# Nginx 启动初始化过程 ## Nginx 启动过程 Nginx 的启动初始化由 main 函数完成，该函数是整个 Nginx 的入口，该函数完成 Nginx 启动初始化任务，也是所有功能模块的入口。Nginx 的初始化工作主要是一个类型为 ngx\_cycle\_t 类型的全局变量。main 函数定义在文件：[src/​core/​nginx.c](http://lxr.nginx.org/source/src/core/nginx.c) Nginx 启动过程如下。 * 调用 ngx\_get\_options() 解析命令参数； * 显示版本号与帮助信息； * 调用 ngx\_time\_init() 初始化并更新时间； * 调用 ngx\_log\_init() 初始化日志； * 创建全局变量 init\_cycle 的内存池 pool； * 调用 ngx\_save\_argv() 保存命令行参数至全局变量ngx\_os\_argv、ngx\_argc、ngx\_argv 中； * 调用 ngx\_process\_options() 初始化 init\_cycle 的 prefix, conf\_prefix, conf\_file, conf\_param 等字段； * 调用 ngx\_os\_init() 初始化系统相关变量； * 调用 ngx\_crc32\_table\_init() 初始化CRC表； * 调用 ngx\_add\_inherited\_sockets() 继承 sockets； * 通过环境变量 NGINX 完成 socket 的继承，将其保存在全局变量 init\_cycle 的 listening 数组中； * 初始化每个模块 module 的index，并计算 ngx\_max\_module； * 调用 ngx\_init\_cycle() 进行初始化全局变量 init\_cycle，这个步骤非常重要； * 调用 ngx\_signal\_process() 处理进程信号； * 调用 ngx\_init\_signals() 注册相关信号； * 若无继承 sockets，则调用 ngx\_daemon() 创建守护进程，并设置其标志； * 调用 ngx\_create\_pidfile() 创建进程 ID 记录文件； * 进入进程处理： * 单进程工作模式； * 多进程工作模式，即 master-worker 多进程工作模式； ``` 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("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; } } 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; } #if (NGX_OPENSSL) ngx_ssl_init(log); #endif 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; } 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_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; } ``` ## ngx\_cycle\_t 变量初始化 ## ngx\_cycle\_t 结构体初始化 在初始化过程中，ngx\_cycle\_t 类型的全局变量最为重要，该类型结构定义如下：[src/​core/​ngx\_cycle.h](http://lxr.nginx.org/source/src/core/ngx_cycle.h) ``` struct ngx_cycle_s { void **conf_ctx; ngx_pool_t *pool; ngx_log_t *log; ngx_log_t new_log; ngx_uint_t log_use_stderr; ngx_connection_t **files; ngx_connection_t *free_connections; ngx_uint_t free_connection_n; ngx_queue_t reusable_connections_queue; ngx_array_t listening; ngx_array_t paths; ngx_list_t open_files; ngx_list_t shared_memory; ngx_uint_t connection_n; ngx_uint_t files_n; ngx_connection_t *connections; ngx_event_t *read_events; ngx_event_t *write_events; ngx_cycle_t *old_cycle; ngx_str_t conf_file; ngx_str_t conf_param; ngx_str_t conf_prefix; ngx_str_t prefix; ngx_str_t lock_file; ngx_str_t hostname; }; ``` ## ngx\_init\_cycle() 初始化函数 该结构的初始化是通过函数 ngx\_init\_cycle() 完成的，该函数定义如下：[src/​core/​ngx\_cycle.c](http://lxr.nginx.org/source/src/core/ngx_cycle.c) ngx\_cycle\_t 结构全局变量初始化过程如下： * 更新时区与时间； * 创建内存池； * 分配 ngx\_cycle\_t 结构体内存，创建该结构的变量 cycle 并初始化； * 遍历所有 core模块，并调用该模块的 create\_conf() 函数； * 配置文件解析； * 遍历所有core模块，并调用core模块的init\_conf()函数； * 遍历 open\_files 链表中的每一个文件并打开； * 创建新的共享内存并初始化； * 遍历 listening 数组并打开所有侦听； * 提交新的 cycle 配置，并调用所有模块的init\_module； * 关闭或删除不被使用的在 old\_cycle 中的资源： * 释放多余的共享内存； * 关闭多余的侦听 sockets； * 关闭多余的打开文件； ``` ngx_cycle_t * ngx_init_cycle(ngx_cycle_t *old_cycle) { void *rv; char **senv, **env; ngx_uint_t i, n; ngx_log_t *log; ngx_time_t *tp; ngx_conf_t conf; ngx_pool_t *pool; ngx_cycle_t *cycle, **old; ngx_shm_zone_t *shm_zone, *oshm_zone; ngx_list_part_t *part, *opart; ngx_open_file_t *file; ngx_listening_t *ls, *nls; ngx_core_conf_t *ccf, *old_ccf; ngx_core_module_t *module; char hostname[NGX_MAXHOSTNAMELEN]; ngx_timezone_update(); tp = ngx_timeofday(); tp->sec = 0; ngx_time_update(); log = old_cycle->log; pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log); if (pool == NULL) { return