text: 
  /*
   * Copyright (C) Igor Sysoev
   * Copyright (C) Nginx, Inc.
   */
  
  
  #include <ngx_config.h>
  #include <ngx_core.h>
  #include <nginx.h>
  
  
  static void ngx_show_version_info(void);
  static ngx_int_t ngx_add_inherited_sockets(ngx_cycle_t *cycle);
  static void ngx_cleanup_environment(void *data);
  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 char *ngx_load_module(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
  #if (NGX_HAVE_DLOPEN)
  static void ngx_unload_module(void *data);
  #endif
  
  
  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, 0 }
  };
  
  
  static ngx_command_t  ngx_core_commands[] = {
  
      { ngx_string("daemon"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG,
        ngx_conf_set_flag_slot,
        0,
        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,
        0,
        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,
        0,
        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,
        0,
        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,
        0,
        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,
        0,
        0,
        NULL },
  
      { ngx_string("debug_points"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_enum_slot,
        0,
        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,
        0,
        0,
        NULL },
  
      { ngx_string("worker_priority"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_set_priority,
        0,
        0,
        NULL },
  
      { ngx_string("worker_cpu_affinity"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_1MORE,
        ngx_set_cpu_affinity,
        0,
        0,
        NULL },
  
      { ngx_string("worker_rlimit_nofile"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_num_slot,
        0,
        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,
        0,
        offsetof(ngx_core_conf_t, rlimit_core),
        NULL },
  
      { ngx_string("worker_shutdown_timeout"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_msec_slot,
        0,
        offsetof(ngx_core_conf_t, shutdown_timeout),
        NULL },
  
      { ngx_string("working_directory"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_conf_set_str_slot,
        0,
        offsetof(ngx_core_conf_t, working_directory),
        NULL },
  
      { ngx_string("env"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_set_env,
        0,
        0,
        NULL },
  
      { ngx_string("load_module"),
        NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
        ngx_load_module,
        0,
        0,
        NULL },
  
        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
  };
  
  
  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_error_log;
  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_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;
      }
  
  	// 主要用于解析命令行中的参数，例如：./nginx -s stop|start|restart
      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;
  	// 初始化并更新时间，如全局变量ngx_cached_time
      ngx_time_init();
  
  #if (NGX_PCRE)
      ngx_regex_init();
  #endif
  
      ngx_pid = ngx_getpid();
      ngx_parent = ngx_getppid();
  	// 初始化日志，并得到日志的文件句柄ngx_log_file.fd
      log = ngx_log_init(ngx_prefix, ngx_error_log);
      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;
  	
  	// 创建一个大小为 1024 的内存池
      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;
      }
  	// 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()
       */
  	// 初始化一致性hash表，主要作用是加快查询
      if (ngx_crc32_table_init() != NGX_OK) {
          return 1;
      }
  
      /*
       * ngx_slab_sizes_init() requires ngx_pagesize set in ngx_os_init()
       */
  
      ngx_slab_sizes_init();
  
      if (ngx_add_inherited_sockets(&init_cycle) != NGX_OK) {
          return 1;
      }
  	// 对模块进行编号处理
      if (ngx_preinit_modules() != NGX_OK) {
          return 1;
      }
  	// 完成全局变量cycle的初始化
      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;
      }
  	
      // 如果有信号，则进入ngx_signal_process方法。例如：例如./nginx -s stop,则处理Nginx的停止信号
      if (ngx_signal) {
          return ngx_signal_process(cycle, ngx_signal);
      }
  
      ngx_os_status(cycle->log);
  
      ngx_cycle = cycle;
  
      // 得到核心模块ngx_core_conf_t的配置文件指针
      // ngx_get_conf(conf_ctx, module)  conf_ctx[module.index]
      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;
  }
  
  
  static void
  ngx_show_version_info(void)
  {
      ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);
  
      if (ngx_show_help) {
          ngx_write_stderr(
              "Usage: nginx [-?hvVtTq] [-s signal] [-p prefix]" NGX_LINEFEED
              "             [-e filename] [-c filename] [-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
              "  -e filename   : set error log file (default: "
  #ifdef NGX_ERROR_LOG_STDERR
                                 "stderr)" NGX_LINEFEED
  #else
                                 NGX_ERROR_LOG_PATH ")" 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 (ngx_strcmp(ngx_ssl_version(), OPENSSL_VERSION_TEXT) == 0) {
              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) ngx_ssl_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);
      }
  }
  
  
  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, 0,
                    "using inherited sockets from \"%s\"", inherited);
  
      if (ngx_array_init(&cycle->listening, cycle->pool, 10,
                         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, 0,
                                "invalid socket number \"%s\" in " NGINX_VAR
                                " environment variable, ignoring the rest"
                                " of the variable", v);
                  break;
              }
  
              v = p + 1;
  
              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;
              ls->inherited = 1;
          }
      }
  
      if (v != p) {
          ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                        "invalid socket number \"%s\" in " NGINX_VAR
                        " environment variable, ignoring", v);
      }
  
      ngx_inherited = 1;
  
      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;
      ngx_pool_cleanup_t   *cln;
  
      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 = 0; i < ccf->env.nelts; i++) {
          if (ngx_strcmp(var[i].data, "TZ") == 0
              || ngx_strncmp(var[i].data, "TZ=", 3) == 0)
          {
              goto tz_found;
          }
      }
  
      var = ngx_array_push(&ccf->env);
      if (var == NULL) {
          return NULL;
      }
  
      var->len = 2;
      var->data = (u_char *) "TZ";
  
      var = ccf->env.elts;
  
  tz_found:
  
      n = 0;
  
      for (i = 0; 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) == 0
                  && (*p)[var[i].len] == '=')
              {
                  n++;
                  break;
              }
          }
      }
  
      if (last) {
          env = ngx_alloc((*last + n + 1) * sizeof(char *), cycle->log);
          if (env == NULL) {
              return NULL;
          }
  
          *last = n;
  
      } else {
          cln = ngx_pool_cleanup_add(cycle->pool, 0);
          if (cln == NULL) {
              return NULL;
          }
  
          env = ngx_alloc((n + 1) * sizeof(char *), cycle->log);
          if (env == NULL) {
              return NULL;
          }
  
          cln->handler = ngx_cleanup_environment;
          cln->data = env;
      }
  
      n = 0;
  
      for (i = 0; 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) == 0
                  && (*p)[var[i].len] == '=')
              {
                  env[n++] = *p;
                  break;
              }
          }
      }
  
      env[n] = NULL;
  
      if (last == NULL) {
          ccf->environment = env;
          environ = env;
      }
  
      return env;
  }
  
  
  static void
  ngx_cleanup_environment(void *data)
  {
      char  **env = data;
  
      if (environ == env) {
  
          /*
           * if the environment is still used, as it happens on exit,
           * the only option is to leak it
           */
  
          return;
      }
  
      ngx_free(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[0];
      ctx.name = "new binary process";
      ctx.argv = argv;
  
      n = 2;
      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 + 1) + 2,
                      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 = 0; 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, 0, "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[0]);
  
          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[0]);
          }
      }
  
      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 = 1; i < argc; i++) {
  
          p = (u_char *) argv[i];
  
          if (*p++ != '-') {
              ngx_log_stderr(0, "invalid option: \"%s\"", argv[i]);
              return NGX_ERROR;
          }
  
          while (*p) {
  
              switch (*p++) {
  
              case '?':
              case 'h':
                  ngx_show_version = 1;
                  ngx_show_help = 1;
                  break;
  
              case 'v':
                  ngx_show_version = 1;
                  break;
  
              case 'V':
                  ngx_show_version = 1;
                  ngx_show_configure = 1;
                  break;
  
              case 't':
                  ngx_test_config = 1;
                  break;
  
              case 'T':
                  ngx_test_config = 1;
                  ngx_dump_config = 1;
                  break;
  
              case 'q':
                  ngx_quiet_mode = 1;
                  break;
  
              case 'p':
                  if (*p) {
                      ngx_prefix = p;
                      goto next;
                  }
  
                  if (argv[++i]) {
                      ngx_prefix = (u_char *) argv[i];
                      goto next;
                  }
  
                  ngx_log_stderr(0, "option \"-p\" requires directory name");
                  return NGX_ERROR;
  
              case 'e':
                  if (*p) {
                      ngx_error_log = p;
  
