_file = (u_char *) argv[i];
goto next;
} ngx_log_stderr(, "option \"-c\" requires file name");
return NGX_ERROR; case 'g':
if (*p) {
ngx_conf_params = p;
goto next;
} if (argv[++i]) {
ngx_conf_params = (u_char *) argv[i];
goto next;
} ngx_log_stderr(, "option \"-g\" requires parameter");
return NGX_ERROR; case 's':
if (*p) {
ngx_signal = (char *) p; } else if (argv[++i]) {
ngx_signal = argv[i]; } else {
ngx_log_stderr(, "option \"-s\" requires parameter");
return NGX_ERROR;
} if (ngx_strcmp(ngx_signal, "stop") ==
|| ngx_strcmp(ngx_signal, "quit") ==
|| ngx_strcmp(ngx_signal, "reopen") ==
|| ngx_strcmp(ngx_signal, "reload") == )
{
ngx_process = NGX_PROCESS_SIGNALLER;
goto next;
} ngx_log_stderr(, "invalid option: \"-s %s\"", ngx_signal);
return NGX_ERROR; default:
ngx_log_stderr(, "invalid option: \"%c\"", *(p - ));
return NGX_ERROR;
}
} next: continue;
} return NGX_OK;
} static ngx_int_t
ngx_save_argv(ngx_cycle_t *cycle, int argc, char *const *argv)
{
#if (NGX_FREEBSD) ngx_os_argv = (char **) argv;
ngx_argc = argc;
ngx_argv = (char **) argv; #else
size_t len;
ngx_int_t i; ngx_os_argv = (char **) argv;
ngx_argc = argc; ngx_argv = ngx_alloc((argc + ) * sizeof(char *), cycle->log);
if (ngx_argv == NULL) {
return NGX_ERROR;
} for (i = ; i < argc; i++) {
len = ngx_strlen(argv[i]) + ; ngx_argv[i] = ngx_alloc(len, cycle->log);
if (ngx_argv[i] == NULL) {
return NGX_ERROR;
} (void) ngx_cpystrn((u_char *) ngx_argv[i], (u_char *) argv[i], len);
} ngx_argv[i] = NULL; #endif ngx_os_environ = environ; return NGX_OK;
} static ngx_int_t
ngx_process_options(ngx_cycle_t *cycle)
{
u_char *p;
size_t len; if (ngx_prefix) {
len = ngx_strlen(ngx_prefix);
p = ngx_prefix; if (len && !ngx_path_separator(p[len - ])) {
p = ngx_pnalloc(cycle->pool, len + );
if (p == NULL) {
return NGX_ERROR;
} ngx_memcpy(p, ngx_prefix, len);
p[len++] = '/';
} cycle->conf_prefix.len = len;
cycle->conf_prefix.data = p;
cycle->prefix.len = len;
cycle->prefix.data = p; } else { #ifndef NGX_PREFIX p = ngx_pnalloc(cycle->pool, NGX_MAX_PATH);
if (p == NULL) {
return NGX_ERROR;
} if (ngx_getcwd(p, NGX_MAX_PATH) == ) {
ngx_log_stderr(ngx_errno, "[emerg]: " ngx_getcwd_n " failed");
return NGX_ERROR;
} len = ngx_strlen(p); p[len++] = '/'; cycle->conf_prefix.len = len;
cycle->conf_prefix.data = p;
cycle->prefix.len = len;
cycle->prefix.data = p; #else #ifdef NGX_CONF_PREFIX
ngx_str_set(&cycle->conf_prefix, NGX_CONF_PREFIX);
#else
ngx_str_set(&cycle->conf_prefix, NGX_PREFIX);
#endif
ngx_str_set(&cycle->prefix, NGX_PREFIX); #endif
} if (ngx_conf_file) {
cycle->conf_file.len = ngx_strlen(ngx_conf_file);
cycle->conf_file.data = ngx_conf_file; } else {
ngx_str_set(&cycle->conf_file, NGX_CONF_PATH);
} if (ngx_conf_full_name(cycle, &cycle->conf_file, ) != NGX_OK) {
return NGX_ERROR;
} for (p = cycle->conf_file.data + cycle->conf_file.len - ;
p > cycle->conf_file.data;
p--)
{
if (ngx_path_separator(*p)) {
cycle->conf_prefix.len = p - ngx_cycle->conf_file.data + ;
cycle->conf_prefix.data = ngx_cycle->conf_file.data;
break;
}
} if (ngx_conf_params) {
