x集成测试状态迁移

来源：互联网发布：ps cs6去掉元数据编辑：程序博客网时间：2024/05/23 22:48

昨天改完后集成测试一下，不经意直接程序出现异常，apt一下

tcp 0 0 *:7777 *:* LISTEN 32686/PC_***
tcp 0 0 linux:7777 linux:38318 ESTABLISHED 32686/PC_***
tcp 0 0 linux:34833 linux:7777 CLOSE_WAIT 28132/java
tcp 0 0 linux:58603 linux:7777 CLOSE_WAIT 28132/java
tcp 0 0 linux:38318 linux:7777 ESTABLISHED 28132/java
tcp 0 0 linux:49424 linux:7777 CLOSE_WAIT 28132/java

晕怎么这么多CLOSE_WAIT ，再复习一下tcp的状态迁移

有了这个信息再看代码很快定位到异常。

顺便再把网络事件类总结一下，以免以后做别的项目了这块出问题得看半天，在X项目中把libevent的网络事件进行了二次封装;

a.两条队列一个记录设控读写事件一个记录active事件；一个树，记录设控时间
b.状态ev_flags ，与4个标志

以time为例

1.添加

event_queue_insert(base, ev, EVLIST_TIMEOUT);{        ......    ev->ev_flags |= queue;    ......    case EVLIST_TIMEOUT:        {            wt_rbtree_insert(&base->timetree, &ev->ev_timeout_node);            break;        }        .......}

2.loop

    ......    if (!base->event_count_active && !(flags & EVLOOP_NONBLOCK))          timeout_next(base, &tv);    else          timerclear(&tv);     /* If we have no events, we just exit */     if (!event_haveevents(base))          return (1);     res = epoll_dispatch(base, evbase, &tv);     if (res == -1)            return (-1);     timeout_process(base);     ......               void     timeout_process(struct event_base *base)      {        ......                     遍历红黑树     event_queue_remove(base, ev, EVLIST_TIMEOUT);     /*    {        case EVLIST_TIMEOUT:            wt_rbtree_delete(&base->timetree, &ev->ev_timeout_node);            break;        }    */    event_active(ev, EV_TIMEOUT, 1);            ......       }               在又见到了我们熟悉的     event_queue_insert(ev->ev_base, ev, EVLIST_ACTIVE);

3.proc

 static void    event_process_active(struct event_base *base)    {          遍历          if (ev->ev_events & EV_PERSIST)                  event_queue_remove(base, ev, EVLIST_ACTIVE);  else  event_del(ev);  回调 ncalls    }

Faq

1.libevent重要结构与函数赏析

不管 什么场景只要处理 read write事件就行了(带外数据可以不考虑)重要结构a.事件struct event {          ....      int ev_flags;   };事件状态 #define EVLIST_INIT0x80#define EVLIST_INSERTED0x02#define EVLIST_ACTIVE0x08#define EVLIST_TIMEOUT0x01b.epoll框架struct event_base {    ngx_queue_t    activequeue;    ngx_queue_t    eventqueue;     ngx_rbtree_t   timetree;};c. epoll 中struct evepoll {struct event *evread;struct event *evwrite;};struct epollop {struct evepoll *fds;  //why hasint nfds;struct epoll_event *events;int nevents;int epfd;sigset_t evsigmask;} epollop;函数a. event_init    ngx_queue_init(¤t_base->eventqueue);    ngx_queue_init(¤t_base->activequeue);    ngx_rbtree_init(¤t_base->timetree, ¤t_base->sentinel, ngx_rbtree_insert_value);    重要初始化三个结构    b. event_set      ev->ev_flags = EVLIST_INIT;    c. event_add      //对于读写事件    if ((ev->ev_events & (EV_READ | EV_WRITE)) &&            !(ev->ev_flags & (EVLIST_INSERTED | EVLIST_ACTIVE)))     {         event_queue_insert(base, ev, EVLIST_INSERTED);        return (epoll_add(evbase, ev));    }    epoll_add             if (evep->evread != NULL)     {        events |= EPOLLIN;        op = EPOLL_CTL_MOD;    }    if (evep->evwrite != NULL)    {        events |= EPOLLOUT;        op = EPOLL_CTL_MOD;    }        if (ev->ev_events & EV_READ)           events |= EPOLLIN;    if (ev->ev_events & EV_WRITE)        events |= EPOLLOUT;            if (ev->ev_events & EV_READ)        evep->evread = ev;    if (ev->ev_events & EV_WRITE)        evep->evwrite = ev;                d.   event_base_loop          res = epoll_dispatch(base, evbase, &tv);     if (res == -1)          return (-1);     timeout_process(base);     if (base->event_count_active)      {          event_process_active(base); //处理激活队列中的          if (!base->event_count_active && (flags & EVLOOP_ONCE))                done = 1;     }           epoll_dispatch          if (evread != NULL && !(evread->ev_events & EV_PERSIST))          event_del(evread);     if (evwrite != NULL && evwrite != evread &&                !(evwrite->ev_events & EV_PERSIST))          event_del(evwrite);     if (evread != NULL)          event_active(evread, EV_READ, 1);     if (evwrite != NULL)          event_active(evwrite, EV_WRITE, 1);                     //处理完就删除，这个与一般的epoll不同所以要加  EV_PERSIST                        event_queue_remove           队列相关    ev->ev_flags &= ~queue;        event_queue_insert    ev->ev_flags |= queue;

2. nginx 平滑重启 nginx -s reload

3. 以一种非优雅的方式断开连接的时候，我们可以设置SO_KEEPALIVE属性使得我们在2小时以后发现对方的TCP连接是否依然存在。
keepAlive = 1;
Setsockopt(listenfd, SOL_SOCKET, SO_KEEPALIVE, (void*)&keepAlive, sizeof(keepAlive))

4. 代码复杂度与sourcemonitor

参考:

1. epoll 事件类型 http://blog.csdn.net/huangjm_13/article/details/17676591
2.state与api http://blog.163.com/xychenbaihu@yeah/blog/static/13222965520118139252103/
3.closewait http://blog.chinaunix.net/uid-20357359-id-1963662.html

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