コード例 #1
0
ファイル: ngx_event_mbedtls.c プロジェクト: sbagmeijer/nginx
ngx_int_t
ngx_ssl_init(ngx_log_t *log)
{
    static unsigned char  ctr_drbg_custom[] = "nginx-polarssl";
    entropy_context       entropy;
    int                   sslerr;

    /* Initialize the PRNG */

    entropy_init(&entropy);
    sslerr = ctr_drbg_init(&ngx_ctr_drbg, entropy_func, &entropy,
                           ctr_drbg_custom, ngx_strlen(ctr_drbg_custom));
    if (sslerr != 0) {
        ngx_mbedtls_error(NGX_LOG_EMERG, log, 0, sslerr,
                           "ctr_drbg_init() failed");
        return NGX_ERROR;
    }

#if (NGX_THREADS)
    ngx_ctr_drbg_mutex = ngx_mutex_init(log, 0);
    if (ngx_ctr_drbg_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

    return NGX_OK;
}
コード例 #2
0
ファイル: ngx_event.c プロジェクト: irontoolki/ironfox
static ngx_int_t
ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *ls;
    ngx_connection_t    *c, *next, *old;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

    if (ccf->master && ccf->worker_processes > 1 && ecf->accept_mutex) {
        ngx_use_accept_mutex = 1;
        ngx_accept_mutex_held = 0;
        ngx_accept_mutex_delay = ecf->accept_mutex_delay;

    } else {
        ngx_use_accept_mutex = 0;
    }

#if (NGX_WIN32)

    /*
     * disable accept mutex on win32 as it may cause deadlock if
     * grabbed by a process which can't accept connections
     */

    ngx_use_accept_mutex = 0;

#endif

#if (NGX_THREADS)
    ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0);
    if (ngx_posted_events_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        if (ngx_modules[m]->ctx_index != ecf->use) {
            continue;
        }

        module = ngx_modules[m]->ctx;

        if (module->actions.init(cycle, ngx_timer_resolution) != NGX_OK) {
            /* fatal */
            exit(2);
        }

        break;
    }

#if !(NGX_WIN32)

    if (ngx_timer_resolution && !(ngx_event_flags & NGX_USE_TIMER_EVENT)) {
        struct sigaction  sa;
        struct itimerval  itv;

        ngx_memzero(&sa, sizeof(struct sigaction));
        sa.sa_handler = ngx_timer_signal_handler;
        sigemptyset(&sa.sa_mask);

        if (sigaction(SIGALRM, &sa, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "sigaction(SIGALRM) failed");
            return NGX_ERROR;
        }

        itv.it_interval.tv_sec = ngx_timer_resolution / 1000;
        itv.it_interval.tv_usec = (ngx_timer_resolution % 1000) * 1000;
        itv.it_value.tv_sec = ngx_timer_resolution / 1000;
        itv.it_value.tv_usec = (ngx_timer_resolution % 1000 ) * 1000;

        if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setitimer() failed");
        }
    }

    if (ngx_event_flags & NGX_USE_FD_EVENT) {
        struct rlimit  rlmt;

        if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "getrlimit(RLIMIT_NOFILE) failed");
            return NGX_ERROR;
        }

        cycle->files_n = (ngx_uint_t) rlmt.rlim_cur;

        cycle->files = ngx_calloc(sizeof(ngx_connection_t *) * cycle->files_n,
                                  cycle->log);
        if (cycle->files == NULL) {
            return NGX_ERROR;
        }
    }

#endif

    cycle->connections =
        ngx_alloc(sizeof(ngx_connection_t) * cycle->connection_n, cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    c = cycle->connections;

    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                   cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
        rev[i].instance = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                    cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

    i = cycle->connection_n;
    next = NULL;

    do {
        i--;

        c[i].data = next;
        c[i].read = &cycle->read_events[i];
        c[i].write = &cycle->write_events[i];
        c[i].fd = (ngx_socket_t) -1;

        next = &c[i];

#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    } while (i);

    cycle->free_connections = next;
    cycle->free_connection_n = cycle->connection_n;

    /* for each listening socket */

    ls = cycle->listening.elts;
    for (i = 0; i < cycle->listening.nelts; i++) {

        c = ngx_get_connection(ls[i].fd, cycle->log);

        if (c == NULL) {
            return NGX_ERROR;
        }

        c->log = &ls[i].log;

        c->listening = &ls[i];
        ls[i].connection = c;

        rev = c->read;

        rev->log = c->log;
        rev->accept = 1;

