Destroying client-related data in a multi-client/server system - c++

Question

I will build a multi-client/server system. It's expected to work like this:
The client comunicates with the server using TCP/IP
When the client makes the connection to the server, the client sends a command string. When the server receives the command string, it parses it, do the required work and then sends a response to the client.
When the client closes the TCP connection, the server will destroy the resource related to this client.
The server is a multi-threaded program. The command receive, the command parse, the command deal and the response to the client may each be in a different thread.
Now, I want to define a CmdTcpContext class to contain the data related to the client.
class CmdTcpContext
18 {
19 public:
20 CmdTcpContext(){recv_buff_.SetRecvList(&recv_list_);}
21 ~CmdTcpContext(){}
22
23 CmdRecvBuffer & recv_buff(){return recv_buff_;}
24 SendBuffer & send_buff(){return send_buff_;}
25
26 RecvList<CmdPackage> & recv_list(){return recv_list_;}
27 RecvList<CmdPackage> & send_list(){return send_list_;}
28
29 InetAddr & inet_addr(){return addr_;}
30 SockStream & sock_stream(){return stream_;}
31
32 EventHandler * event_handler(){return handler_;}
33 void event_handler(EventHandler * eh){handler_ = eh;}
34 private:
35 SockStream stream_;
36 InetAddr addr_;
37
38 CmdRecvBuffer recv_buff_;
39 SendBuffer send_buff_;
40
41 RecvList<CmdPackage> recv_list_;
42 RecvList<CmdPackage> send_list_;
43
44 EventHandler *handler_;
45 };
My problem is: how can I destroy the CmdTcpContext object when the client closes the connection?