NULL; } pool->log = log; cycle = ngx_pcalloc(pool, sizeof(ngx_cycle_t)); if (cycle == NULL) { ngx_destroy_pool(pool); return NULL; } cycle->pool = pool; cycle->log = log; cycle->old_cycle = old_cycle; cycle->conf_prefix.len = old_cycle->conf_prefix.len; cycle->conf_prefix.data = ngx_pstrdup(pool, &old_cycle->conf_prefix); if (cycle->conf_prefix.data == NULL) { ngx_destroy_pool(pool); return NULL; } cycle->prefix.len = old_cycle->prefix.len; cycle->prefix.data = ngx_pstrdup(pool, &old_cycle->prefix); if (cycle->prefix.data == NULL) { ngx_destroy_pool(pool); return NULL; } cycle->conf_file.len = old_cycle->conf_file.len; cycle->conf_file.data = ngx_pnalloc(pool, old_cycle->conf_file.len + 1); if (cycle->conf_file.data == NULL) { ngx_destroy_pool(pool); return NULL; } ngx_cpystrn(cycle->conf_file.data, old_cycle->conf_file.data, old_cycle->conf_file.len + 1); cycle->conf_param.len = old_cycle->conf_param.len; cycle->conf_param.data = ngx_pstrdup(pool, &old_cycle->conf_param); if (cycle->conf_param.data == NULL) { ngx_destroy_pool(pool); return NULL; } n = old_cycle->paths.nelts ? old_cycle->paths.nelts : 10; cycle->paths.elts = ngx_pcalloc(pool, n * sizeof(ngx_path_t *)); if (cycle->paths.elts == NULL) { ngx_destroy_pool(pool); return NULL; } cycle->paths.nelts = 0; cycle->paths.size = sizeof(ngx_path_t *); cycle->paths.nalloc = n; cycle->paths.pool = pool; if (old_cycle->open_files.part.nelts) { n = old_cycle->open_files.part.nelts; for (part = old_cycle->open_files.part.next; part; part = part->next) { n += part->nelts; } } else { n = 20; } if (ngx_list_init(&cycle->open_files, pool, n, sizeof(ngx_open_file_t)) != NGX_OK) { ngx_destroy_pool(pool); return NULL; } if (old_cycle->shared_memory.part.nelts) { n = old_cycle->shared_memory.part.nelts; for (part = old_cycle->shared_memory.part.next; part; part = part->next) { n += part->nelts; } } else { n = 1; } if (ngx_list_init(&cycle->shared_memory, pool, n, sizeof(ngx_shm_zone_t)) != NGX_OK) { ngx_destroy_pool(pool); return NULL; } n = old_cycle->listening.nelts ? old_cycle->listening.nelts : 10; cycle->listening.elts = ngx_pcalloc(pool, n * sizeof(ngx_listening_t)); if (cycle->listening.elts == NULL) { ngx_destroy_pool(pool); return NULL; } cycle->listening.nelts = 0; cycle->listening.size = sizeof(ngx_listening_t); cycle->listening.nalloc = n; cycle->listening.pool = pool; ngx_queue_init(&cycle->reusable_connections_queue); cycle->conf_ctx = ngx_pcalloc(pool, ngx_max_module * sizeof(void *)); if (cycle->conf_ctx == NULL) { ngx_destroy_pool(pool); return NULL; } if (gethostname(hostname, NGX_MAXHOSTNAMELEN) == -1) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "gethostname() failed"); ngx_destroy_pool(pool); return NULL; } hostname[NGX_MAXHOSTNAMELEN - 1] = '\0'; cycle->hostname.len = ngx_strlen(hostname); cycle->hostname.data = ngx_pnalloc(pool, cycle->hostname.len); if (cycle->hostname.data == NULL) { ngx_destroy_pool(pool); return NULL; } ngx_strlow(cycle->hostname.data, (u_char *) hostname, cycle->hostname.len); for (i = 0; ngx_modules[i]; i++) { if (ngx_modules[i]->type != NGX_CORE_MODULE) { continue; } module = ngx_modules[i]->ctx; if (module->create_conf) { rv = module->create_conf(cycle); if (rv == NULL) { ngx_destroy_pool(pool); return NULL; } cycle->conf_ctx[ngx_modules[i]->index] = rv; } } senv = environ; ngx_memzero(&conf, sizeof(ngx_conf_t)); conf.args = ngx_array_create(pool, 10, sizeof(ngx_str_t)); if (conf.args == NULL) { ngx_destroy_pool(pool); return NULL; } conf.temp_pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log); if (conf.temp_pool == NULL) { ngx_destroy_pool(pool); return NULL; } conf.ctx = cycle->conf_ctx; conf.cycle = cycle; conf.pool = pool; conf.log = log; conf.module_type = NGX_CORE_MODULE; conf.cmd_type = NGX_MAIN_CONF; #if 0 log->log_level = NGX_LOG_DEBUG_ALL; #endif if (ngx_conf_param(&conf) != NGX_CONF_OK) { environ = senv; ngx_destroy_cycle_pools(&conf); return NULL; } if (ngx_conf_parse(&conf, &cycle->conf_file) != NGX_CONF_OK) { environ = senv; ngx_destroy_cycle_pools(&conf); return NULL; } if (ngx_test_config && !ngx_quiet_mode) { ngx_log_stderr(0, "the configuration file %s syntax is ok", cycle->conf_file.data); } for (i = 0; ngx_modules[i]; i++) { if (ngx_modules[i]->type != NGX_CORE_MODULE) { continue; } module = ngx_modules[i]->ctx; if (module->init_conf) { if (module->init_conf(cycle, cycle->conf_ctx[ngx_modules[i]->index]) == NGX_CONF_ERROR) { environ = senv; ngx_destroy_cycle_pools(&conf); return NULL; } } } if (ngx_process == NGX_PROCESS_SIGNALLER) { return cycle; } ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module); if (ngx_test_config) { if (ngx_create_pidfile(&ccf->pid, log) != NGX_OK) { goto failed; } } else if (!ngx_is_init_cycle(old_cycle)) { old_ccf = (ngx_core_conf_t *) ngx_get_conf(old_cycle->conf_ctx, ngx_core_module); if (ccf->pid.len != old_ccf->pid.len || ngx_strcmp(ccf->pid.data, old_ccf->pid.data) != 0) { if (ngx_create_pidfile(&ccf->pid, log) != NGX_OK) { goto failed; } ngx_delete_pidfile(old_cycle); } } if (ngx_test_lockfile(cycle->lock_file.data, log) != NGX_OK) { goto failed; } if (ngx_create_paths(cycle, ccf->user) != NGX_OK) { goto failed; } if (ngx_log_open_default(cycle) != NGX_OK) { goto failed; } part = &cycle->open_files.part; file = part->elts; for (i = 0; ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; file = part->elts; i = 0; } if (file[i].name.len == 0) { continue; } file[i].fd = ngx_open_file(file[i].name.data, NGX_FILE_APPEND, NGX_FILE_CREATE_OR_OPEN, NGX_FILE_DEFAULT_ACCESS); ngx_log_debug3(NGX_LOG_DEBUG_CORE, log, 0, "log: %p %d \"%s\"", &file[i], file[i].fd, file[i].name.data); if (file[i].fd == NGX_INVALID_FILE) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, ngx_open_file_n " \"%s\" failed", file[i].name.data); goto failed; } #if !(NGX_WIN32) if (fcntl(file[i].fd, F_SETFD, FD_CLOEXEC) == -1) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "fcntl(FD_CLOEXEC) \"%s\" failed", file[i].name.data); goto failed; } #endif } cycle->log = &cycle->new_log; pool->log = &cycle->new_log; part = &cycle->shared_memory.part; shm_zone = part->elts; for (i = 0; ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; shm_zone = part->elts; i = 0; } if (shm_zone[i].shm.size == 0) { ngx_log_error(NGX_LOG_EMERG, log, 0, "zero size shared memory zone \"%V\"", &shm_zone[i].shm.name); goto failed; } shm_zone[i].shm.log = cycle->log; opart = &old_cycle->shared_memory.part; oshm_zone = opart->elts; for (n = 0; ; n++) { if (n >= opart->nelts) { if (opart->next == NULL) { break; } opart = opart->next; oshm_zone = opart->elts; n = 0; } if (shm_zone[i].shm.name.len != oshm_zone[n].shm.name.len) { continue; } if (ngx_strncmp(shm_zone[i].shm.name.data, oshm_zone[n].shm.name.data, shm_zone[i].shm.name.len) != 0) { continue; } if (shm_zone[i].tag == oshm_zone[n].tag && shm_zone[i].shm.size == oshm_zone[n].shm.size) { shm_zone[i].shm.addr = oshm_zone[n].shm.addr; if (shm_zone[i].init(&shm_zone[i], oshm_zone[n].data) != NGX_OK) { goto failed; } goto shm_zone_found; } ngx_shm_free(&oshm_zone[n].shm); break; } if (ngx_shm_alloc(&shm_zone[i].shm) != NGX_OK) { goto failed; } if (ngx_init_zone_pool(cycle, &shm_zone[i]) != NGX_OK) { goto failed; } if (shm_zone[i].init(&shm_zone[i], NULL) != NGX_OK) { goto failed; } shm_zone_found: continue; } if (old_cycle->listening.nelts) { ls = old_cycle->listening.elts; for (i = 0; i < old_cycle->listening.nelts; i++) { ls[i].remain = 0; } nls = cycle->listening.elts; for (n = 0; n < cycle->listening.nelts; n++) { for (i = 0; i < old_cycle->listening.nelts; i++) { if (ls[i].ignore) { continue; } if (ngx_cmp_sockaddr(nls[n].sockaddr, nls[n].socklen, ls[i].sockaddr, ls[i].socklen, 1) == NGX_OK) { nls[n].fd = ls[i].fd; nls[n].previous = &ls[i]; ls[i].remain = 1; if (ls[i].backlog != nls[n].backlog) { nls[n].listen = 1; } #if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER) nls[n].deferred_accept = ls[i].deferred_accept; if (ls[i].accept_filter && nls[n].accept_filter) { if (ngx_strcmp(ls[i].accept_filter, nls[n].accept_filter) != 0) { nls[n].delete_deferred = 1; nls[n].add_deferred = 1; } } else if (ls[i].accept_filter) { nls[n].delete_deferred = 1; } else if (nls[n].accept_filter) { nls[n].add_deferred = 1; } #endif #if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT) if (ls[i].deferred_accept && !nls[n].deferred_accept) { nls[n].delete_deferred = 1; } else if (ls[i].deferred_accept != nls[n].deferred_accept) { nls[n].add_deferred = 1; } #endif break; } } if (nls[n].fd == (ngx_socket_t) -1) { nls[n].open = 1; #if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER) if (nls[n].accept_filter) { nls[n].add_deferred = 1; } #endif #if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT) if (nls[n].deferred_accept) { nls[n].add_deferred = 1; } #endif } } } else { ls = cycle->listening.elts; for (i = 0; i < cycle->listening.nelts; i++) { ls[i].open = 1; #if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER) if (ls[i].accept_filter) { ls[i].add_deferred = 1; } #endif #if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT) if (ls[i].deferred_accept) { ls[i].add_deferred = 1; } #endif } } if (ngx_open_listening_sockets(cycle) != NGX_OK) { goto failed; } if (!ngx_test_config) { ngx_configure_listening_sockets(cycle); } if (!ngx_use_stderr) { (void) ngx_log_redirect_stderr(cycle); } pool->log = cycle->log; for (i = 0; ngx_modules[i]; i++) { if (ngx_modules[i]->init_module) { if (ngx_modules[i]->init_module(cycle) != NGX_OK) { exit(1); } } } opart = &old_cycle->shared_memory.part; oshm_zone = opart->elts; for (i = 0; ; i++) { if (i >= opart->nelts) { if (opart->next == NULL) { goto old_shm_zone_done; } opart = opart->next; oshm_zone = opart->elts; i = 0; } part = &cycle->shared_memory.part; shm_zone = part->elts; for (n = 0; ; n++) { if (n >= part->nelts) { if (part->next == NULL) { break; } part = part->next; shm_zone = part->elts; n = 0; } if (oshm_zone[i].shm.name.len == shm_zone[n].shm.name.len && ngx_strncmp(oshm_zone[i].shm.name.data, shm_zone[n].shm.name.data, oshm_zone[i].shm.name.len) == 0) { goto