#if (NGX_HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = ls[i].deferred_accept;
#endif

        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (ls[i].previous) {

                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */

                old = ls[i].previous->connection;

                if (ngx_del_event(old->read, NGX_READ_EVENT, NGX_CLOSE_EVENT)
                    == NGX_ERROR)
                {
                    return NGX_ERROR;
                }

                old->fd = (ngx_socket_t) -1;
            }
        }

#if (NGX_WIN32)

        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            ngx_iocp_conf_t  *iocpcf;

            rev->handler = ngx_event_acceptex;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            ls[i].log.handler = ngx_acceptex_log_error;

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&ls[i], iocpcf->post_acceptex)
                == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->handler = ngx_event_accept;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else

        rev->handler = ngx_event_accept;

        if (ngx_use_accept_mutex) {
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#endif

    }

    return NGX_OK;
}
コード例 #3
0
static ngx_int_t
ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *ls;
    ngx_connection_t    *c, *next, *old;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

	/* [analy]  ngx_use_accept_mutex表示是否需要通过对accept加锁来解决惊群问题。
					当nginx worker进程数>1时且配置文件中打开accept_mutex时,这个标志置为1 
	*/
    if (ccf->master && ccf->worker_processes > 1 && ecf->accept_mutex) {
        ngx_use_accept_mutex = 1;
        ngx_accept_mutex_held = 0;
        ngx_accept_mutex_delay = ecf->accept_mutex_delay;

    } else {
        ngx_use_accept_mutex = 0;
    }

#if (NGX_THREADS)
    ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0);
    if (ngx_posted_events_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

	/* [analy]	??????????? */
    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

	/* [analy]	调用事件处理模块(epoll)初始化函数 */
    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        if (ngx_modules[m]->ctx_index != ecf->use) {
            continue;
        }

		/* [analy]
			由于Nginx实现了很多的事件模块,比如:epoll,poll,select, kqueue,aio 
			(这些模块位于src/event/modules目录中)等等,所以Nginx对事件模块进行 
			了一层抽象,方便在不同的系统上使用不同的事件模型,也便于扩展新的事件 
			模型
			此处的init回调,其实就是调用了ngx_epoll_init函数。module->actions结构 
			封装了epoll的所有接口函数。Nginx就是通过actions结构将epoll注册到事件 
			抽象层中。actions的类型是ngx_event_actions_t
		*/
        module = ngx_modules[m]->ctx;

        if (module->actions.init(cycle, ngx_timer_resolution) != NGX_OK) {
            /* fatal */
            exit(2);
        }

        break;
    }

#if !(NGX_WIN32)

	/* 
	 *	timer_resolution指令指定了时间,并且未指定NGX_USE_TIMER_EVENT标记时, 
	 *			根据 timer_resolution 指令指定的时间设置一个定时器
	 */
    if (ngx_timer_resolution && !(ngx_event_flags & NGX_USE_TIMER_EVENT)) {
        struct sigaction  sa;
        struct itimerval  itv;

        ngx_memzero(&sa, sizeof(struct sigaction));
        sa.sa_handler = ngx_timer_signal_handler;
        sigemptyset(&sa.sa_mask);

        if (sigaction(SIGALRM, &sa, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "sigaction(SIGALRM) failed");
            return NGX_ERROR;
        }

        itv.it_interval.tv_sec = ngx_timer_resolution / 1000;
        itv.it_interval.tv_usec = (ngx_timer_resolution % 1000) * 1000;
        itv.it_value.tv_sec = ngx_timer_resolution / 1000;
        itv.it_value.tv_usec = (ngx_timer_resolution % 1000 ) * 1000;

        if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setitimer() failed");
        }
    }

    if (ngx_event_flags & NGX_USE_FD_EVENT) {					/* [analy]	epoll模块不使用 */
        struct rlimit  rlmt;	

        if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "getrlimit(RLIMIT_NOFILE) failed");
            return NGX_ERROR;
        }

        cycle->files_n = (ngx_uint_t) rlmt.rlim_cur;

        cycle->files = ngx_calloc(sizeof(ngx_connection_t *) * cycle->files_n,
                                  cycle->log);
        if (cycle->files == NULL) {
            return NGX_ERROR;
        }
    }

