C# SocketAsyncEventArgs 高性能Socket代码

class Program
{
    //This variable determines the number of
    //SocketAsyncEventArg objects put in the pool of objects for receive/send.
    //The value of this variable also affects the Semaphore.
    //This app uses a Semaphore to ensure that the max # of connections
    //value does not get exceeded.
    //Max # of connections to a socket can be limited by the Windows Operating System
    //also.
    public const Int32 maxNumberOfConnections = 3000;

    //If this port # will not work for you, it's okay to change it.
    public const Int32 port = 4444;

    //You would want a buffer size larger than 25 probably, unless you know the
    //data will almost always be less than 25. It is just 25 in our test app.
    public const Int32 testBufferSize = 25;

    //This is the maximum number of asynchronous accept operations that can be
    //posted simultaneously. This determines the size of the pool of
    //SocketAsyncEventArgs objects that do accept operations. Note that this
    //is NOT the same as the maximum # of connections.
    public const Int32 maxSimultaneousAcceptOps = 10;

    //The size of the queue of incoming connections for the listen socket.
    public const Int32 backlog = 100;

    //For the BufferManager
    public const Int32 opsToPreAlloc = 2;    // 1 for receive, 1 for send

    //allows excess SAEA objects in pool.
    public const Int32 excessSaeaObjectsInPool = 1;

    //This number must be the same as the value on the client.
    //Tells what size the message prefix will be. Don't change this unless
    //you change the code, because 4 is the length of 32 bit integer, which
    //is what we are using as prefix.
    public const Int32 receivePrefixLength = 4;
    public const Int32 sendPrefixLength = 4;

    public static Int32 mainTransMissionId = 10000;
    public static Int32 startingTid; //
    public static Int32 mainSessionId = 1000000000;

    public static List listOfDataHolders;

    // To keep a record of maximum number of simultaneous connections
    // that occur while the server is running. This can be limited by operating
    // system and hardware. It will not be higher than the value that you set
    // for maxNumberOfConnections.
    public static Int32 maxSimultaneousClientsThatWereConnected = 0;

    static void Main(String[] args)
    {
        try
        {
            // Get endpoint for the listener.
            IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Any, port);

            WriteInfoToConsole(localEndPoint);

            //This object holds a lot of settings that we pass from Main method
            //to the SocketListener. In a real app, you might want to read
            //these settings from a database or windows registry settings that
            //you would create.
            SocketListenerSettings theSocketListenerSettings =
	            new SocketListenerSettings(maxNumberOfConnections,
	            excessSaeaObjectsInPool, backlog, maxSimultaneousAcceptOps,
	            receivePrefixLength, testBufferSize, sendPrefixLength, opsToPreAlloc,
	            localEndPoint);

            //instantiate the SocketListener.
            SocketListener socketListener = new SocketListener(theSocketListenerSettings);
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error: " + ex.Message);
        }
}

class SocketListener
{
    //Buffers for sockets are unmanaged by .NET.
    //So memory used for buffers gets "pinned", which makes the
    //.NET garbage collector work around it, fragmenting the memory.
    //Circumvent this problem by putting all buffers together
    //in one block in memory. Then we will assign a part of that space
    //to each SocketAsyncEventArgs object, and
    //reuse that buffer space each time we reuse the SocketAsyncEventArgs object.
    //Create a large reusable set of buffers for all socket operations.
    BufferManager theBufferManager;

    // the socket used to listen for incoming connection requests
    Socket listenSocket;

    //A Semaphore has two parameters, the initial number of available slots
    // and the maximum number of slots. We'll make them the same.
    //This Semaphore is used to keep from going over max connection #.
    //(It is not about controlling threading really here.)
    Semaphore theMaxConnectionsEnforcer;

    //an object that we pass in and which has all the settings the listener needs
    SocketListenerSettings socketListenerSettings;

    PrefixHandler prefixHandler;
    MessageHandler messageHandler;

