nginx0.1.0之http模块初始化源码分析（4）

// 恢复上下文
    *cf = pcf;

    /* init lists of the handlers */

    ngx_init_array(cmcf->phases[NGX_HTTP_REWRITE_PHASE].handlers,
                   cf->cycle->pool, 10, sizeof(ngx_http_handler_pt),
                   NGX_CONF_ERROR);
    cmcf->phases[NGX_HTTP_REWRITE_PHASE].type = NGX_OK;


    /* the special find config phase for single handler */

    ngx_init_array(cmcf->phases[NGX_HTTP_FIND_CONFIG_PHASE].handlers,
                   cf->cycle->pool, 1, sizeof(ngx_http_handler_pt),
                   NGX_CONF_ERROR);
    cmcf->phases[NGX_HTTP_FIND_CONFIG_PHASE].type = NGX_OK;

    ngx_test_null(h, ngx_push_array(
                           &cmcf->phases[NGX_HTTP_FIND_CONFIG_PHASE].handlers),
                  NGX_CONF_ERROR);
    *h = ngx_http_find_location_config;


    ngx_init_array(cmcf->phases[NGX_HTTP_ACCESS_PHASE].handlers,
                   cf->cycle->pool, 10, sizeof(ngx_http_handler_pt),
                   NGX_CONF_ERROR);
    cmcf->phases[NGX_HTTP_ACCESS_PHASE].type = NGX_DECLINED;


    ngx_init_array(cmcf->phases[NGX_HTTP_CONTENT_PHASE].handlers,
                   cf->cycle->pool, 10, sizeof(ngx_http_handler_pt),
                   NGX_CONF_ERROR);
    cmcf->phases[NGX_HTTP_CONTENT_PHASE].type = NGX_OK;


    /*
     * create the lists of the ports, the addresses and the server names
     * to allow quickly find the server core module configuration at run-time
     */

    ngx_init_array(in_ports, cf->pool, 10, sizeof(ngx_http_in_port_t),
                   NGX_CONF_ERROR);

    /* "server" directives */
    cscfp = cmcf->servers.elts;
    // 遍历每个server下的每个listen结构的每个端口，构造端口->地址->servername的多级结构
    for (s = 0; s < cmcf->servers.nelts; s++) {

        /* "listen" directives */
        // 在解析listen指令的时候写入
        lscf = cscfp[s]->listen.elts;
        for (l = 0; l < cscfp[s]->listen.nelts; l++) {

            port_found = 0;

            /* AF_INET only */

            in_port = in_ports.elts;
            for (p = 0; p < in_ports.nelts; p++) {

                if (lscf[l].port == in_port[p].port) {
                    // 端口已经在监听
                    /* the port is already in the port list */

                    port_found = 1;
                    addr_found = 0;
                    // 监听了这个端口的地址列表
                    in_addr = in_port[p].addrs.elts;
                    for (a = 0; a < in_port[p].addrs.nelts; a++) {
                        // 监听的端口相等，判断地址是否也相等
                        if (lscf[l].addr == in_addr[a].addr) {

                            /* the address is already bound to this port */

                            /* "server_name" directives */
                            // server对应的servername列表
                            s_name = cscfp[s]->server_names.elts;
                            for (n = 0; n < cscfp[s]->server_names.nelts; n++) {

                                /*
                                 * add the server name and server core module
                                 * configuration to the address:port
                                 */

                                /* TODO: duplicate names can be checked here */

                                ngx_test_null(name,
                                              ngx_push_array(&in_addr[a].names),
                                              NGX_CONF_ERROR);

                                name->name = s_name[n].name;
                                name->core_srv_conf = s_name[n].core_srv_conf;
                            }

                            /*
                             * check duplicate "default" server that
                             * serves this address:port
                             */
                            // 同一个server配置里只能有一个default_server
                            if (lscf[l].default_server) {
                                if (in_addr[a].default_server) {
                                    ngx_log_error(NGX_LOG_ERR, cf->log, 0,
                                           "duplicate default server in %s:%d",
                                           lscf[l].file_name.data,
                                           lscf[l].line);

                                    return NGX_CONF_ERROR;
                                }

                                in_addr[a].core_srv_conf = cscfp[s];
                                in_addr[a].default_server = 1;
                            }

                            addr_found = 1;

                            break;

                        } else if (in_addr[a].addr == INADDR_ANY) {

                            /*
                             * "*:port" must be the last resort so move it
                             * to the end of the address list and add
                             * the new address at its place
                             */
                            /*
                                如果监听的地址是any，则把any的项放到地址列表的最后，
                                原来的位置填充当前的listen配置的信息,遍历到any项说明
                                已经是地址列表的最后一项
                            */
                            ngx_test_null(inaddr,
                                          ngx_push_array(&in_port[p].addrs),
                                          NGX_CONF_ERROR);