#endif

	/* [analy]	为连接池申请空间,由于此处在worker进程初始化时进行的,所以
					每个worker都会拥有一个自己的connections连接池	
					根据配置worker_connections指令指定的个数申请 */
    cycle->connections =
        ngx_alloc(sizeof(ngx_connection_t) * cycle->connection_n, cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    c = cycle->connections;
	
	/* [analy]	为读事件队列申请空间 */
    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                   cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
        rev[i].instance = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

	/* [analy]	为写事件队列申请空间 */
    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                    cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

	/* [analy]	初始化connections数组
					data字段指向下一个元素
					read事件指针指向read_events对应下标的元素
					write事件指针指向write_events对应下标的元素
					fd初始化-1
	*/

    i = cycle->connection_n;
    next = NULL;

    do {
        i--;

        c[i].data = next;
        c[i].read = &cycle->read_events[i];			/* [analy]	将连接池中connections的read事件与read_events数组中的对应下标的元素关联 */
        c[i].write = &cycle->write_events[i];		/* [analy]	将连接池中connections的write事件与write_events数组中对应下标元素关联 */
        c[i].fd = (ngx_socket_t) -1;

        next = &c[i];

#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    } while (i);

	/* 初始化free_connections空闲连接池和空闲连接个数;指向connections连接池首地址 */
    cycle->free_connections = next;
    cycle->free_connection_n = cycle->connection_n;

	/* [analy]	为每一个套接口分配一个空闲的连接 */
    /* for each listening socket */
    ls = cycle->listening.elts;
    for (i = 0; i < cycle->listening.nelts; i++) {

        c = ngx_get_connection(ls[i].fd, cycle->log);

        if (c == NULL) {
            return NGX_ERROR;
        }

        c->log = &ls[i].log;

        c->listening = &ls[i];					/* [analy]	connection的listening指针指向cycle->listening[n] */	
        ls[i].connection = c;					/* [analy]	cycle->listening[n]->connection指针指向了申请的空闲connection */	
			
        rev = c->read;

        rev->log = c->log;
        rev->accept = 1;						//	设置监听套接字标识

#if (NGX_HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = ls[i].deferred_accept;
#endif

        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (ls[i].previous) {

                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */

                old = ls[i].previous->connection;

                if (ngx_del_event(old->read, NGX_READ_EVENT, NGX_CLOSE_EVENT)
                    == NGX_ERROR)
                {
                    return NGX_ERROR;
                }

                old->fd = (ngx_socket_t) -1;
            }
        }

#if (NGX_WIN32)

        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            ngx_iocp_conf_t  *iocpcf;

            rev->handler = ngx_event_acceptex;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            ls[i].log.handler = ngx_acceptex_log_error;

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&ls[i], iocpcf->post_acceptex)
                == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->handler = ngx_event_accept;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else

        rev->handler = ngx_event_accept;			/* [analy]	设置accpet回调处理函数 */	

        if (ngx_use_accept_mutex) {
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {			/* [analy]	将event送进epoll队列中 */
                return NGX_ERROR;
            }
        }

#endif

    }

    return NGX_OK;
}
コード例 #4
0
// 这篇文章写得很清晰http://www.tbdata.org/archives/1245
static ngx_int_t
ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *ls;
    ngx_connection_t    *c, *next, *old;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;
    // 获取相应模块的配置结构
    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

    // 判断是否使用mutex锁,主要是为了控制负载均衡。ccf->master主要确定下是否是master-worker模式。单进程模式就不需要进行下面操作了。
    if (ccf->master && ccf->worker_processes > 1 && ecf->accept_mutex) {
        //使用mutex控制进程的负载均衡
        ngx_use_accept_mutex = 1;
        ngx_accept_mutex_held = 0;
        ngx_accept_mutex_delay = ecf->accept_mutex_delay; // 抢互斥体失败后,下次再抢的间隔时间

    } else {
        ngx_use_accept_mutex = 0;
    }

#if (NGX_THREADS)
    ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0);
    if (ngx_posted_events_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

    //定时器初始化
    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

    //event module的初始化
    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        if (ngx_modules[m]->ctx_index != ecf->use) {
            continue;
        }

        module = ngx_modules[m]->ctx;
        