    // pool of reusable SocketAsyncEventArgs objects for accept operations
    SocketAsyncEventArgsPool poolOfAcceptEventArgs;
    // pool of reusable SocketAsyncEventArgs objects for
    //receive and send socket operations
    SocketAsyncEventArgsPool poolOfRecSendEventArgs;

    //_______________________________________________________________________________
    // Constructor.
    public SocketListener(SocketListenerSettings theSocketListenerSettings)
    {
        this.socketListenerSettings = theSocketListenerSettings;
        this.prefixHandler = new PrefixHandler();
        this.messageHandler = new MessageHandler();

        //Allocate memory for buffers. We are using a separate buffer space for
        //receive and send, instead of sharing the buffer space, like the Microsoft
        //example does.
        this.theBufferManager = new BufferManager(this.socketListenerSettings.BufferSize
        	* this.socketListenerSettings.NumberOfSaeaForRecSend
        	* this.socketListenerSettings.OpsToPreAllocate,
        		this.socketListenerSettings.BufferSize
        	* this.socketListenerSettings.OpsToPreAllocate);

        this.poolOfRecSendEventArgs = new
        	SocketAsyncEventArgsPool(this.socketListenerSettings.NumberOfSaeaForRecSend);

        this.poolOfAcceptEventArgs = new
        	SocketAsyncEventArgsPool(this.socketListenerSettings.MaxAcceptOps);

        // Create connections count enforcer
        this.theMaxConnectionsEnforcer = new
        	Semaphore(this.socketListenerSettings.MaxConnections,
        	this.socketListenerSettings.MaxConnections);

        //Microsoft's example called these from Main method, which you
        //can easily do if you wish.
        Init();
        StartListen();
    }

    //____________________________________________________________________________
    // initializes the server by preallocating reusable buffers and
    // context objects (SocketAsyncEventArgs objects).
    //It is NOT mandatory that you preallocate them or reuse them. But, but it is
    //done this way to illustrate how the API can
    // easily be used to create reusable objects to increase server performance.

    internal void Init()
    {
        // Allocate one large byte buffer block, which all I/O operations will
        //use a piece of. This guards against memory fragmentation.
        this.theBufferManager.InitBuffer();

        // preallocate pool of SocketAsyncEventArgs objects for accept operations
        for (Int32 i = 0; i < this.socketListenerSettings.MaxAcceptOps; i++)
        {
            // add SocketAsyncEventArg to the pool
            this.poolOfAcceptEventArgs.Push(
                CreateNewSaeaForAccept(poolOfAcceptEventArgs));
        }

        //The pool that we built ABOVE is for SocketAsyncEventArgs objects that do
        // accept operations.
        //Now we will build a separate pool for SAEAs objects
        //that do receive/send operations. One reason to separate them is that accept
        //operations do NOT need a buffer, but receive/send operations do.
        //ReceiveAsync and SendAsync require
        //a parameter for buffer size in SocketAsyncEventArgs.Buffer.
        // So, create pool of SAEA objects for receive/send operations.
        SocketAsyncEventArgs eventArgObjectForPool;

        Int32 tokenId;

        for (Int32 i = 0; i < this.socketListenerSettings.NumberOfSaeaForRecSend; i++)
        {
            //Allocate the SocketAsyncEventArgs object for this loop,
            //to go in its place in the stack which will be the pool
            //for receive/send operation context objects.
            eventArgObjectForPool = new SocketAsyncEventArgs();

            // assign a byte buffer from the buffer block to
            //this particular SocketAsyncEventArg object
            this.theBufferManager.SetBuffer(eventArgObjectForPool);

            tokenId = poolOfRecSendEventArgs.AssignTokenId() + 1000000;

            //Attach the SocketAsyncEventArgs object
            //to its event handler. Since this SocketAsyncEventArgs object is
            //used for both receive and send operations, whenever either of those
            //completes, the IO_Completed method will be called.
            eventArgObjectForPool.Completed += new
            		EventHandler(IO_Completed);