live_shm_zone; } } ngx_shm_free(&oshm_zone[i].shm); live_shm_zone: continue; } old_shm_zone_done: ls = old_cycle->listening.elts; for (i = 0; i < old_cycle->listening.nelts; i++) { if (ls[i].remain || ls[i].fd == (ngx_socket_t) -1) { continue; } if (ngx_close_socket(ls[i].fd) == -1) { ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno, ngx_close_socket_n " listening socket on %V failed", &ls[i].addr_text); } #if (NGX_HAVE_UNIX_DOMAIN) if (ls[i].sockaddr->sa_family == AF_UNIX) { u_char *name; name = ls[i].addr_text.data + sizeof("unix:") - 1; ngx_log_error(NGX_LOG_WARN, cycle->log, 0, "deleting socket %s", name); if (ngx_delete_file(name) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno, ngx_delete_file_n " %s failed", name); } } #endif } part = &old_cycle->open_files.part; file = part->elts; for (i = 0; ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; file = part->elts; i = 0; } if (file[i].fd == NGX_INVALID_FILE || file[i].fd == ngx_stderr) { continue; } if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, ngx_close_file_n " \"%s\" failed", file[i].name.data); } } ngx_destroy_pool(conf.temp_pool); if (ngx_process == NGX_PROCESS_MASTER || ngx_is_init_cycle(old_cycle)) { env = environ; environ = senv; ngx_destroy_pool(old_cycle->pool); cycle->old_cycle = NULL; environ = env; return cycle; } if (ngx_temp_pool == NULL) { ngx_temp_pool = ngx_create_pool(128, cycle->log); if (ngx_temp_pool == NULL) { ngx_log_error(NGX_LOG_EMERG, cycle->log, 0, "could not create ngx_temp_pool"); exit(1); } n = 10; ngx_old_cycles.elts = ngx_pcalloc(ngx_temp_pool, n * sizeof(ngx_cycle_t *)); if (ngx_old_cycles.elts == NULL) { exit(1); } ngx_old_cycles.nelts = 0; ngx_old_cycles.size = sizeof(ngx_cycle_t *); ngx_old_cycles.nalloc = n; ngx_old_cycles.pool = ngx_temp_pool; ngx_cleaner_event.handler = ngx_clean_old_cycles; ngx_cleaner_event.log = cycle->log; ngx_cleaner_event.data = &dumb; dumb.fd = (ngx_socket_t) -1; } ngx_temp_pool->log = cycle->log; old = ngx_array_push(&ngx_old_cycles); if (old == NULL) { exit(1); } *old = old_cycle; if (!ngx_cleaner_event.timer_set) { ngx_add_timer(&ngx_cleaner_event, 30000); ngx_cleaner_event.timer_set = 1; } return cycle; failed: if (!ngx_is_init_cycle(old_cycle)) { old_ccf = (ngx_core_conf_t *) ngx_get_conf(old_cycle->conf_ctx, ngx_core_module); if (old_ccf->environment) { environ = old_ccf->environment; } } part = &cycle->open_files.part; file = part->elts; for (i = 0; ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; file = part->elts; i = 0; } if (file[i].fd == NGX_INVALID_FILE || file[i].fd == ngx_stderr) { continue; } if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, ngx_close_file_n " \"%s\" failed", file[i].name.data); } } if (ngx_test_config) { ngx_destroy_cycle_pools(&conf); return NULL; } ls = cycle->listening.elts; for (i = 0; i < cycle->listening.nelts; i++) { if (ls[i].fd == (ngx_socket_t) -1 || !ls[i].open) { continue; } if (ngx_close_socket(ls[i].fd) == -1) { ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno, ngx_close_socket_n " %V failed", &ls[i].addr_text); } } ngx_destroy_cycle_pools(&conf); return NULL; } ``` 参考资料：\ 《 [nginx源码分析—启动流程](http://blog.csdn.net/livelylittlefish/article/details/7243718)》 《[Nginx启动初始化过程](http://www.alidata.org/archives/1148)》 --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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