Nginx源码阅读(ngx_cycle_t)

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/* 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;  /* unsigned  log_use_stderr:1; */    ngx_connection_t        **files;    ngx_connection_t         *free_connections;    ngx_uint_t                free_connection_n;    ngx_module_t            **modules;    ngx_uint_t                modules_n;    ngx_uint_t                modules_used;    /* unsigned  modules_used:1; */    ngx_queue_t               reusable_connections_queue;    ngx_array_t               listening;    ngx_array_t               paths;    ngx_array_t               config_dump;    ngx_list_t                open_files;    ngx_list_t                shared_memory;    ngx_uint_t                connection_n;    ngx_uint_t                files_n;    // 以下三个数组的长度都是connection_n,一个连接对应一个读事件和一个写事件    ngx_connection_t         *connections; // 连接数组    ngx_event_t              *read_events; // 读事件数组    ngx_event_t              *write_events; // 写事件数组    ngx_cycle_t              *old_cycle;    ngx_str_t                 conf_file; // nginx配置文件路径,/usr/local/nginx/conf/nginx.conf    ngx_str_t                 conf_param;    ngx_str_t                 conf_prefix; // nginx配置文件目录,/usr/local/nginx/conf/    ngx_str_t                 prefix; // nginx目录,/usr/local/nginx/    ngx_str_t                 lock_file;    ngx_str_t                 hostname; // 在ngx_init_cycle()中调用gethostname()初始化};
/* src/core/ngx_cycle.c */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();    /* force localtime update with a new timezone */    tp = ngx_timeofday();    tp->sec = 0;    ngx_time_update();    // 初始化pool、log、old_cycle    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;    // 初始化conf_prefix    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;    }    // 初始化prefix    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;    }    // 初始化conf_file    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);    // 初始化conf_param    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;    }    // 初始化paths数组    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;    // 初始化config_dump数组    if (ngx_array_init(&cycle->config_dump, pool, 1, sizeof(ngx_conf_dump_t))        != NGX_OK)    {        ngx_destroy_pool(pool);        return NULL;    }    // 初始化open_files链表    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;    }    // 初始化shared_memory链表    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;    }    // 初始化listening数组    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;    // 初始化reusable_connections_queue队列    ngx_queue_init(&cycle->reusable_connections_queue);    // 为conf_ctx数组分配内存    cycle->conf_ctx = ngx_pcalloc(pool, ngx_max_module * sizeof(void *));    if (cycle->conf_ctx == NULL) {        ngx_destroy_pool(pool);        return NULL;    }    // 初始化hostname    if (gethostname(hostname, NGX_MAXHOSTNAMELEN) == -1) {        ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "gethostname() failed");        ngx_destroy_pool(pool);        return NULL;    }    /* on Linux gethostname() silently truncates name that does not fit */    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);    // 初始化modules数组,copy ngx_modules to modules    if (ngx_cycle_modules(cycle) != NGX_OK) {        ngx_destroy_pool(pool);        return NULL;    }    // 调用create_conf()创建核心模块的配置结构体,并把该结构体的地址保存到conf_ctx数组中    for (i = 0; cycle->modules[i]; i++) {        if (cycle->modules[i]->type != NGX_CORE_MODULE) {            continue;        }        module = cycle->modules[i]->ctx;        if (module->create_conf) {            rv = module->create_conf(cycle);            if (rv == NULL) {                ngx_destroy_pool(pool);                return NULL;            }            cycle->conf_ctx[cycle->modules[i]->index] = rv;        }    }    // 初始化conf,一个类型为ngx_conf_t的结构体    senv = environ;    ngx_memzero(&conf, sizeof(ngx_conf_t));    /* STUB: init array ? */    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    // 解析配置文件    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);    }    // 调用init_conf()初始化核心模块的配置结构体    for (i = 0; cycle->modules[i]; i++) {        if (cycle->modules[i]->type != NGX_CORE_MODULE) {            continue;        }        module = cycle->modules[i]->ctx;        if (module->init_conf) {            if (module->init_conf(cycle,                                  cycle->conf_ctx[cycle->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)) {        /*         * we do not create the pid file in the first ngx_init_cycle() call         * because we need to write the demonized process pid         */        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)        {            /* new pid file name */            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;    }    /* open the new files */    part = &cycle->open_files.part;    file = part->elts;    for (i = 0; /* void */ ; 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;    /* create shared memory */    part = &cycle->shared_memory.part;    shm_zone = part->elts;    for (i = 0; /* void */ ; 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; /* void */ ; 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].noreuse)            {                shm_zone[i].shm.addr = oshm_zone[n].shm.addr;#if (NGX_WIN32)                shm_zone[i].shm.handle = oshm_zone[n].shm.handle;#endif                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;    }    /* handle the listening sockets */    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 (ls[i].remain) {                    continue;                }                if (ls[i].type != nls[n].type) {                    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)                    /*                     * FreeBSD, except the most recent versions,                     * could not remove accept filter                     */                    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#if (NGX_HAVE_REUSEPORT)                    if (nls[n].reuseport && !ls[i].reuseport) {                        nls[n].add_reuseport = 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);    }    /* commit the new cycle configuration */    if (!ngx_use_stderr) {        (void) ngx_log_redirect_stderr(cycle);    }    pool->log = cycle->log;    // 调用各个模块的init_module,实际上只调用了ngx_event_core_module的ngx_event_module_init()    if (ngx_init_modules(cycle) != NGX_OK) {        /* fatal */        exit(1);    }    /* close and delete stuff that lefts from an old cycle */    /* free the unnecessary shared memory */    opart = &old_cycle->shared_memory.part;    oshm_zone = opart->elts;    for (i = 0; /* void */ ; 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; /* void */ ; 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:    /* close the unnecessary listening sockets */    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    }    /* close the unnecessary open files */    part = &old_cycle->open_files.part;    file = part->elts;    for (i = 0; /* void */ ; 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)) {        /*         * perl_destruct() frees environ, if it is not the same as it was at         * perl_construct() time, therefore we save the previous cycle         * environment before ngx_conf_parse() where it will be changed.         */        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;        }    }    /* rollback the new cycle configuration */    part = &cycle->open_files.part;    file = part->elts;    for (i = 0; /* void */ ; 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;}

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