cycle->conf_param.len = ngx_strlen(ngx_conf_params);
cycle->conf_param.data = ngx_conf_params;
} if (ngx_test_config) {
cycle->log->log_level = NGX_LOG_INFO;
} return NGX_OK;
} static void *
ngx_core_module_create_conf(ngx_cycle_t *cycle)
{
ngx_core_conf_t *ccf; ccf = ngx_pcalloc(cycle->pool, sizeof(ngx_core_conf_t));
if (ccf == NULL) {
return NULL;
} /*
* set by ngx_pcalloc()
*
* ccf->pid = NULL;
* ccf->oldpid = NULL;
* ccf->priority = 0;
* ccf->cpu_affinity_n = 0;
* ccf->cpu_affinity = NULL;
*/ ccf->daemon = NGX_CONF_UNSET;
ccf->master = NGX_CONF_UNSET;
ccf->timer_resolution = NGX_CONF_UNSET_MSEC; ccf->worker_processes = NGX_CONF_UNSET;
ccf->debug_points = NGX_CONF_UNSET; ccf->rlimit_nofile = NGX_CONF_UNSET;
ccf->rlimit_core = NGX_CONF_UNSET;
ccf->rlimit_sigpending = NGX_CONF_UNSET; ccf->user = (ngx_uid_t) NGX_CONF_UNSET_UINT;
ccf->group = (ngx_gid_t) NGX_CONF_UNSET_UINT; #if (NGX_THREADS)
ccf->worker_threads = NGX_CONF_UNSET;
ccf->thread_stack_size = NGX_CONF_UNSET_SIZE;
#endif if (ngx_array_init(&ccf->env, cycle->pool, , sizeof(ngx_str_t))
!= NGX_OK)
{
return NULL;
} return ccf;
} static char *
ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
{
ngx_core_conf_t *ccf = conf; ngx_conf_init_value(ccf->daemon, );
ngx_conf_init_value(ccf->master, );
ngx_conf_init_msec_value(ccf->timer_resolution, ); ngx_conf_init_value(ccf->worker_processes, );
ngx_conf_init_value(ccf->debug_points, ); #if (NGX_HAVE_CPU_AFFINITY) if (ccf->cpu_affinity_n
&& ccf->cpu_affinity_n !=
&& ccf->cpu_affinity_n != (ngx_uint_t) ccf->worker_processes)
{
ngx_log_error(NGX_LOG_WARN, cycle->log, ,
"the number of \"worker_processes\" is not equal to "
"the number of \"worker_cpu_affinity\" masks, "
"using last mask for remaining worker processes");
} #endif #if (NGX_THREADS) ngx_conf_init_value(ccf->worker_threads, );
ngx_threads_n = ccf->worker_threads;
ngx_conf_init_size_value(ccf->thread_stack_size, * * ); #endif if (ccf->pid.len == ) {
ngx_str_set(&ccf->pid, NGX_PID_PATH);
} if (ngx_conf_full_name(cycle, &ccf->pid, ) != NGX_OK) {
return NGX_CONF_ERROR;
} ccf->oldpid.len = ccf->pid.len + sizeof(NGX_OLDPID_EXT); ccf->oldpid.data = ngx_pnalloc(cycle->pool, ccf->oldpid.len);
if (ccf->oldpid.data == NULL) {
return NGX_CONF_ERROR;
} ngx_memcpy(ngx_cpymem(ccf->oldpid.data, ccf->pid.data, ccf->pid.len),
NGX_OLDPID_EXT, sizeof(NGX_OLDPID_EXT)); #if !(NGX_WIN32) if (ccf->user == (uid_t) NGX_CONF_UNSET_UINT && geteuid() == ) {
struct group *grp;
struct passwd *pwd; ngx_set_errno();
pwd = getpwnam(NGX_USER);
if (pwd == NULL) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"getpwnam(\"" NGX_USER "\") failed");
return NGX_CONF_ERROR;
} ccf->username = NGX_USER;
ccf->user = pwd->pw_uid; ngx_set_errno();
grp = getgrnam(NGX_GROUP);
if (grp == NULL) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
"getgrnam(\"" NGX_GROUP "\") failed");
return NGX_CONF_ERROR;
} ccf->group = grp->gr_gid;
} if (ccf->lock_file.len == ) {
ngx_str_set(&ccf->lock_file, NGX_LOCK_PATH);
} if (ngx_conf_full_name(cycle, &ccf->lock_file, ) != NGX_OK) {
