和accept不一样的是,AcceptEx是非阻塞的,而且在接受客户端请求前,可以发起n个AcceptEx,当连接建立时(三次握手结束时刻),会有一个接受完成包加入IOCP的完成队列,按照MSDN上说,就可以在工作线程中,通过调用GetAcceptExSockaddrs解析(parse)1)客户端发送的第一块数据,2)本地(Server)套接字地址,3)远程(Client)套接字地址
工作线程:
// 取得客户地址
int nLocalLen, nRmoteLen;
LPSOCKADDR pLocalAddr, pRemoteAddr;
m_lpfnGetAcceptExSockaddrs(
pBuffer->buff,
pBuffer->nLen - ((sizeof(sockaddr_in) + 16) * 2),
sizeof(sockaddr_in) + 16,
(SOCKADDR **)&pLocalAddr,
&nLocalLen,
(SOCKADDR **)&pRemoteAddr,
&nRmoteLen);
正如上面说当AcceptEx完成时,并且SO_UPDATE_ACCEPT_CONTEXT选项被设置时,也可以通过getsockname返回local address ,通过调用getpeername返回remote address
设置SO_UPDATE_ACCEPT_CONTEXT原因是:
When the AcceptEx function returns, the socket sAcceptSocket is in the default state for a connected socket. The socket sAcceptSocket does not inherit the properties of the socket associated with sListenSocket parameter until SO_UPDATE_ACCEPT_CONTEXT is set on the socket.
设置:
Use the setsockopt function to set the SO_UPDATE_ACCEPT_CONTEXT option, specifying sAcceptSocket as the socket handle and sListenSocket as the option value.
For example: