目标：利用Reactor框架构建一个能处理多个连接的服务器。
我们的方案：从 ACE_Event_Handler 类派生两个事件处理类，分工，"连接接受"和“连接服务"。

//用于接受连接的事件处理器（反应器）
class ClientAcceptor : public ACE_Event_Handler
{
public:
virtual ~ClientAcceptor(void)
{
this->handle_close(ACE_INVALID_HANDLE,0);
}
int open(const ACE_INET_Addr& listen_addr)
{
if (this->acceptor_.open(listen_addr,1) == -1)
ACE_ERROR_RETURN((LM_ERROR,
ACE_TEXT("%p/n"),
ACE_TEXT("acceptor.open")),
-1);

//针对接受事件向反应器登记
return this->reactor()->register_handler(this,ACE_Event_Handler::ACCEPT_MASK);
}
protected:
ACE_SOCK_Acceptor acceptor_;
public:
// Get this handler's I/O handle.
virtual ACE_HANDLE get_handle(void) const
{
return this->acceptor_.get_handle();
}
// Called when a connection is ready to accept.
virtual int handle_input(ACE_HANDLE fd)
{
//ClientService* client;
//ACE_NEW_RETURN(client,ClientService,-1);
ClientService *client = new ClientService();
auto_ptr<ClientService> p(client);//这个auto_ptr应该具有引用计数的功能

if (this->acceptor_.accept(client->peer()) == -1)
return -1;
p.release();
client->reactor(this->reactor());
if (client->open() == -1)
client->handle_close(ACE_INVALID_HANDLE,0);
return 0;
}
// Called when this handler is removed from the ACE_Reactor.
virtual int handle_close(ACE_HANDLE handle,ACE_Reactor_Mask close_mask)
{
if (this->acceptor_.get_handle() != ACE_INVALID_HANDLE)
{
ACE_Reactor_Mask m = ACE_Event_Handler::ACCEPT_MASK | ACE_Event_Handler::DONT_CALL;
this->reactor()->remove_handler(this,m);
this->acceptor_.close();
}
return 0;
}
};

//服务处理器
//每个连接使用单独的服务处理器对象
class ClientService : public ACE_Event_Handler
{
protected:
ACE_SOCK_Stream sock_;
public:
//返回ACE_SOCK_Stream对象引用
ACE_SOCK_Stream& peer(void)
{
return this->sock_;
}
int open(void)
{
//针对输入事件向反应器登记
return this->reactor()->register_handler(this,ACE_Event_Handler::READ_MASK);
}
// Get this handler's I/O handle.
virtual ACE_HANDLE get_handle(void) const
{
return this->sock_.get_handle();
}
// Called when input is available from the client.
virtual int handle_input(ACE_HANDLE fd)
{
const size_t INPUT_SIZE = 4096;
char buffer[INPUT_SIZE];
ssize_t recv_cnt;
if ((recv_cnt = this->sock_.recv(buffer,sizeof (buffer))) <= 0)
{
//接受到的数据为0个字节，表明对端已关闭其socket。
//返回-1，表示工作已完成。
return -1;
}

//在这里你可以对接收的数据进行处理
//...

return 0;
}
// Called when this handler is removed from the ACE_Reactor.
virtual int handle_close(ACE_HANDLE handle,ACE_Reactor_Mask close_mask)
{
mask = ACE_Event_Handler::ALL_EVENTS_MASK |
ACE_Event_Handler::DONT_CALL;
this->reactor()->remove_handler(this,mask);
this->sock_.close();
delete this; return 0; } }; //好了构建好了你的应用，你可以启动它了。 ACE_INET_Addr addr_to_listen(50000,ACE_LOCALHOST); ClientAcceptor acceptor; acceptor.reactor(ACE_Reactor::instance()); //开始监听，向反应器进行登记，请求它在可以接受新连接时回调自己。 if (acceptor.open(addr_to_listen) == -1) return 1; //进入反应器事件循环 ACE_Reactor::instance()->run_reactor_event_loop();