            //We can store data in the UserToken property of SAEA object.
            DataHoldingUserToken theTempReceiveSendUserToken = new
            	DataHoldingUserToken(eventArgObjectForPool, eventArgObjectForPool.Offset,
            	eventArgObjectForPool.Offset + this.socketListenerSettings.BufferSize,
            	this.socketListenerSettings.ReceivePrefixLength,
            	this.socketListenerSettings.SendPrefixLength, tokenId);

            //We'll have an object that we call DataHolder, that we can remove from
            //the UserToken when we are finished with it. So, we can hang on to the
            //DataHolder, pass it to an app, serialize it, or whatever.
            theTempReceiveSendUserToken.CreateNewDataHolder();

            eventArgObjectForPool.UserToken = theTempReceiveSendUserToken;

            // add this SocketAsyncEventArg object to the pool.
            this.poolOfRecSendEventArgs.Push(eventArgObjectForPool);
    }

    //____________________________________________________________________________
    // This method is called when we need to create a new SAEA object to do
    //accept operations. The reason to put it in a separate method is so that
    //we can easily add more objects to the pool if we need to.
    //You can do that if you do NOT use a buffer in the SAEA object that does
    //the accept operations.
    internal SocketAsyncEventArgs CreateNewSaeaForAccept(SocketAsyncEventArgsPool pool)
    {
        //Allocate the SocketAsyncEventArgs object.
        SocketAsyncEventArgs acceptEventArg = new SocketAsyncEventArgs();

        //SocketAsyncEventArgs.Completed is an event, (the only event,)
        //declared in the SocketAsyncEventArgs class.
        //See http://msdn.microsoft.com/en-us/library/
        //       system.net.sockets.socketasynceventargs.completed.aspx.
        //An event handler should be attached to the event within
        //a SocketAsyncEventArgs instance when an asynchronous socket
        //operation is initiated, otherwise the application will not be able
        //to determine when the operation completes.
        //Attach the event handler, which causes the calling of the
        //AcceptEventArg_Completed object when the accept op completes.
        acceptEventArg.Completed +=
                new EventHandler<SocketAsyncEventArgs>(AcceptEventArg_Completed);

        AcceptOpUserToken theAcceptOpToken = new
        			AcceptOpUserToken(pool.AssignTokenId() + 10000);

        acceptEventArg.UserToken = theAcceptOpToken;

        return acceptEventArg;

        // accept operations do NOT need a buffer.
        //You can see that is true by looking at the
        //methods in the .NET Socket class on the Microsoft website. AcceptAsync does
        //not require a parameter for buffer size.
    }

    //____________________________________________________________________________
    // This method starts the socket server such that it is listening for
    // incoming connection requests.
    internal void StartListen()
    {
        // create the socket which listens for incoming connections
        listenSocket = new
                Socket(this.socketListenerSettings.LocalEndPoint.AddressFamily,
                SocketType.Stream, ProtocolType.Tcp);

        //bind it to the port
        listenSocket.Bind(this.socketListenerSettings.LocalEndPoint);

        // Start the listener with a backlog of however many connections.
        //"backlog" means pending connections.
        //The backlog number is the number of clients that can wait for a
        //SocketAsyncEventArg object that will do an accept operation.
        //The listening socket keeps the backlog as a queue. The backlog allows
        //for a certain # of excess clients waiting to be connected.
        //If the backlog is maxed out, then the client will receive an error when
        //trying to connect.
        //max # for backlog can be limited by the operating system.
        listenSocket.Listen(this.socketListenerSettings.Backlog);

        //Server is listening now****

        // Calls the method which will post accepts on the listening socket.
        //This call just occurs one time from this StartListen method.
        //After that the StartAccept method will be called in a loop.
        StartAccept();
    }

    //____________________________________________________________________________
    // Begins an operation to accept a connection request from the client
    internal void StartAccept()
    {
        //Get a SocketAsyncEventArgs object to accept the connection.
        SocketAsyncEventArgs acceptEventArg;
        //Get it from the pool if there is more than one in the pool.
        //We could use zero as bottom, but one is a little safer.
        if (this.poolOfAcceptEventArgs.Count > 1)
        {
            try
            {
                acceptEventArg = this.poolOfAcceptEventArgs.Pop();
            }
            //or make a new one.
            catch
            {
                acceptEventArg = CreateNewSaeaForAccept(poolOfAcceptEventArgs);
            }
        }
        //or make a new one.
        else
        {
            acceptEventArg = CreateNewSaeaForAccept(poolOfAcceptEventArgs);
        }