return NGX_CONF_ERROR;
} {
ngx_str_t lock_file; lock_file = cycle->old_cycle->lock_file; if (lock_file.len) {
lock_file.len--; if (ccf->lock_file.len != lock_file.len
|| ngx_strncmp(ccf->lock_file.data, lock_file.data, lock_file.len)
!= )
{
ngx_log_error(NGX_LOG_EMERG, cycle->log, ,
"\"lock_file\" could not be changed, ignored");
} cycle->lock_file.len = lock_file.len + ;
lock_file.len += sizeof(".accept"); cycle->lock_file.data = ngx_pstrdup(cycle->pool, &lock_file);
if (cycle->lock_file.data == NULL) {
return NGX_CONF_ERROR;
} } else {
cycle->lock_file.len = ccf->lock_file.len + ;
cycle->lock_file.data = ngx_pnalloc(cycle->pool,
ccf->lock_file.len + sizeof(".accept"));
if (cycle->lock_file.data == NULL) {
return NGX_CONF_ERROR;
} ngx_memcpy(ngx_cpymem(cycle->lock_file.data, ccf->lock_file.data,
ccf->lock_file.len),
".accept", sizeof(".accept"));
}
} #endif return NGX_CONF_OK;
} static char *
ngx_set_user(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
#if (NGX_WIN32) ngx_conf_log_error(NGX_LOG_WARN, cf, ,
"\"user\" is not supported, ignored"); return NGX_CONF_OK; #else ngx_core_conf_t *ccf = conf; char *group;
struct passwd *pwd;
struct group *grp;
ngx_str_t *value; if (ccf->user != (uid_t) NGX_CONF_UNSET_UINT) {
return "is duplicate";
} if (geteuid() != ) {
ngx_conf_log_error(NGX_LOG_WARN, cf, ,
"the \"user\" directive makes sense only "
"if the master process runs "
"with super-user privileges, ignored");
return NGX_CONF_OK;
} value = (ngx_str_t *) cf->args->elts; ccf->username = (char *) value[].data; ngx_set_errno();
pwd = getpwnam((const char *) value[].data);
if (pwd == NULL) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
"getpwnam(\"%s\") failed", value[].data);
return NGX_CONF_ERROR;
} ccf->user = pwd->pw_uid; group = (char *) ((cf->args->nelts == ) ? value[].data : value[].data); ngx_set_errno();
grp = getgrnam(group);
if (grp == NULL) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
"getgrnam(\"%s\") failed", group);
return NGX_CONF_ERROR;
} ccf->group = grp->gr_gid; return NGX_CONF_OK; #endif
} static char *
ngx_set_env(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_core_conf_t *ccf = conf; ngx_str_t *value, *var;
ngx_uint_t i; var = ngx_array_push(&ccf->env);
if (var == NULL) {
return NGX_CONF_ERROR;
} value = cf->args->elts;
*var = value[]; for (i = ; i < value[].len; i++) { if (value[].data[i] == '=') { var->len = i; return NGX_CONF_OK;
}
} return NGX_CONF_OK;
} static char *
ngx_set_priority(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_core_conf_t *ccf = conf; ngx_str_t *value;
ngx_uint_t n, minus; if (ccf->priority != ) {
return "is duplicate";
} value = cf->args->elts; if (value[].data[] == '-') {
n = ;
minus = ; } else if (value[].data[] == '+') {
n = ;
minus = ; } else {
n = ;
minus = ;
} ccf->priority = ngx_atoi(&value[].data[n], value[].len - n);
if (ccf->priority == NGX_ERROR) {
return "invalid number";
} if (minus) {
ccf->priority = -ccf->priority;
} return NGX_CONF_OK;
} static char *
ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