        //初始化模块
        if (module->actions.init(cycle, ngx_timer_resolution) != NGX_OK) {
            /* fatal */
            exit(2);
        }

        break;
    }

#if !(NGX_WIN32)

    if (ngx_timer_resolution && !(ngx_event_flags & NGX_USE_TIMER_EVENT)) {
        struct sigaction  sa;
        struct itimerval  itv;

        ngx_memzero(&sa, sizeof(struct sigaction));
        sa.sa_handler = ngx_timer_signal_handler;
        sigemptyset(&sa.sa_mask);

        if (sigaction(SIGALRM, &sa, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "sigaction(SIGALRM) failed");
            return NGX_ERROR;
        }

        itv.it_interval.tv_sec = ngx_timer_resolution / 1000;
        itv.it_interval.tv_usec = (ngx_timer_resolution % 1000) * 1000;
        itv.it_value.tv_sec = ngx_timer_resolution / 1000;
        itv.it_value.tv_usec = (ngx_timer_resolution % 1000 ) * 1000;

        if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setitimer() failed");
        }
    }

    if (ngx_event_flags & NGX_USE_FD_EVENT) {
        struct rlimit  rlmt;

        if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "getrlimit(RLIMIT_NOFILE) failed");
            return NGX_ERROR;
        }

        cycle->files_n = (ngx_uint_t) rlmt.rlim_cur;

        cycle->files = ngx_calloc(sizeof(ngx_connection_t *) * cycle->files_n,
                                  cycle->log);
        if (cycle->files == NULL) {
            return NGX_ERROR;
        }
    }

#endif

    //创建连接池。现在已经是在worker中了,所以每个worker都有自己的connection数组
    cycle->connections =
        ngx_alloc(sizeof(ngx_connection_t) * cycle->connection_n, cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    c = cycle->connections;
    
    //创建所有读事件
    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                   cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    //初始化读事件
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
        //防止stale event
        rev[i].instance = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

    //创建写事件
    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                    cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    //初始化写事件
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

    i = cycle->connection_n;
    next = NULL;

    //初始化连接池
    do {
        i--;
        
        //链表
        c[i].data = next;
        //每一个连接的读写事件对应cycle的读写事件
        c[i].read = &cycle->read_events[i];
        c[i].write = &cycle->write_events[i];
        c[i].fd = (ngx_socket_t) -1;

        next = &c[i];

#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    } while (i);

    //设置free 连接
    cycle->free_connections = next;
    cycle->free_connection_n = cycle->connection_n;

    /* for each listening socket */
    //下面这段初始化listen 事件 ,创建socket句柄,绑定事件回调,然后加入到事件驱动中

    ls = cycle->listening.elts;  // 为每一个监听套接字从connection数组中分配一个连接,即一个slot
    //开始遍历listen
    for (i = 0; i < cycle->listening.nelts; i++) {
        
        //从连接池取得连接
        c = ngx_get_connection(ls[i].fd, cycle->log);

        if (c == NULL) {
            return NGX_ERROR;
        }

        c->log = &ls[i].log;

        c->listening = &ls[i];
        ls[i].connection = c;

        rev = c->read;

        rev->log = c->log;
        rev->accept = 1;

#if (NGX_HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = ls[i].deferred_accept;
#endif

        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (ls[i].previous) {

                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */

                old = ls[i].previous->connection;

                if (ngx_del_event(old->read, NGX_READ_EVENT, NGX_CLOSE_EVENT)
                    == NGX_ERROR)
                {
                    return NGX_ERROR;
                }

                old->fd = (ngx_socket_t) -1;
            }
        }

#if (NGX_WIN32)

        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            ngx_iocp_conf_t  *iocpcf;

            rev->handler = ngx_event_acceptex;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            ls[i].log.handler = ngx_acceptex_log_error;

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&ls[i], iocpcf->post_acceptex)
                == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->handler = ngx_event_accept;  // 注册监听套接读事件的回调函数ngx_event_accept

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else
        
        //设置listen句柄的事件回调,这个回调里面会accept,然后进行后续处理,这个函数是nginx事件驱动的第一个函数
        rev->handler = ngx_event_accept;

        //如果默认使用mutex,则会继续下面操作
        if (ngx_use_accept_mutex) {
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
            //加可读事件到事件处理,如果没有使用accept互斥体,那么就在此处将监听套接字放入
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#endif

    }

    return NGX_OK;
}
コード例 #5
0
static ngx_int_t ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_socket_t         fd;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *s;
    ngx_connection_t    *c;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;
#if (WIN32)
    ngx_iocp_conf_t     *iocpcf;
#endif

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

    // 如果accept时需要锁, 那么初始化锁
    if (ngx_accept_mutex_ptr && ccf->worker_processes > 1 && ecf->accept_mutex)
    {
        ngx_accept_mutex = ngx_accept_mutex_ptr;
        ngx_accept_mutex_held = 0;
        ngx_accept_mutex_delay = ecf->accept_mutex_delay;
    }

#if (NGX_THREADS)
    if (!(ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0))) {
        return NGX_ERROR;
    }
#endif

    // 初始化定时器
    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

    cycle->connection_n = ecf->connections;

    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        // 初始化选定的事件模块
        if (ngx_modules[m]->ctx_index == ecf->use) {
            module = ngx_modules[m]->ctx;
            if (module->actions.init(cycle) == NGX_ERROR) {
                /* fatal */
                exit(2);
            }
            break;
        }
    }

    // 根据连接最大数来创建连接对象池
    cycle->connections = ngx_alloc(sizeof(ngx_connection_t) * ecf->connections,
                                   cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    // 初始化连接池
    c = cycle->connections;
    for (i = 0; i < cycle->connection_n; i++) {
        c[i].fd = (ngx_socket_t) -1;
        c[i].data = NULL;
#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    }

    // 初始化事件相关的对象
    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * ecf->connections,
                                   cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * ecf->connections,
                                    cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

    /* for each listening socket */

    // 用事件对象与监听的socket相关联

    s = cycle->listening.elts;
    for (i = 0; i < cycle->listening.nelts; i++) {

        fd = s[i].fd;

#if (WIN32)
        /*
         * Winsock assignes a socket number divisible by 4
         * so to find a connection we divide a socket number by 4.
         */

        fd /= 4;
#endif

        c = &cycle->connections[fd];
        rev = &cycle->read_events[fd];
        wev = &cycle->write_events[fd];

        ngx_memzero(c, sizeof(ngx_connection_t));
        ngx_memzero(rev, sizeof(ngx_event_t));

        c->fd = s[i].fd;
        c->listening = &s[i];

        c->ctx = s[i].ctx;
        c->servers = s[i].servers;
        c->log = s[i].log;
        c->read = rev;

        /* required by iocp in "c->write->active = 1" */
        c->write = wev;

        /* required by poll */
        wev->index = NGX_INVALID_INDEX;

        rev->log = c->log;
        rev->data = c;
        rev->index = NGX_INVALID_INDEX;

        rev->available = 0;

        rev->accept = 1;

#if (HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = s[i].deferred_accept;
#endif

        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (s[i].remain) {

                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */

                if (ngx_del_event(&cycle->old_cycle->read_events[fd],
                                  NGX_READ_EVENT, NGX_CLOSE_EVENT) == NGX_ERROR)
                {
                    return NGX_ERROR;
                }

                cycle->old_cycle->connections[fd].fd = (ngx_socket_t) -1;
            }
        }

#if (WIN32)

        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            rev->event_handler = &ngx_event_acceptex;

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&s[i], iocpcf->post_acceptex)
                    == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->event_handler = &ngx_event_accept;
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else

        rev->event_handler = &ngx_event_accept; // 读事件的回调函数

        // 如果需要accept锁, 那么延迟添加到事件池中
        if (ngx_accept_mutex) {
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#endif
    }

    return NGX_OK;
}
コード例 #6
0
ファイル: ngx_event.c プロジェクト: melong007/nginx_cache
//Here,This function very important!
static ngx_int_t ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *ls;
    ngx_connection_t    *c, *next, *old;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

    if (ccf->master && ccf->worker_processes > 1 && ecf->accept_mutex) {
        ngx_use_accept_mutex = 1; //Means we used a multi worker!!!!
        ngx_accept_mutex_held = 0;
        ngx_accept_mutex_delay = ecf->accept_mutex_delay;

    } else {
        ngx_use_accept_mutex = 0;
    }

#if (NGX_THREADS)
    ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0);
    if (ngx_posted_events_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        if (ngx_modules[m]->ctx_index != ecf->use) {//Here,find the used event scheme!!!!
            continue;
        }

        module = ngx_modules[m]->ctx;

        if (module->actions.init(cycle, ngx_timer_resolution) != NGX_OK) {//Here,we set the global ngx_event_actions!!!!!
            /* fatal */
            exit(2);
        }
        break;
    }