        // Semaphore class is used to control access to a resource or pool of
        // resources. Enter the semaphore by calling the WaitOne method, which is
        // inherited from the WaitHandle class, and release the semaphore
        // by calling the Release method. This is a mechanism to prevent exceeding
        // the max # of connections we specified. We'll do this before
        // doing AcceptAsync. If maxConnections value has been reached,
        // then the thread will pause here until the Semaphore gets released,
        // which happens in the CloseClientSocket method.
        this.theMaxConnectionsEnforcer.WaitOne();

        // Socket.AcceptAsync begins asynchronous operation to accept the connection.
        // Note the listening socket will pass info to the SocketAsyncEventArgs
        // object that has the Socket that does the accept operation.
        // If you do not create a Socket object and put it in the SAEA object
        // before calling AcceptAsync and use the AcceptSocket property to get it,
        // then a new Socket object will be created for you by .NET.
        bool willRaiseEvent = listenSocket.AcceptAsync(acceptEventArg);

        // Socket.AcceptAsync returns true if the I/O operation is pending, i.e. is
        // working asynchronously. The
        // SocketAsyncEventArgs.Completed event on the acceptEventArg parameter
        // will be raised upon completion of accept op.
        // AcceptAsync will call the AcceptEventArg_Completed
        // method when it completes, because when we created this SocketAsyncEventArgs
        // object before putting it in the pool, we set the event handler to do it.
        // AcceptAsync returns false if the I/O operation completed synchronously.
        // The SocketAsyncEventArgs.Completed event on the acceptEventArg parameter
        // will NOT be raised when AcceptAsync returns false.
        if (!willRaiseEvent)
        {
            // The code in this if (!willRaiseEvent) statement only runs
            // when the operation was completed synchronously. It is needed because
            // when Socket.AcceptAsync returns false,
            // it does NOT raise the SocketAsyncEventArgs.Completed event.
            // And we need to call ProcessAccept and pass it the SAEA object.
            // This is only when a new connection is being accepted.
            // Probably only relevant in the case of a socket error.
            ProcessAccept(acceptEventArg);
        }
    }

    //____________________________________________________________________________
    // This method is the callback method associated with Socket.AcceptAsync
    // operations and is invoked when an async accept operation completes.
    //This is only when a new connection is being accepted.
    //Notice that Socket.AcceptAsync is returning a value of true, and
    //raising the Completed event when the AcceptAsync method completes.
    private void AcceptEventArg_Completed(object sender, SocketAsyncEventArgs e)
    {
        //Any code that you put in this method will NOT be called if
        //the operation completes synchronously, which will probably happen when
        //there is some kind of socket error. It might be better to put the code
        //in the ProcessAccept method.
        ProcessAccept(e);
    }

    //____________________________________________________________________________
    //The e parameter passed from the AcceptEventArg_Completed method
    //represents the SocketAsyncEventArgs object that did
    //the accept operation. in this method we'll do the handoff from it to the
    //SocketAsyncEventArgs object that will do receive/send.
    private void ProcessAccept(SocketAsyncEventArgs acceptEventArgs)
    {
        // This is when there was an error with the accept op. That should NOT
        // be happening often. It could indicate that there is a problem with
        // that socket. If there is a problem, then we would have an infinite
        // loop here, if we tried to reuse that same socket.
        if (acceptEventArgs.SocketError != SocketError.Success)
        {
            // Loop back to post another accept op. Notice that we are NOT
            // passing the SAEA object here.
            LoopToStartAccept();

            AcceptOpUserToken theAcceptOpToken = 
		(AcceptOpUserToken)acceptEventArgs.UserToken;

            //Let's destroy this socket, since it could be bad.
            HandleBadAccept(acceptEventArgs);