#if (NGX_HAVE_CPU_AFFINITY)
ngx_core_conf_t *ccf = conf; u_char ch;
uint64_t *mask;
ngx_str_t *value;
ngx_uint_t i, n; if (ccf->cpu_affinity) {
return "is duplicate";
} mask = ngx_palloc(cf->pool, (cf->args->nelts - ) * sizeof(uint64_t));
if (mask == NULL) {
return NGX_CONF_ERROR;
} ccf->cpu_affinity_n = cf->args->nelts - ;
ccf->cpu_affinity = mask; value = cf->args->elts; for (n = ; n < cf->args->nelts; n++) { if (value[n].len > ) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, ,
"\"worker_cpu_affinity\" supports up to 64 CPUs only");
return NGX_CONF_ERROR;
} mask[n - ] = ; for (i = ; i < value[n].len; i++) { ch = value[n].data[i]; if (ch == ' ') {
continue;
} mask[n - ] <<= ; if (ch == '') {
continue;
} if (ch == '') {
mask[n - ] |= ;
continue;
} ngx_conf_log_error(NGX_LOG_EMERG, cf, ,
"invalid character \"%c\" in \"worker_cpu_affinity\"",
ch);
return NGX_CONF_ERROR;
}
} #else ngx_conf_log_error(NGX_LOG_WARN, cf, ,
"\"worker_cpu_affinity\" is not supported "
"on this platform, ignored");
#endif return NGX_CONF_OK;
} uint64_t
ngx_get_cpu_affinity(ngx_uint_t n)
{
ngx_core_conf_t *ccf; ccf = (ngx_core_conf_t *) ngx_get_conf(ngx_cycle->conf_ctx,
ngx_core_module); if (ccf->cpu_affinity == NULL) {
return ;
} if (ccf->cpu_affinity_n > n) {
return ccf->cpu_affinity[n];
} return ccf->cpu_affinity[ccf->cpu_affinity_n - ];
} static char *
ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_str_t *value;
ngx_core_conf_t *ccf; ccf = (ngx_core_conf_t *) conf; if (ccf->worker_processes != NGX_CONF_UNSET) {
return "is duplicate";
} value = (ngx_str_t *) cf->args->elts; if (ngx_strcmp(value[].data, "auto") == ) {
ccf->worker_processes = ngx_ncpu;
return NGX_CONF_OK;
} ccf->worker_processes = ngx_atoi(value[].data, value[].len); if (ccf->worker_processes == NGX_ERROR) {
return "invalid value";
} return NGX_CONF_OK;
}
Nginx的启动包括了很多的初始化和处理函数。这些函数相对来说，有一部分非常复杂，暂且从简单开始，从整体上对Ngixnd的启动有一个了解，方便日后的分析与学习。
主要函数：
//完成socket的继承
static ngx_int_t ngx_add_inherited_sockets(ngx_cycle_t *cycle);
//对参数选项进行处理
static ngx_int_t ngx_get_options(int argc, char *const *argv);
//初始化ngx_cycle内的部分内容
static ngx_int_t ngx_process_options(ngx_cycle_t *cycle);
//命令行参数保存到ngx_os_argv、ngx_argc以及ngx_argv全局的变量中
static ngx_int_t ngx_save_argv(ngx_cycle_t *cycle, int argc, char *const *argv);
//创建模块的配置信息
static void *ngx_core_module_create_conf(ngx_cycle_t *cycle);
//初始化配置信息
static char *ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf);
static char *ngx_set_user(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_set_env(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
//设置优先级
static char *ngx_set_priority(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
//设置CPU亲和性
static char *ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
//设置worker进程
static char *ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
Nginx启动的主要流程
下图为Nginx的启动时函数的调用过程，其中大部分都是为了Nginx启动的初始化部分。从错误处理、参数设置、时间设置等方面进行初始化，并注册了我们需要的模块，最后根据信号选择单任务模式还是master-worker模式。
流程图：
初始化
主函数在开始对系统错误、参数、时间、系统变量、日志等进行了初始化。
//初始化系统中错误编号对应的含义
