windows下
此处的”非正常断开”指TCP连接不是以优雅的方式断开,如网线故障等物理链路的原因,还有突然主机断电等原因
有两种方法可以检测:1.TCP连接双方定时发握手消息
2.利用TCP协议栈中的KeepAlive探测
第二种方法简单可靠,只需对TCP连接两个Socket设定KeepAlive探测,
所以本文只讲第二种方法在Linux,Window2000下的实现(在其它的平台上没有作进一步的测试)
Windows
2000平台下
头文件
#include
<mstcpip.h>
//定义结构及宏
struct
TCP_KEEPALIVE {
u_longonoff;
u_longkeepalivetime;
u_longkeepaliveinterval;
}
;
1. tcp_keepalive live,liveout;
2. live.keepaliveinterval=500;
3. live.keepalivetime=3000;
4. live.onoff=TRUE;
5. int iRet = setsockopt(Socket,SOL_SOCKET,SO_KEEPALIVE,(char
*)Opt,sizeof(int));
6. if(iRet == 0){
7.
8. DWORD dw;
9.
10.
if(WSAIoctl(Socket,SIO_KEEPALIVE_VALS,&live,sizeof(live),&liveout,sizeof(liveout),&dw,NULL,NULL)==
SOCKET_ERROR){
11.
12.
//Delete Client
13.
14.
return;
15.
}
16.
}
ACE下代码
//by rainfish blog.csdn.net/bat603
int Opt = 1;
//在测试过程中，发现检测的次数是5次，即下面的设置中，从最近一次消息开始计算的10秒后，每次间隔5秒，连续发送5次，即
//35秒发现网络断了
tcp_keepalive
live,liveout;
live.keepaliveinterval=5000;
//每次检测的间隔 （单位毫秒）
live.keepalivetime=10000;
//第一次开始发送的时间（单位毫秒）
live.onoff=TRUE;
int
iRet = stream.set_option(SOL_SOCKET,SO_KEEPALIVE,&Opt,sizeof(int));
if(iRet
== 0){
DWORD dw;
//此处显示了在ACE下获取套接字的方法，即句柄的(SOCKET)化就是句柄
if(WSAIoctl((SOCKET)h,SIO_KEEPALIVE_VALS,&live,sizeof(live),&liveout,sizeof(liveout),&dw,NULL,NULL)==
SOCKET_ERROR){
//Delete Client
return;
}
}
Linux平台下
#include
"/usr/include/linux/tcp.h"
#include
"/usr/include/linux/socket.h"
////KeepAlive实现，单位秒
//下面代码要求有ACE,如果没有包含ACE,则请把用到的ACE函数改成linux相应的接口
int
keepAlive = 1;//设定KeepAlive
int
keepIdle = 5;//开始首次KeepAlive探测前的TCP空闭时间
int
keepInterval = 5;//两次KeepAlive探测间的时间间隔
int
keepCount = 3;//判定断开前的KeepAlive探测次数
if(setsockopt(s,SOL_SOCKET,SO_KEEPALIVE,(void*)&keepAlive,sizeof(keepAlive))
== -1)
{
ACE_DEBUG
((LM_INFO,
ACE_TEXT
("(%P|%t) setsockopt SO_KEEPALIVE error!/n")));
}
if(setsockopt(s,SOL_TCP,TCP_KEEPIDLE,(void
*)&keepIdle,sizeof(keepIdle)) == -1)
{
ACE_DEBUG
((LM_INFO,
ACE_TEXT
("(%P|%t) setsockopt TCP_KEEPIDLE error!/n")));
}
if(setsockopt(s,SOL_TCP,TCP_KEEPINTVL,(void
*)&keepInterval,sizeof(keepInterval)) == -1)
{
ACE_DEBUG
((LM_INFO,
ACE_TEXT
("(%P|%t) setsockopt TCP_KEEPINTVL error!/n")));
}
if(setsockopt(s,SOL_TCP,TCP_KEEPCNT,(void
*)&keepCount,sizeof(keepCount)) == -1)
{
ACE_DEBUG
((LM_INFO,
ACE_TEXT
("(%P|%t)setsockopt TCP_KEEPCNT error!/n")));
}
对方网络非正常断开检测方法
原文：http://www.cnblogs.com/lidabo/p/3553128.html
