用户工具

站点工具


about_ngx_1

Nginx源码分析 第一章 启动过程分析

作者:陈科

联系方式:chenke@dumpcache.com

转载请说明出处:http://www.dumpcache.com/wiki/doku.php?id=about_ngx_1

ngx的代码,离不开ngx_cycle_s和ngx_pool_s这两个核心数据结构,所以,我们先来分析下。

1.ngx_pool_t

ngx_pool_s是ngx的内存池,每个工作线程都会持有一个,我们来看它的结构:

struct ngx_pool_s {
    ngx_pool_data_t       d; //数据块
    size_t                max;  //小块内存的最大值
    ngx_pool_t           *current;//指向当前内存池
    ngx_chain_t          *chain;
    ngx_pool_large_t     *large; //分配大块内存用,即超过max的内存请求
    ngx_pool_cleanup_t   *cleanup;//挂载一些内存池释放的时候,同时释放的资源。
    ngx_log_t            *log;
};

接着我们来看ngx_pool_data_t的结构:

typedef struct {
    u_char               *last;//当前数据块分配结束位置
    u_char               *end; //数据块结束位置
    ngx_pool_t           *next;//链接到下一个内存池
    ngx_uint_t            failed; //统计该内存池不能满足分配请求的次数
} ngx_pool_data_t;

然后我们结合ngx_palloc方法来看一下内存池的分配原理:

void *
ngx_palloc(ngx_pool_t *pool, size_t size)
{
    u_char      *m;
    ngx_pool_t  *p;
 
    if (size <= pool->max) {
 
        p = pool->current;
 
        do {
            m = ngx_align_ptr(p->d.last, NGX_ALIGNMENT);
 
            if ((size_t) (p->d.end - m) >= size) {
                p->d.last = m + size;
 
                return m;
            }
 
            p = p->d.next;
 
        } while (p);
 
        return ngx_palloc_block(pool, size);
    }
 
    return ngx_palloc_large(pool, size);
}

这个过程分为3步:

1.假如申请的内存小于当前块剩余的空间,则直接在当前块中分配。

2.假如当前块空间不足,则调用ngx_palloc_block分配一个新块然后把新块链接到d.next中,然后分配数据。

3.假如申请的大小大于当前块的最大值,则直接调用ngx_palloc_large分配一个大块,并且链接到pool→large链表中

原理图如下:

2. ngx_cycle_t

接下来我们来看ngx_cycle_s这个数据结构,每个工作线程都会维护一个:

struct ngx_cycle_s {
    void                  ****conf_ctx;
    ngx_pool_t               *pool;//每个ngx_cycle维护一个ngx_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;//打开文件
    ngx_connection_t         *free_connections;//空闲连接
    ngx_uint_t                free_connection_n;
 
    ngx_queue_t               reusable_connections_queue;//连接队列
 
    ngx_array_t               listening;//监听socket
    ngx_array_t               paths;
    ngx_list_t                open_files;
    ngx_list_t                shared_memory;//共享内存
 
    ngx_uint_t                connection_n;
    ngx_uint_t                files_n;
 
    ngx_connection_t         *connections;//所有连接
    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;
    ngx_str_t                 conf_param;
    ngx_str_t                 conf_prefix;
    ngx_str_t                 prefix;
    ngx_str_t                 lock_file;
    ngx_str_t                 hostname;
};

3.工作进程模型初始化

最后,我们结合main函数来分析工作进程模型的初始化过程:

这里我仅介绍最主要的两个过程,不关心的部分将会忽略:

1.ngx_init_cycle

该函数比较长,主要步骤在注释中说明:

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];
 
    //1.更新timezone和time
    ngx_timezone_update();
 
    /* force localtime update with a new timezone */
 
    tp = ngx_timeofday();
    tp->sec = 0;
 
    ngx_time_update();
 
 
    log = old_cycle->log;
 
    //2.创建内存池
    pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log);
    if (pool == NULL) {
        return NULL;
    }
    pool->log = log;
 
    //3.给cycle指针分配内存
    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;
 
    //4.保存安装路径,配置文件,启动参数等
    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;
    }
 
    //5.初始化打开文件句柄
    if (ngx_list_init(&cycle->open_files, pool, n, sizeof(ngx_open_file_t))
        != NGX_OK)
    {
        ngx_destroy_pool(pool);
        return NULL;
    }
 
    //6.初始化共享内存
    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;
 
    //7.初始化连接队列
    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;
    }
 
   //8.保存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);
 
    //9.调用各NGX_CORE_MODULE的create_conf方法
    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));
    /* 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
 
    if (ngx_conf_param(&conf) != NGX_CONF_OK) {
        environ = senv;
        ngx_destroy_cycle_pools(&conf);
        return NULL;
    }
 
    //10.解析配置文件
    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);
    }
 
    //11.调用各NGX_CORE_MODULE的init_conf方法
 
    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)) {
 
        /*
         * 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;
    }
 
    //12.打开新的文件句柄
    /* 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;
 
    //13.创建共享内存
    /* 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].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;
    }
 
    //14.处理监听socket
    /* 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 (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
                    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
        }
    }
 
    //15.创建socket进行监听
    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;
    //16.调用各模块的init_module
    for (i = 0; ngx_modules[i]; i++) {
        if (ngx_modules[i]->init_module) {
            if (ngx_modules[i]->init_module(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;
}

2.ngx_master_process_cycle(cycle)

1.该函数通过调用ngx_start_worker_processes最终通过fork来创建work线程

2.ngx_start_cache_manager_processes

about_ngx_1.txt · 最后更改: 2018/10/14 15:31 (外部编辑)