                  } else if (argv[++i]) {
                      ngx_error_log = (u_char *) argv[i];
  
                  } else {
                      ngx_log_stderr(0, "option \"-e\" requires file name");
                      return NGX_ERROR;
                  }
  
                  if (ngx_strcmp(ngx_error_log, "stderr") == 0) {
                      ngx_error_log = (u_char *) "";
                  }
  
                  goto next;
  
              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(0, "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(0, "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(0, "option \"-s\" requires parameter");
                      return NGX_ERROR;
                  }
  
                  if (ngx_strcmp(ngx_signal, "stop") == 0
                      || ngx_strcmp(ngx_signal, "quit") == 0
                      || ngx_strcmp(ngx_signal, "reopen") == 0
                      || ngx_strcmp(ngx_signal, "reload") == 0)
                  {
                      ngx_process = NGX_PROCESS_SIGNALLER;
                      goto next;
                  }
  
                  ngx_log_stderr(0, "invalid option: \"-s %s\"", ngx_signal);
                  return NGX_ERROR;
  
              default:
                  ngx_log_stderr(0, "invalid option: \"%c\"", *(p - 1));
                  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 + 1) * sizeof(char *), cycle->log);
      if (ngx_argv == NULL) {
          return NGX_ERROR;
      }
  
      for (i = 0; i < argc; i++) {
          len = ngx_strlen(argv[i]) + 1;
  
          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 - 1])) {
              p = ngx_pnalloc(cycle->pool, len + 1);
              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) == 0) {
              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, 0) != NGX_OK) {
          return NGX_ERROR;
      }
  
      for (p = cycle->conf_file.data + cycle->conf_file.len - 1;
           p > cycle->conf_file.data;
           p--)
      {
          if (ngx_path_separator(*p)) {
              cycle->conf_prefix.len = p - cycle->conf_file.data + 1;
              cycle->conf_prefix.data = cycle->conf_file.data;
              break;
          }
      }
  
      if (ngx_error_log) {
          cycle->error_log.len = ngx_strlen(ngx_error_log);
          cycle->error_log.data = ngx_error_log;
  
      } else {
          ngx_str_set(&cycle->error_log, NGX_ERROR_LOG_PATH);
      }
  
      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_auto = 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->shutdown_timeout = 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->user = (ngx_uid_t) NGX_CONF_UNSET_UINT;
      ccf->group = (ngx_gid_t) NGX_CONF_UNSET_UINT;
  
      if (ngx_array_init(&ccf->env, cycle->pool, 1, 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, 1);
      ngx_conf_init_value(ccf->master, 1);
      ngx_conf_init_msec_value(ccf->timer_resolution, 0);
      ngx_conf_init_msec_value(ccf->shutdown_timeout, 0);
  
      ngx_conf_init_value(ccf->worker_processes, 1);
      ngx_conf_init_value(ccf->debug_points, 0);
  
  #if (NGX_HAVE_CPU_AFFINITY)
  
      if (!ccf->cpu_affinity_auto
          && ccf->cpu_affinity_n
          && ccf->cpu_affinity_n != 1
          && ccf->cpu_affinity_n != (ngx_uint_t) ccf->worker_processes)
      {
          ngx_log_error(NGX_LOG_WARN, cycle->log, 0,
                        "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 (ccf->pid.len == 0) {
          ngx_str_set(&ccf->pid, NGX_PID_PATH);
      }
  
      if (ngx_conf_full_name(cycle, &ccf->pid, 0) != 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() == 0) {
          struct group   *grp;
          struct passwd  *pwd;
  
          ngx_set_errno(0);
          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(0);
          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 == 0) {
          ngx_str_set(&ccf->lock_file, NGX_LOCK_PATH);
      }
  
      if (ngx_conf_full_name(cycle, &ccf->lock_file, 0) != 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)
                 != 0)
          {
              ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                            "\"lock_file\" could not be changed, ignored");
          }
  