                            ngx_memcpy(inaddr, &in_addr[a],
                                       sizeof(ngx_http_in_addr_t));

                            in_addr[a].addr = lscf[l].addr;
                            in_addr[a].default_server = lscf[l].default_server;
                            in_addr[a].core_srv_conf = cscfp[s];

                            /*
                             * create the empty list of the server names that
                             * can be served on this address:port
                             */

                            ngx_init_array(inaddr->names, cf->pool, 10,
                                           sizeof(ngx_http_server_name_t),
                                           NGX_CONF_ERROR);
                            // 置1，下面不需要再新增一个项
                            addr_found = 1;
                            // 跳出循环，因为已经遍历到了any项了，说明是最后一项了
                            break;
                        }
                    }
                    // 还没有该地址的项，新增一个
                    if (!addr_found) {

                        /*
                         * add the address to the addresses list that
                         * bound to this port
                         */

                        ngx_test_null(inaddr,
                                      ngx_push_array(&in_port[p].addrs),
                                      NGX_CONF_ERROR);

                        inaddr->addr = lscf[l].addr;
                        inaddr->default_server = lscf[l].default_server;
                        inaddr->core_srv_conf = cscfp[s];

                        /*
                         * create the empty list of the server names that
                         * can be served on this address:port
                         */

                        ngx_init_array(inaddr->names, cf->pool, 10,
                                       sizeof(ngx_http_server_name_t),
                                       NGX_CONF_ERROR);
                    }
                }
            }
            // 在已监听端口里没有找到当前端口
            if (!port_found) {

                /* add the port to the in_port list */
                // 记录该端口
                ngx_test_null(in_port,
                              ngx_push_array(&in_ports),
                              NGX_CONF_ERROR);

                in_port->port = lscf[l].port;

                ngx_test_null(in_port->port_text.data, ngx_palloc(cf->pool, 7),
                              NGX_CONF_ERROR);
                in_port->port_text.len = ngx_snprintf((char *)
                                                      in_port->port_text.data,
                                                      7, ":%d",
                                                      in_port->port);

                /* create list of the addresses that bound to this port ... */
                // 监听了这个端口的地址列表
                ngx_init_array(in_port->addrs, cf->pool, 10,
                               sizeof(ngx_http_in_addr_t),
                               NGX_CONF_ERROR);

                ngx_test_null(inaddr, ngx_push_array(&in_port->addrs),
                              NGX_CONF_ERROR);

                /* ... and add the address to this list */

                inaddr->addr = lscf[l].addr;
                inaddr->default_server = lscf[l].default_server;
                // 记录server配置，方便后续快速查找
                inaddr->core_srv_conf = cscfp[s];

                /*
                 * create the empty list of the server names that
                 * can be served on this address:port
                 */

                ngx_init_array(inaddr->names, cf->pool, 10,
                               sizeof(ngx_http_server_name_t),
                               NGX_CONF_ERROR);
            }
        }
    }
    // 代码执行到这，内存视图对应下图的图一（圆圈里是1）。
    /* optimize the lists of the ports, the addresses and the server names */

    /* AF_INET only */
    // 优化，如果不存在虚拟主机则不需要保存servername，因为servername是用来匹配虚拟主机的
    // 监听的端口列表
    in_port = in_ports.elts;
    for (p = 0; p < in_ports.nelts; p++) {

        /* check whether the all server names point to the same server */
        // 地址列表
        in_addr = in_port[p].addrs.elts;
        for (a = 0; a < in_port[p].addrs.nelts; a++) {

            virtual_names = 0;
            // servername列表
            name = in_addr[a].names.elts;
            for (n = 0; n < in_addr[a].names.nelts; n++) {
                /*
                    比较当前的地址和该地址下所有的servername，如果指向的server配置
                    是一样的，说明当前的地址收到连接或者请求的时候，直接给server里配置的服务
                    就行，如果有一个servername指向的server配置和当前地址的不一样，说明当一个请求或
                    连接到来时，nginx无法通过地址决定该请求转发给哪个服务，还需要servername信息，即
                    虚拟主机名
                */
                if (in_addr[a].core_srv_conf != name[n].core_srv_conf) {
                    virtual_names = 1;
                    break;
                }
            }

            /*
             * if the all server names point to the same server
             * then we do not need to check them at run-time
             */
            // 没有配置虚拟主机则不需要保存servername信息
            if (!virtual_names) {
                in_addr[a].names.nelts = 0;
            }
        }

        /*
         * if there's the binding to "*:port" then we need to bind()
         * to "*:port" only and ignore the other bindings
         */
        // 地址列表的最后一项是不是any，如果绑定的地址中有any，则绑定该地址即可，其他的地址不需要绑定了
        if (in_addr[a - 1].addr == INADDR_ANY) {
            a--;

