转：SOCKET编程进阶之Overlapped I\O完成例程模型
SOCKET编程进阶之Overlapped I\O完成例程模型
原文地址:http://blog.csdn.net/echoff/archive/2007/09/23/1797319.aspx
完成例程模型相比与事件通知模型有个很大的优点就是不再受64个消息的限制，一个线程可以同时管理成百上千个socket连接，且保持较高的性能。
完成例程相比与完成端口较为逊色，因为它的性能不能随着系统CPU数量的增长而线程增长，不过在我看来已经很强了，呵呵～！
说白了，这些连接都是由系统来帮你管理的。你只需做的一件事就是：开启一个线程来accept进来的连接，剩下的工作交由系统来处理。而你，则需要提供给系统一个回调函数，发生新的网络事件的时候系统将执行这个函数：
procedure WorkerRoutine( const dwError, cbTransferred : DWORD; const lpOverlapped : LPWSAOVERLAPPED; const dwFlags : DWORD ); stdcall;
然后告诉系统用WorkerRoutine函数处理接收到的数据：
WSARecv( m_socket, @FBuf, 1, dwTemp, dwFlag, @m_overlap, WorkerRoutine );
然后......没有什么然后了，系统什么都给你做了！
代码
#pragma
comment(lib,"ws2_32.lib")
#include
<
winsock2.h
>
#include
<
stdio.h
>
#define
DATA_BUFSIZE 1024
//
接收缓冲区大小
#define
MAXSESSION 10000
//
最大连接数
typedef
struct
_SOCKET_INFORMATION {
OVERLAPPED Overlapped;
SOCKET Socket;
WSABUF DataBuf;
DWORD BytesSEND;
DWORD BytesRECV;
} SOCKET_INFORMATION,
*
LPSOCKET_INFORMATION;
SOCKET ListenSocket
=
INVALID_SOCKET;
DWORD Flags
=
0
;
//
WSARecv的参数
void
CALLBACK WorkerRoutine(DWORD Error, DWORD BytesTransferred,LPWSAOVERLAPPED Overlapped, DWORD InFlags);
DWORD WINAPI AcceptThread(LPVOID lpParameter)
{
WSADATA wsaData;
WSAStartup(MAKEWORD(
2
,
2
),
&
wsaData);
ListenSocket
=
WSASocket(AF_INET,SOCK_STREAM,IPPROTO_TCP,NULL,NULL,WSA_FLAG_OVERLAPPED);
SOCKADDR_IN ServerAddr;
ServerAddr.sin_family
=
AF_INET;
ServerAddr.sin_addr.S_un.S_addr
=
htonl(INADDR_ANY);
ServerAddr.sin_port
=
htons(
1234
);
bind(ListenSocket,(LPSOCKADDR)
&
ServerAddr,
sizeof
(ServerAddr));
listen(ListenSocket,
100
);
printf(
"
listenning...\n
"
);
SOCKADDR_IN ClientAddr;
int
addr_length
=
sizeof
(ClientAddr);
while
(TRUE)
{
LPSOCKET_INFORMATION SI
=
new
SOCKET_INFORMATION;
if
((SI
->
Socket
=
accept(ListenSocket,(SOCKADDR
*
)
&
ClientAddr,
&
addr_length))
!=
INVALID_SOCKET)
{
printf(
"
accept ip:%s port:%d\n
"
,inet_ntoa(ClientAddr.sin_addr),ClientAddr.sin_port);
memset(
&
SI
->
Overlapped,
0
,
sizeof
(WSAOVERLAPPED));
SI
->
DataBuf.buf
=
new
char
[DATA_BUFSIZE];
SI
->
DataBuf.len
=
DATA_BUFSIZE;
memset(SI
->
DataBuf.buf,
0
,DATA_BUFSIZE);
if
(WSARecv(SI
->
Socket,
&
SI
->
DataBuf,
1
,
&
SI
->
BytesRECV,
&
Flags,
&
SI
->
Overlapped, WorkerRoutine)
==
SOCKET_ERROR)
{
int
err
=
WSAGetLastError();
if
(WSAGetLastError()
!=
WSA_IO_PENDING)
{
printf(
"
disconnect\n
"
);
closesocket(SI
->
Socket);
delete [] SI
->
DataBuf.buf;
delete SI;
continue
;
}
}
}
}
return
FALSE;
}
void
CALLBACK WorkerRoutine(DWORD Error, DWORD BytesTransferred, LPWSAOVERLAPPED Overlapped, DWORD InFlags)
{
LPSOCKET_INFORMATION SI
=
(LPSOCKET_INFORMATION)Overlapped;
if
(Error
!=
0
||
BytesTransferred
==
0
)
{
printf(
"
disconnect\n
"
);
closesocket(SI
->
Socket);
delete [] SI
->
DataBuf.buf;
delete SI;
return
;
}
//
使用数据
printf(
"
call back:%s\n
"
,SI
->
DataBuf.buf);
memset(SI
->
DataBuf.buf,
0
,DATA_BUFSIZE);
if
(WSARecv(SI
->
Socket,
&
SI
->
DataBuf,
1
,
&
SI
->
BytesRECV,
&
Flags,
&
SI
->
Overlapped, WorkerRoutine)
==
SOCKET_ERROR)
{
int
err
=
WSAGetLastError();
if
(WSAGetLastError()
!=
WSA_IO_PENDING)
{
printf(
"
disconnect\n
"
);
closesocket(SI
->
Socket);
delete [] SI
->
DataBuf.buf;
delete SI;
return
;
}
}
}
void
main()
{
HANDLE hThreads
=
CreateThread(NULL,
0
, AcceptThread, NULL, NULL, NULL);
WaitForSingleObject(hThreads,INFINITE);
printf(
"
exit\n
"
);
CloseHandle(hThreads);
}
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//
blog.csdn.net/andylin02/archive/2008/10/12/3062724.aspx
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/andylin02/archive/2008/10/12/3062724.aspx