            //Jump out of the method.
            return;
        }

        //Now that the accept operation completed, we can start another
        //accept operation, which will do the same. Notice that we are NOT
        //passing the SAEA object here.
        LoopToStartAccept();

        // Get a SocketAsyncEventArgs object from the pool of receive/send op
        //SocketAsyncEventArgs objects
        SocketAsyncEventArgs receiveSendEventArgs = this.poolOfRecSendEventArgs.Pop();

        //Create sessionId in UserToken.
        ((DataHoldingUserToken)receiveSendEventArgs.UserToken).CreateSessionId();

        //A new socket was created by the AcceptAsync method. The
        //SocketAsyncEventArgs object which did the accept operation has that
        //socket info in its AcceptSocket property. Now we will give
        //a reference for that socket to the SocketAsyncEventArgs
        //object which will do receive/send.
        receiveSendEventArgs.AcceptSocket = acceptEventArgs.AcceptSocket;

        //We have handed off the connection info from the
        //accepting socket to the receiving socket. So, now we can
        //put the SocketAsyncEventArgs object that did the accept operation
        //back in the pool for them. But first we will clear
        //the socket info from that object, so it will be
        //ready for a new socket when it comes out of the pool.
        acceptEventArgs.AcceptSocket = null;
        this.poolOfAcceptEventArgs.Push(acceptEventArgs);

        StartReceive(receiveSendEventArgs);
    }

    //____________________________________________________________________________
    //LoopToStartAccept method just sends us back to the beginning of the
    //StartAccept method, to start the next accept operation on the next
    //connection request that this listening socket will pass of to an
    //accepting socket. We do NOT actually need this method. You could
    //just call StartAccept() in ProcessAccept() where we called LoopToStartAccept().
    //This method is just here to help you visualize the program flow.
    private void LoopToStartAccept()
    {
        StartAccept();
    }

    //____________________________________________________________________________
    // Set the receive buffer and post a receive op.
    private void StartReceive(SocketAsyncEventArgs receiveSendEventArgs)
    {
        //Set the buffer for the receive operation.
        receiveSendEventArgs.SetBuffer(receiveSendToken.bufferOffsetReceive,
             this.socketListenerSettings.BufferSize);

        // Post async receive operation on the socket.
        bool willRaiseEvent =
             receiveSendEventArgs.AcceptSocket.ReceiveAsync(receiveSendEventArgs);

        //Socket.ReceiveAsync returns true if the I/O operation is pending. The
        //SocketAsyncEventArgs.Completed event on the e parameter will be raised
        //upon completion of the operation. So, true will cause the IO_Completed
        //method to be called when the receive operation completes.
        //That's because of the event handler we created when building
        //the pool of SocketAsyncEventArgs objects that perform receive/send.
        //It was the line that said
        //eventArgObjectForPool.Completed +=
        //     new EventHandler<SocketAsyncEventArgs>(IO_Completed);

        //Socket.ReceiveAsync returns false if I/O operation completed synchronously.
        //In that case, the SocketAsyncEventArgs.Completed event on the e parameter
        //will not be raised and the e object passed as a parameter may be
        //examined immediately after the method call
        //returns to retrieve the result of the operation.
        // It may be false in the case of a socket error.
        if (!willRaiseEvent)
        {
            //If the op completed synchronously, we need to call ProcessReceive
            //method directly. This will probably be used rarely, as you will
            //see in testing.
            ProcessReceive(receiveSendEventArgs);
        }
    }

    //____________________________________________________________________________
    // This method is called whenever a receive or send operation completes.
    // Here "e" represents the SocketAsyncEventArgs object associated
    //with the completed receive or send operation
    void IO_Completed(object sender, SocketAsyncEventArgs e)
    {
        //Any code that you put in this method will NOT be called if
        //the operation completes synchronously, which will probably happen when
        //there is some kind of socket error.

