socket异步接收问题

Question

我用C#做一个异步接收的服务端，里面关于循环接收的这一段代码导致内存溢出：
        void keep_listening()
        {            
            while (true)
            {                                s.BeginAccept(new AsyncCallback(accept_callback), s);
                
            }
        }这里的s是socket对象。
我知道是由于异步方式不会产生阻塞，因此一直循环导致内存溢出，我看到MSDN上关于BeginAccept的代码示例中是这样写的：            while(true){
                 allDone.Reset();                 Console.WriteLine("Waiting for a connection...");
                 s.BeginAccept(new AsyncCallback(Async_Send_Receive.Listen_Callback), s);                 allDone.WaitOne();
            }但是我找不到关于这段代码中allDone的解释，连定义它的语句都没有，就这样凭空出现了。请各位指点一二，小弟初学C#

Answer 1

完整的如下
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;// State object for reading client data asynchronously
public class StateObject {
    // Client  socket.
    public Socket workSocket = null;
    // Size of receive buffer.
    public const int BufferSize = 1024;
    // Receive buffer.
    public byte[] buffer = new byte[BufferSize];
// Received data string.
    public StringBuilder sb = new StringBuilder();  
}public class AsynchronousSocketListener {
    // Thread signal.
    public static ManualResetEvent allDone = new ManualResetEvent(false);    public AsynchronousSocketListener() {
    }    public static void StartListening() {
        // Data buffer for incoming data.
        byte[] bytes = new Byte[1024];        // Establish the local endpoint for the socket.
        // The DNS name of the computer
        // running the listener is "host.contoso.com".
        IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
        IPAddress ipAddress = ipHostInfo.AddressList[0];
        IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);        // Create a TCP/IP socket.
        Socket listener = new Socket(AddressFamily.InterNetwork,
            SocketType.Stream, ProtocolType.Tcp );        // Bind the socket to the local endpoint and listen for incoming connections.
        try {
            listener.Bind(localEndPoint);
            listener.Listen(100);            while (true) {
                // Set the event to nonsignaled state.
                allDone.Reset();                // Start an asynchronous socket to listen for connections.
                Console.WriteLine("Waiting for a connection...");
                listener.BeginAccept( 
                    new AsyncCallback(AcceptCallback),
                    listener );                // Wait until a connection is made before continuing.
                allDone.WaitOne();
            }        } catch (Exception e) {
            Console.WriteLine(e.ToString());
        }        Console.WriteLine("\nPress ENTER to continue...");
        Console.Read();
        
    }    public static void AcceptCallback(IAsyncResult ar) {
        // Signal the main thread to continue.
        allDone.Set();        // Get the socket that handles the client request.
        Socket listener = (Socket) ar.AsyncState;
        Socket handler = listener.EndAccept(ar);        // Create the state object.
        StateObject state = new StateObject();
        state.workSocket = handler;
        handler.BeginReceive( state.buffer, 0, StateObject.BufferSize, 0,
            new AsyncCallback(ReadCallback), state);
    }    public static void ReadCallback(IAsyncResult ar) {
        String content = String.Empty;
        
        // Retrieve the state object and the handler socket
        // from the asynchronous state object.
        StateObject state = (StateObject) ar.AsyncState;
        Socket handler = state.workSocket;        // Read data from the client socket. 
        int bytesRead = handler.EndReceive(ar);        if (bytesRead > 0) {
            // There  might be more data, so store the data received so far.
            state.sb.Append(Encoding.ASCII.GetString(
                state.buffer,0,bytesRead));            // Check for end-of-file tag. If it is not there, read 
            // more data.
            content = state.sb.ToString();
            if (content.IndexOf("<EOF>") > -1) {
                // All the data has been read from the 
                // client. Display it on the console.
                Console.WriteLine("Read {0} bytes from socket. \n Data : {1}",
                    content.Length, content );
                // Echo the data back to the client.
                Send(handler, content);
            } else {
                // Not all data received. Get more.
                handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReadCallback), state);
            }
        }
    }
    
    private static void Send(Socket handler, String data) {
        // Convert the string data to byte data using ASCII encoding.
        byte[] byteData = Encoding.ASCII.GetBytes(data);        // Begin sending the data to the remote device.
        handler.BeginSend(byteData, 0, byteData.Length, 0,
            new AsyncCallback(SendCallback), handler);
    }    private static void SendCallback(IAsyncResult ar) {
        try {
            // Retrieve the socket from the state object.
            Socket handler = (Socket) ar.AsyncState;            // Complete sending the data to the remote device.
            int bytesSent = handler.EndSend(ar);
            Console.WriteLine("Sent {0} bytes to client.", bytesSent);            handler.Shutdown(SocketShutdown.Both);
            handler.Close();        } catch (Exception e) {
            Console.WriteLine(e.ToString());
        }
    }
    public static int Main(String[] args) {
        StartListening();
        return 0;
    }
}

Answer 2

谢谢楼上的回复，现在问题解决了，现在又在想一个新的问题：
 
 我们判断数据是否接收完一般都在发送的数据结尾加上一个特殊的标识符，服务端查找这个标识符判断。
 但是这样就必须保证正文里面不能有这个标识符，而且还增加了一次服务端的查找，C# SOCKET类里面没有内置的方法来判断数据已经接收完毕吗？

Answer 3

也可以用byte的长度,读取指定的长度,其他的舍弃
ReceivEnd()的返回值是接收的,长度,0,就是没有数据了