        } else {
            a = 0;
        }

        in_addr = in_port[p].addrs.elts;
        while (a < in_port[p].addrs.nelts) {
            // push到cycle->listening中，并填充某些字段
            ls = ngx_listening_inet_stream_socket(cf, in_addr[a].addr,
                                                  in_port[p].port);
            if (ls == NULL) {
                return NGX_CONF_ERROR;
            }

            ls->backlog = -1;
#if 0
#if 0
            ls->nonblocking = 1;
#else
            ls->nonblocking = 0;
#endif
#endif
            ls->addr_ntop = 1;

            ls->handler = ngx_http_init_connection;
            // 地址对应的server配置
            cscf = in_addr[a].core_srv_conf;
            ls->pool_size = cscf->connection_pool_size;
            ls->post_accept_timeout = cscf->post_accept_timeout;

            clcf = cscf->ctx->loc_conf[ngx_http_core_module.ctx_index];
            ls->log = clcf->err_log;

#if (WIN32)
            iocpcf = ngx_event_get_conf(cf->cycle->conf_ctx, ngx_iocp_module);
            if (iocpcf->acceptex_read) {
                ls->post_accept_buffer_size = cscf->client_header_buffer_size;
            }
#endif

            ls->ctx = ctx;
            // 有多个地址并且没有监听any地址
            if (in_port[p].addrs.nelts > 1) {

                in_addr = in_port[p].addrs.elts;
                // 没有绑定any的配置
                if (in_addr[in_port[p].addrs.nelts - 1].addr != INADDR_ANY) {

                    /*
                     * if this port has not the "*:port" binding then create
                     * the separate ngx_http_in_port_t for the all bindings
                     */
                    /*
                        分配一个新的端口和地址结构，形成一个端口对应一个地址的结构，
                        但是servername是共享的，比如端口1*地址数+端口2*地址数个结构体
                    */
                    ngx_test_null(inport,
                                  ngx_palloc(cf->pool,
                                             sizeof(ngx_http_in_port_t)),
                                  NGX_CONF_ERROR);
                    // 复制
                    inport->port = in_port[p].port;
                    inport->port_text = in_port[p].port_text;

                    /* init list of the addresses ... */

                    ngx_init_array(inport->addrs, cf->pool, 1,
                                   sizeof(ngx_http_in_addr_t),
                                   NGX_CONF_ERROR);

                    /* ... and set up it with the first address */
                    // 地址等于当前循环的地址
                    inport->addrs.nelts = 1;
                    inport->addrs.elts = in_port[p].addrs.elts;

                    ls->servers = inport;

                    /* prepare for the next cycle */
                    // 指向地址列表中下一个地址
                    in_port[p].addrs.elts = (char *) in_port[p].addrs.elts
                                                       + in_port[p].addrs.size;
                    in_port[p].addrs.nelts--;

                    in_addr = (ngx_http_in_addr_t *) in_port[p].addrs.elts;
                    a = 0;

                    continue;
                }
            }

            ls->servers = &in_port[p];
            a++;
        }
    }

// 初始化listening结构体中ip地址和端口相关的字段
ngx_listening_t *ngx_listening_inet_stream_socket(ngx_conf_t *cf,
                                                 in_addr_t addr,
                                                 in_port_t port)
{
    size_t               len;
    ngx_listening_t     *ls;
    struct sockaddr_in  *addr_in;

    if (!(ls = ngx_array_push(&cf->cycle->listening))) {
        return NULL;
    }

    ngx_memzero(ls, sizeof(ngx_listening_t));

    if (!(addr_in = ngx_pcalloc(cf->pool, sizeof(struct sockaddr_in)))) {
        return NULL;
    }

#if (HAVE_SIN_LEN)
    addr_in->sin_len = sizeof(struct sockaddr_in);
#endif
    addr_in->sin_family = AF_INET;
    addr_in->sin_addr.s_addr = addr;
    addr_in->sin_port = htons(port);

    if (!(ls->addr_text.data = ngx_palloc(cf->pool, INET_ADDRSTRLEN + 6))) {
        return NULL;
    }

    len = ngx_inet_ntop(AF_INET, &addr, ls->addr_text.data, INET_ADDRSTRLEN);
    ls->addr_text.len = ngx_snprintf((char *) ls->addr_text.data + len,
                                     6, ":%d", port);

    ls->fd = (ngx_socket_t) -1;
    ls->family = AF_INET;
    ls->type = SOCK_STREAM;
    ls->protocol = IPPROTO_IP;
#if (WIN32)
    ls->flags = WSA_FLAG_OVERLAPPED;
#endif
    ls->sockaddr = (struct sockaddr *) addr_in;
    ls->socklen = sizeof(struct sockaddr_in);
    ls->addr = offsetof(struct sockaddr_in, sin_addr);
    ls->addr_text_max_len = INET_ADDRSTRLEN;

    return ls;
}