套接字连接状态检测

sofu456

发布于 2021-12-06 14:30:22

9460

发布于 2021-12-06 14:30:22

文章被收录于专栏：sofu456

主动断开连接

主动断开连接会发送，关闭事件

connec函数检测连接状态，getlasterror
send发送（tcp keeplive心跳包或者有数据时检测），recv接收判断异常（无数据判断异常）
linux中的

select（socket用户和内核传递数组，大小有限制）
poll（同select大小无限制，链表维护）
epoll（内核态数据）

拔网线

拔网线后，关闭事件不能传递，连接状态不好检测

设置连接或者发送超时，同步套接字超时设置

// platform-specific switch
#if defined _WIN32 || defined WIN32 || defined OS_WIN64 || defined _WIN64 || defined WIN64 || defined WINNT
  // use windows-specific time
  int32_t timeout = timeout_milli;
  setsockopt(tcpsocket->native_handle(), SOL_SOCKET, SO_RCVTIMEO, (const char*)&timeout, sizeof(timeout));
  setsockopt(tcpsocket->native_handle(), SOL_SOCKET, SO_SNDTIMEO, (const char*)&timeout, sizeof(timeout));
#else
  // assume everything else is posix
  struct timeval tv;
  tv.tv_sec  = timeout_milli / 1000;
  tv.tv_usec = (timeout_milli % 1000) * 1000;
  setsockopt(tcpsocket->native_handle(), SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
  setsockopt(tcpsocket->native_handle(), SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
#endif

设置keep_alive，linux和windows的结构不同

linux

int keepalive = 1; // 开启keepalive属性
int keepidle = 60; // 如该连接在60秒内没有任何数据往来,则进行探测
int keepinterval = 5; // 探测时发包的时间间隔为5 秒
int keepcount = 3; // 探测尝试的次数.如果第1次探测包就收到响应了,则后2次的不再发.
setsockopt(rs, SOL_SOCKET, SO_KEEPALIVE, (void *)&keepalive , sizeof(keepalive ));
setsockopt(rs, SOL_TCP, TCP_KEEPIDLE, (void*)&keepidle , sizeof(keepidle ));
setsockopt(rs, SOL_TCP, TCP_KEEPINTVL, (void *)&keepinterval , sizeof(keepinterval ));
setsockopt(rs, SOL_TCP, TCP_KEEPCNT, (void *)&keepcount , sizeof(keepcount ));

windows

#include <mstcpip.h>
in_keep_alive.onoff = 1;                    /*打开keepalive*/  
in_keep_alive.keepaliveinterval = 5000; /*发送keepalive心跳时间间隔-单位为毫秒*/  
in_keep_alive.keepalivetime = 10000;         /*多长时间没有报文开始发送keepalive心跳包-单位为毫秒*/  
ret = WSAIoctl(socket, SIO_KEEPALIVE_VALS, (LPVOID)&in_keep_alive, ul_in_len,   
    (LPVOID)&out_keep_alive, ul_out_len, &ul_bytes_return, NULL, NULL);

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原始发表：2021/11/25 ，如有侵权请联系 cloudcommunity@tencent.com 删除

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