#if !(NGX_WIN32)

    if (ngx_timer_resolution && !(ngx_event_flags & NGX_USE_TIMER_EVENT)) {
        struct sigaction  sa;
        struct itimerval  itv;

        ngx_memzero(&sa, sizeof(struct sigaction));
        sa.sa_handler = ngx_timer_signal_handler;
        sigemptyset(&sa.sa_mask);

        if (sigaction(SIGALRM, &sa, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "sigaction(SIGALRM) failed");
            return NGX_ERROR;
        }

        itv.it_interval.tv_sec = ngx_timer_resolution / 1000;
        itv.it_interval.tv_usec = (ngx_timer_resolution % 1000) * 1000;
        itv.it_value.tv_sec = ngx_timer_resolution / 1000;
        itv.it_value.tv_usec = (ngx_timer_resolution % 1000 ) * 1000;

        if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setitimer() failed");
        }
    }

    if (ngx_event_flags & NGX_USE_FD_EVENT) {
        struct rlimit  rlmt;

        if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "getrlimit(RLIMIT_NOFILE) failed");
            return NGX_ERROR;
        }

        cycle->files_n = (ngx_uint_t) rlmt.rlim_cur;

        cycle->files = ngx_calloc(sizeof(ngx_connection_t *) * cycle->files_n,
                                  cycle->log);
        if (cycle->files == NULL) {
            return NGX_ERROR;
        }
    }

#endif
	//Here,we alloction the connection pool!!
    cycle->connections = ngx_alloc(sizeof(ngx_connection_t) * cycle->connection_n, cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    c = cycle->connections;
	//Here,alloction the read_events pool
    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
        rev[i].instance = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

	//Here,alloction the write_events pool
    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

    i = cycle->connection_n;
    next = NULL;

	//Here,make a pair!!! on connection,to one rev and one wev!!!
    do {
        i--;

        c[i].data = next;//point to the next free connection!!!!
        c[i].read = &cycle->read_events[i];
        c[i].write = &cycle->write_events[i];
        c[i].fd = (ngx_socket_t) -1;

        next = &c[i];

#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    } while (i);

    cycle->free_connections = next;
    cycle->free_connection_n = cycle->connection_n;

    /* for each listening socket */

    ls = cycle->listening.elts;//
//-------------->very important!!!
//-------------->start to initilize a connection for every listening socket!!!
    for (i = 0; i < cycle->listening.nelts; i++) {

        c = ngx_get_connection(ls[i].fd, cycle->log);//Get a free connection!
        if (c == NULL) {
            return NGX_ERROR;
        }
        c->log = &ls[i].log;

        c->listening = &ls[i];//Means this connection bind to this listen socket!!!
        ls[i].connection = c;
        rev = c->read;

        rev->log = c->log;
        rev->accept = 1;
	//Means mark that this rev use to accept request,It is a special read_event!!!
	//This read_event handler should be call be for release the ngx_accept_mutex

#if (NGX_HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = ls[i].deferred_accept;
#endif
        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (ls[i].previous) {
                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */
                old = ls[i].previous->connection;
                if (ngx_del_event(old->read, NGX_READ_EVENT, NGX_CLOSE_EVENT) == NGX_ERROR)
                {
                    return NGX_ERROR;
                }
                old->fd = (ngx_socket_t) -1;
            }
        }

#if (NGX_WIN32)
        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            ngx_iocp_conf_t  *iocpcf;

            rev->handler = ngx_event_acceptex;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            ls[i].log.handler = ngx_acceptex_log_error;

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&ls[i], iocpcf->post_acceptex)
                == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->handler = ngx_event_accept;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else
		//Here,set the read_handler!!!
        rev->handler = ngx_event_accept;

        if (ngx_use_accept_mutex) {
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#endif

    }

    return NGX_OK;
}
コード例 #7
0
static ngx_int_t
ngx_kqueue_init(ngx_cycle_t *cycle, ngx_msec_t timer)
{
    ngx_kqueue_conf_t  *kcf;
    struct timespec     ts;
#if (NGX_HAVE_TIMER_EVENT)
    struct kevent       kev;
#endif

    kcf = ngx_event_get_conf(cycle->conf_ctx, ngx_kqueue_module);

    if (ngx_kqueue == -1) {
        ngx_kqueue = kqueue();

        if (ngx_kqueue == -1) {
            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                          "kqueue() failed");
            return NGX_ERROR;
        }