        // determine which type of operation just
        // completed and call the associated handler
        switch (e.LastOperation)
        {
            case SocketAsyncOperation.Receive:
                ProcessReceive(e);
                break;

            case SocketAsyncOperation.Send:
                ProcessSend(e);
                break;

            default:
                //This exception will occur if you code the Completed event of some
                //operation to come to this method, by mistake.
                throw new ArgumentException("The last operation completed on
                       the socket was not a receive or send");
        }
    }

    //____________________________________________________________________________
    // This method is invoked by the IO_Completed method
    // when an asynchronous receive operation completes.
    // If the remote host closed the connection, then the socket is closed.
    // Otherwise, we process the received data. And if a complete message was
    // received, then we do some additional processing, to
    // respond to the client.
    private void ProcessReceive(SocketAsyncEventArgs receiveSendEventArgs)
    {
        DataHoldingUserToken receiveSendToken =
                     (DataHoldingUserToken)receiveSendEventArgs.UserToken;

        // If there was a socket error, close the connection. This is NOT a normal
        // situation, if you get an error here.
        // In the Microsoft example code they had this error situation handled
        // at the end of ProcessReceive. Putting it here improves readability
        // by reducing nesting some.
        if (receiveSendEventArgs.SocketError != SocketError.Success)
        {
            receiveSendToken.Reset();
            CloseClientSocket(receiveSendEventArgs);

            //Jump out of the ProcessReceive method.
            return;
        }

        // If no data was received, close the connection. This is a NORMAL
        // situation that shows when the client has finished sending data.
        if (receiveSendEventArgs.BytesTransferred == 0)
        {
            receiveSendToken.Reset();
            CloseClientSocket(receiveSendEventArgs);
            return;
        }

        //The BytesTransferred property tells us how many bytes
        //we need to process.
        Int32 remainingBytesToProcess = receiveSendEventArgs.BytesTransferred;

        //If we have not got all of the prefix already,
        //then we need to work on it here.
        if (receiveSendToken.receivedPrefixBytesDoneCount <
                           this.socketListenerSettings.ReceivePrefixLength)
        {
            remainingBytesToProcess = prefixHandler.HandlePrefix(receiveSendEventArgs,
                      receiveSendToken, remainingBytesToProcess);

            if (remainingBytesToProcess == 0)
            {
                // We need to do another receive op, since we do not have
                // the message yet, but remainingBytesToProcess == 0.
                StartReceive(receiveSendEventArgs);
                //Jump out of the method.
                return;
            }
        }

        // If we have processed the prefix, we can work on the message now.
        // We'll arrive here when we have received enough bytes to read
        // the first byte after the prefix.
        bool incomingTcpMessageIsReady = messageHandler
                  .HandleMessage(receiveSendEventArgs,
                  receiveSendToken, remainingBytesToProcess);

        if (incomingTcpMessageIsReady == true)
        {
            // Pass the DataHolder object to the Mediator here. The data in
            // this DataHolder can be used for all kinds of things that an
            // intelligent and creative person like you might think of.
            receiveSendToken.theMediator.HandleData(receiveSendToken.theDataHolder);

            // Create a new DataHolder for next message.
            receiveSendToken.CreateNewDataHolder();

            //Reset the variables in the UserToken, to be ready for the
            //next message that will be received on the socket in this
            //SAEA object.
            receiveSendToken.Reset();

            receiveSendToken.theMediator.PrepareOutgoingData();
            StartSend(receiveSendToken.theMediator.GiveBack());
        }
        else
        {
            // Since we have NOT gotten enough bytes for the whole message,
            // we need to do another receive op. Reset some variables first.