ngx_strerror_init();
//对参数选项进行处理
ngx_get_options(argc, argv);
//时间初始化
ngx_time_init();
//重置pcre内存管理的接口
ngx_regex_init();
//日志初始化
ngx_log_init(ngx_prefix);
//创建内存池
ngx_create_pool(1024, log);
//保存变量
ngx_save_argv();
//初始化ngx_cycle的prefix, conf_prefix, conf_file, conf_param
ngx_process_options();
//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
ngx_os_init();
//初始化CRC表(后续的CRC校验通过查表进行，效率高)
ngx_crc32_table_init();
主要工作
初始化完成后，需要先调用ngx_add_inherited_sockets函数继承socket，并储存在Listening数组中，在运行时候进行监听。之后就可以调用ngx_init_cycle来初始化ngx_cycle结构体，这个结构体用来存储所有的连接，具体如下：
struct ngx_cycle_s {
void ****conf_ctx;//配置上下文数组(含所有模块)
ngx_pool_t *pool;//内存池
ngx_log_t *log;//日志
ngx_log_t new_log;
ngx_connection_t **files;//连接文件
ngx_connection_t *free_connections;//空闲连接
ngx_uint_t free_connection_n;//空闲连接数
ngx_queue_t reusable_connections_queue;////再利用连接队列
ngx_array_t listening;//监听数组
ngx_array_t paths;//路径数组
ngx_list_t open_files;//打开文件链表
ngx_list_t shared_memory;//共享内存链表
ngx_uint_t connection_n;//连接个数
ngx_uint_t files_n;//打开文件个数
ngx_connection_t *connections;
ngx_event_t *read_events;//读事件
ngx_event_t *write_events;//写事件
ngx_cycle_t *old_cycle;
ngx_str_t conf_file;//配置文件
ngx_str_t conf_param;//配置参数
ngx_str_t conf_prefix;//配置前缀
ngx_str_t prefix;//前缀
ngx_str_t lock_file;//锁文件
ngx_str_t hostname;
调用ngx_init_signals来注册信号。
//信号种类
#define NGX_PROCESS_SINGLE 0
#define NGX_PROCESS_MASTER 1
#define NGX_PROCESS_SIGNALLER 2
#define NGX_PROCESS_WORKER 3
#define NGX_PROCESS_HELPER 4
在进入处理之前，还要调用ngx_create_pidfile来记录进程id。最后，根据接收到的信号，来判断调用ngx_single_process_cycle还是ngx_master_process_cycle（master-worker模式）。
if (ngx_process == NGX_PROCESS_SINGLE) {
ngx_single_process_cycle(cycle);
} else {
ngx_master_process_cycle(cycle);
}
其中，守护进程函数为ngx_daemon，位于src/os/unix/Ngx_daemon.c
//daemon
ngx_int_t
ngx_daemon(ngx_log_t *log)
{
int fd;
switch (fork()) {
case -:
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "fork() failed");
return NGX_ERROR;
case :
breakdefault:
exit();
} ngx_pid = ngx_getpid();//取得进程识别码 if (setsid() == -) { //子进程将重新获得一个新的会话(session)id
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "setsid() failed");
return NGX_ERROR;
} umask(); fd = open("/dev/null", O_RDWR);
if (fd == -) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
"open(\"/dev/null\") failed");
return NGX_ERROR;
} if (dup2(fd, STDIN_FILENO) == -) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "dup2(STDIN) failed");
return NGX_ERROR;
} if (dup2(fd, STDOUT_FILENO) == -) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "dup2(STDOUT) failed");
return NGX_ERROR;
} #if 0
if (dup2(fd, STDERR_FILENO) == -) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "dup2(STDERR) failed");
return NGX_ERROR;
}
#endif if (fd > STDERR_FILENO) {
if (close(fd) == -) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "close() failed");
return NGX_ERROR;
}
}
return NGX_OK;
}
参考
http://blog.xiuwz.com/2011/11/29/nginx-pcre-conflict/
http://blog.csdn.net/liuhongxiangm/article/details/8107613
http://blog.csdn.net/livelylittlefish/article/details/7243718