#if (NGX_THREADS)

        list_mutex = ngx_mutex_init(cycle->log, 0);
        if (list_mutex == NULL) {
            return NGX_ERROR;
        }

        kevent_mutex = ngx_mutex_init(cycle->log, 0);
        if (kevent_mutex == NULL) {
            return NGX_ERROR;
        }

#endif
    }

    if (max_changes < kcf->changes) {
        if (nchanges) {
            ts.tv_sec = 0;
            ts.tv_nsec = 0;

            if (kevent(ngx_kqueue, change_list, (int) nchanges, NULL, 0, &ts)
                == -1)
            {
                ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                              "kevent() failed");
                return NGX_ERROR;
            }
            nchanges = 0;
        }

        if (change_list0) {
            ngx_free(change_list0);
        }

        change_list0 = ngx_alloc(kcf->changes * sizeof(struct kevent),
                                 cycle->log);
        if (change_list0 == NULL) {
            return NGX_ERROR;
        }

        if (change_list1) {
            ngx_free(change_list1);
        }

        change_list1 = ngx_alloc(kcf->changes * sizeof(struct kevent),
                                 cycle->log);
        if (change_list1 == NULL) {
            return NGX_ERROR;
        }

        change_list = change_list0;
    }

    max_changes = kcf->changes;

    if (nevents < kcf->events) {
        if (event_list) {
            ngx_free(event_list);
        }

        event_list = ngx_alloc(kcf->events * sizeof(struct kevent), cycle->log);
        if (event_list == NULL) {
            return NGX_ERROR;
        }
    }

    ngx_event_flags = NGX_USE_ONESHOT_EVENT
                      |NGX_USE_KQUEUE_EVENT
                      |NGX_USE_VNODE_EVENT;

#if (NGX_HAVE_TIMER_EVENT)

    if (timer) {
        kev.ident = 0;
        kev.filter = EVFILT_TIMER;
        kev.flags = EV_ADD|EV_ENABLE;
        kev.fflags = 0;
        kev.data = timer;
        kev.udata = 0;

        ts.tv_sec = 0;
        ts.tv_nsec = 0;

        if (kevent(ngx_kqueue, &kev, 1, NULL, 0, &ts) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "kevent(EVFILT_TIMER) failed");
            return NGX_ERROR;
        }

        ngx_event_flags |= NGX_USE_TIMER_EVENT;
    }

#endif

#if (NGX_HAVE_CLEAR_EVENT)
    ngx_event_flags |= NGX_USE_CLEAR_EVENT;
#else
    ngx_event_flags |= NGX_USE_LEVEL_EVENT;
#endif

#if (NGX_HAVE_LOWAT_EVENT)
    ngx_event_flags |= NGX_USE_LOWAT_EVENT;
#endif

    nevents = kcf->events;

    ngx_io = ngx_os_io;

    ngx_event_actions = ngx_kqueue_module_ctx.actions;

    return NGX_OK;
}
コード例 #8
0
ファイル: ngx_event.c プロジェクト: sykpour/nginx1.0.15_src
//每一个worker进程开始初始化的函数
static ngx_int_t
ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *ls;
    ngx_connection_t    *c, *next, *old;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;

	//获得相应模块的配置结构
    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

	//accept_mutex为1时才会使用互斥体
    if (ccf->master && ccf->worker_processes > 1 && ecf->accept_mutex) {	//当工作进程数目大于1时,用于开启负载均衡情况下,才设置该变量

        ngx_use_accept_mutex = 1;		//1表示使用互斥体
        ngx_accept_mutex_held = 0;		//表示是否获得互斥体
        ngx_accept_mutex_delay = ecf->accept_mutex_delay;	//抢占失败以后,下次再抢的时间,延迟的时间

    } else {
        ngx_use_accept_mutex = 0;		//表示不使用互斥体
    }

#if (NGX_THREADS)
    ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0);
    if (ngx_posted_events_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

	//初始化定时器,这里将会初始化一个红黑树来管理
    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        if (ngx_modules[m]->ctx_index != ecf->use) {	//不是use配置项指定的事件跳过
            continue;
        }

        module = ngx_modules[m]->ctx;