          cycle->lock_file.len = lock_file.len + 1;
          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 + 1;
          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, 0,
                         "\"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() != 0) {
          ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                             "the \"user\" directive makes sense only "
                             "if the master process runs "
                             "with super-user privileges, ignored");
          return NGX_CONF_OK;
      }
  
      value = cf->args->elts;
  
      ccf->username = (char *) value[1].data;
  
      ngx_set_errno(0);
      pwd = getpwnam((const char *) value[1].data);
      if (pwd == NULL) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                             "getpwnam(\"%s\") failed", value[1].data);
          return NGX_CONF_ERROR;
      }
  
      ccf->user = pwd->pw_uid;
  
      group = (char *) ((cf->args->nelts == 2) ? value[1].data : value[2].data);
  
      ngx_set_errno(0);
      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[1];
  
      for (i = 0; i < value[1].len; i++) {
  
          if (value[1].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 != 0) {
          return "is duplicate";
      }
  
      value = cf->args->elts;
  
      if (value[1].data[0] == '-') {
          n = 1;
          minus = 1;
  
      } else if (value[1].data[0] == '+') {
          n = 1;
          minus = 0;
  
      } else {
          n = 0;
          minus = 0;
      }
  
      ccf->priority = ngx_atoi(&value[1].data[n], value[1].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, *p;
      ngx_str_t        *value;
      ngx_uint_t        i, n;
      ngx_cpuset_t     *mask;
  
      if (ccf->cpu_affinity) {
          return "is duplicate";
      }
  
      mask = ngx_palloc(cf->pool, (cf->args->nelts - 1) * sizeof(ngx_cpuset_t));
      if (mask == NULL) {
          return NGX_CONF_ERROR;
      }
  
      ccf->cpu_affinity_n = cf->args->nelts - 1;
      ccf->cpu_affinity = mask;
  
      value = cf->args->elts;
  
      if (ngx_strcmp(value[1].data, "auto") == 0) {
  
          if (cf->args->nelts > 3) {
              ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                 "invalid number of arguments in "
                                 "\"worker_cpu_affinity\" directive");
              return NGX_CONF_ERROR;
          }
  
          ccf->cpu_affinity_auto = 1;
  
          CPU_ZERO(&mask[0]);
          for (i = 0; i < (ngx_uint_t) ngx_min(ngx_ncpu, CPU_SETSIZE); i++) {
              CPU_SET(i, &mask[0]);
          }
  
          n = 2;
  
      } else {
          n = 1;
      }
  
      for ( /* void */ ; n < cf->args->nelts; n++) {
  
          if (value[n].len > CPU_SETSIZE) {
              ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "\"worker_cpu_affinity\" supports up to %d CPUs only",
                           CPU_SETSIZE);
              return NGX_CONF_ERROR;
          }
  
          i = 0;
          CPU_ZERO(&mask[n - 1]);
  
          for (p = value[n].data + value[n].len - 1;
               p >= value[n].data;
               p--)
          {
              ch = *p;
  
              if (ch == ' ') {
                  continue;
              }
  
              i++;
  
              if (ch == '0') {
                  continue;
              }
  
              if (ch == '1') {
                  CPU_SET(i - 1, &mask[n - 1]);
                  continue;
              }
  
              ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "invalid character \"%c\" in \"worker_cpu_affinity\"",
                            ch);
              return NGX_CONF_ERROR;
          }
      }
  
  #else
  
      ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                         "\"worker_cpu_affinity\" is not supported "
                         "on this platform, ignored");
  #endif
  
      return NGX_CONF_OK;
  }
  
  
  ngx_cpuset_t *
  ngx_get_cpu_affinity(ngx_uint_t n)
  {
  #if (NGX_HAVE_CPU_AFFINITY)
      ngx_uint_t        i, j;
      ngx_cpuset_t     *mask;
      ngx_core_conf_t  *ccf;
  
      static ngx_cpuset_t  result;
  
      ccf = (ngx_core_conf_t *) ngx_get_conf(ngx_cycle->conf_ctx,
                                             ngx_core_module);
  
      if (ccf->cpu_affinity == NULL) {
          return NULL;
      }
  
      if (ccf->cpu_affinity_auto) {
          mask = &ccf->cpu_affinity[ccf->cpu_affinity_n - 1];
  
          for (i = 0, j = n; /* void */ ; i++) {
  
              if (CPU_ISSET(i % CPU_SETSIZE, mask) && j-- == 0) {
                  break;
              }
  
              if (i == CPU_SETSIZE && j == n) {
                  /* empty mask */
                  return NULL;
              }
  