		//调用具体事件模块的函数,如epoll机制的ngx_epoll_init
        if (module->actions.init(cycle, ngx_timer_resolution) != NGX_OK) {
            /* fatal */
            exit(2);
        }

        break;
    }

#if !(NGX_WIN32)

	//如果设置了timer_resolution配置项,表明要控制时间精度,调用setitimer
    if (ngx_timer_resolution && !(ngx_event_flags & NGX_USE_TIMER_EVENT)) {
        struct sigaction  sa;
        struct itimerval  itv;

        ngx_memzero(&sa, sizeof(struct sigaction));
        sa.sa_handler = ngx_timer_signal_handler;
        sigemptyset(&sa.sa_mask);

        if (sigaction(SIGALRM, &sa, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "sigaction(SIGALRM) failed");
            return NGX_ERROR;
        }

        itv.it_interval.tv_sec = ngx_timer_resolution / 1000;		//秒
        itv.it_interval.tv_usec = (ngx_timer_resolution % 1000) * 1000;	//微妙
        itv.it_value.tv_sec = ngx_timer_resolution / 1000;	//循环周期的数
        itv.it_value.tv_usec = (ngx_timer_resolution % 1000 ) * 1000;	

        if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setitimer() failed");
        }
    }

    if (ngx_event_flags & NGX_USE_FD_EVENT) {
        struct rlimit  rlmt;

        if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "getrlimit(RLIMIT_NOFILE) failed");
            return NGX_ERROR;
        }

        cycle->files_n = (ngx_uint_t) rlmt.rlim_cur;

		//file成员
        cycle->files = ngx_calloc(sizeof(ngx_connection_t *) * cycle->files_n,
                                  cycle->log);
        if (cycle->files == NULL) {
            return NGX_ERROR;
        }
    }

#endif

	//创建一个connections数组,直接通过malloc
    cycle->connections =
        ngx_alloc(sizeof(ngx_connection_t) * cycle->connection_n, cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    c = cycle->connections;

	//创建一个读事件数组
    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                   cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
        rev[i].instance = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

	//创建一个写事件数组
    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * cycle->connection_n,
                                    cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

    i = cycle->connection_n;
    next = NULL;

	//初始化整个connections数组
    do {
        i--;

        c[i].data = next;	//串联起来
        c[i].read = &cycle->read_events[i];
        c[i].write = &cycle->write_events[i];
        c[i].fd = (ngx_socket_t) -1;

        next = &c[i];

#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    } while (i);

    cycle->free_connections = next;	//指向一个可用的slot
    cycle->free_connection_n = cycle->connection_n;

    /* for each listening socket */

	//为每一个监听套接字分配一个connection
    ls = cycle->listening.elts;
    for (i = 0; i < cycle->listening.nelts; i++) {

        c = ngx_get_connection(ls[i].fd, cycle->log);		//获得一个可用的connection	
		//对于每一个监听套接口创建对应的connection连接对象

        if (c == NULL) {
            return NGX_ERROR;
        }

        c->log = &ls[i].log;

        c->listening = &ls[i];
        ls[i].connection = c;

        rev = c->read;

        rev->log = c->log;
        rev->accept = 1;	//读事件发生

#if (NGX_HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = ls[i].deferred_accept;
#endif

        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (ls[i].previous) {

                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */

                old = ls[i].previous->connection;

                if (ngx_del_event(old->read, NGX_READ_EVENT, NGX_CLOSE_EVENT)
                    == NGX_ERROR)
                {
                    return NGX_ERROR;
                }

                old->fd = (ngx_socket_t) -1;
            }
        }

#if (NGX_WIN32)

        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            ngx_iocp_conf_t  *iocpcf;

            rev->handler = ngx_event_acceptex;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            ls[i].log.handler = ngx_acceptex_log_error;

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&ls[i], iocpcf->post_acceptex)
                == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->handler = ngx_event_accept;

            if (ngx_use_accept_mutex) {
                continue;
            }

            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else
		//ngx_process_events_and_timers

        rev->handler = ngx_event_accept;	//监听套接字的读事件回调

        if (ngx_use_accept_mutex) {	//设置了该参数,也就跳过了后面的将监听套接口添加到事件监控事件里,避免惊群
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
			//没有使用accept_mutex时,就将监听套接字放入到epoll中
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#endif

    }

    return NGX_OK;
}