              /* void */
          }
  
          CPU_ZERO(&result);
          CPU_SET(i % CPU_SETSIZE, &result);
  
          return &result;
      }
  
      if (ccf->cpu_affinity_n > n) {
          return &ccf->cpu_affinity[n];
      }
  
      return &ccf->cpu_affinity[ccf->cpu_affinity_n - 1];
  
  #else
  
      return NULL;
  
  #endif
  }
  
  
  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 = cf->args->elts;
  
      if (ngx_strcmp(value[1].data, "auto") == 0) {
          ccf->worker_processes = ngx_ncpu;
          return NGX_CONF_OK;
      }
  
      ccf->worker_processes = ngx_atoi(value[1].data, value[1].len);
  
      if (ccf->worker_processes == NGX_ERROR) {
          return "invalid value";
      }
  
      return NGX_CONF_OK;
  }
  
  
  static char *
  ngx_load_module(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
  {
  #if (NGX_HAVE_DLOPEN)
      void                *handle;
      char               **names, **order;
      ngx_str_t           *value, file;
      ngx_uint_t           i;
      ngx_module_t        *module, **modules;
      ngx_pool_cleanup_t  *cln;
  
      if (cf->cycle->modules_used) {
          return "is specified too late";
      }
  
      value = cf->args->elts;
  
      file = value[1];
  
      if (ngx_conf_full_name(cf->cycle, &file, 0) != NGX_OK) {
          return NGX_CONF_ERROR;
      }
  
      cln = ngx_pool_cleanup_add(cf->cycle->pool, 0);
      if (cln == NULL) {
          return NGX_CONF_ERROR;
      }
  
      handle = ngx_dlopen(file.data);
      if (handle == NULL) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                             ngx_dlopen_n " \"%s\" failed (%s)",
                             file.data, ngx_dlerror());
          return NGX_CONF_ERROR;
      }
  
      cln->handler = ngx_unload_module;
      cln->data = handle;
  
      modules = ngx_dlsym(handle, "ngx_modules");
      if (modules == NULL) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                             ngx_dlsym_n " \"%V\", \"%s\" failed (%s)",
                             &value[1], "ngx_modules", ngx_dlerror());
          return NGX_CONF_ERROR;
      }
  
      names = ngx_dlsym(handle, "ngx_module_names");
      if (names == NULL) {
          ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                             ngx_dlsym_n " \"%V\", \"%s\" failed (%s)",
                             &value[1], "ngx_module_names", ngx_dlerror());
          return NGX_CONF_ERROR;
      }
  
      order = ngx_dlsym(handle, "ngx_module_order");
  
      for (i = 0; modules[i]; i++) {
          module = modules[i];
          module->name = names[i];
  
          if (ngx_add_module(cf, &file, module, order) != NGX_OK) {
              return NGX_CONF_ERROR;
          }
  
          ngx_log_debug2(NGX_LOG_DEBUG_CORE, cf->log, 0, "module: %s i:%ui",
                         module->name, module->index);
      }
  
      return NGX_CONF_OK;
  
  #else
  
      ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                         "\"load_module\" is not supported "
                         "on this platform");
      return NGX_CONF_ERROR;
  
  #endif
  }
  
  
  #if (NGX_HAVE_DLOPEN)
  
  static void
  ngx_unload_module(void *data)
  {
      void  *handle = data;
  
      if (ngx_dlclose(handle) != 0) {
          ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
                        ngx_dlclose_n " failed (%s)", ngx_dlerror());
      }
  }
  
  #endif
  