            // All of the data that we receive in the next receive op will be
            // message. None of it will be prefix. So, we need to move the
            // receiveSendToken.receiveMessageOffset to the beginning of the
            // receive buffer space for this SAEA.
            receiveSendToken.receiveMessageOffset = receiveSendToken.bufferOffsetReceive;

            // Do NOT reset receiveSendToken.receivedPrefixBytesDoneCount here.
            // Just reset recPrefixBytesDoneThisOp.
            receiveSendToken.recPrefixBytesDoneThisOp = 0;

            // Since we have not gotten enough bytes for the whole message,
            // we need to do another receive op.
            StartReceive(receiveSendEventArgs);
        }
    }

    //____________________________________________________________________________
    //Post a send op.
    private void StartSend(SocketAsyncEventArgs receiveSendEventArgs)
    {
        DataHoldingUserToken receiveSendToken =
                       (DataHoldingUserToken)receiveSendEventArgs.UserToken;

        //Set the buffer. You can see on Microsoft's page at
        //http://msdn.microsoft.com/en-us/library/
        //         system.net.sockets.socketasynceventargs.setbuffer.aspx
        //that there are two overloads. One of the overloads has 3 parameters.
        //When setting the buffer, you need 3 parameters the first time you set it,
        //which we did in the Init method. The first of the three parameters
        //tells what byte array to use as the buffer. After we tell what byte array
        //to use we do not need to use the overload with 3 parameters any more.
        //(That is the whole reason for using the buffer block. You keep the same
        //byte array as buffer always, and keep it all in one block.)
        //Now we use the overload with two parameters. We tell
        // (1) the offset and
        // (2) the number of bytes to use, starting at the offset.

        //The number of bytes to send depends on whether the message is larger than
        //the buffer or not. If it is larger than the buffer, then we will have
        //to post more than one send operation. If it is less than or equal to the
        //size of the send buffer, then we can accomplish it in one send op.
        if (receiveSendToken.sendBytesRemainingCount
                       <= this.socketListenerSettings.BufferSize)
        {
            receiveSendEventArgs.SetBuffer(receiveSendToken.bufferOffsetSend,
                       receiveSendToken.sendBytesRemainingCount);
            //Copy the bytes to the buffer associated with this SAEA object.
            Buffer.BlockCopy(receiveSendToken.dataToSend,
                       receiveSendToken.bytesSentAlreadyCount,
                  receiveSendEventArgs.Buffer, receiveSendToken.bufferOffsetSend,
                  receiveSendToken.sendBytesRemainingCount);
        }
        else
        {
            //We cannot try to set the buffer any larger than its size.
            //So since receiveSendToken.sendBytesRemainingCount > BufferSize, we just
            //set it to the maximum size, to send the most data possible.
            receiveSendEventArgs.SetBuffer(receiveSendToken.bufferOffsetSend,
                        this.socketListenerSettings.BufferSize);
            //Copy the bytes to the buffer associated with this SAEA object.
            Buffer.BlockCopy(receiveSendToken.dataToSend,
                       receiveSendToken.bytesSentAlreadyCount,
                  receiveSendEventArgs.Buffer, receiveSendToken.bufferOffsetSend,
                  this.socketListenerSettings.BufferSize);

            //We'll change the value of sendUserToken.sendBytesRemainingCount
            //in the ProcessSend method.
        }

        //post asynchronous send operation
        bool willRaiseEvent =
             receiveSendEventArgs.AcceptSocket.SendAsync(receiveSendEventArgs);

        if (!willRaiseEvent)
        {
            ProcessSend(receiveSendEventArgs);
        }
    }

    //____________________________________________________________________________
    // This method is called by I/O Completed() when an asynchronous send completes.
    // If all of the data has been sent, then this method calls StartReceive
    //to start another receive op on the socket to read any additional
    // data sent from the client. If all of the data has NOT been sent, then it
    //calls StartSend to send more data.
    private void ProcessSend(SocketAsyncEventArgs receiveSendEventArgs)
    {
        DataHoldingUserToken receiveSendToken =
                       (DataHoldingUserToken)receiveSendEventArgs.UserToken;

        receiveSendToken.sendBytesRemainingCount =
                         receiveSendToken.sendBytesRemainingCount
                       - receiveSendEventArgs.BytesTransferred;
        receiveSendToken.bytesSentAlreadyCount +=
                       receiveSendEventArgs.BytesTransferred;

        if (receiveSendEventArgs.SocketError == SocketError.Success)
        {
            if (receiveSendToken.sendBytesRemainingCount == 0)
            {
                StartReceive(receiveSendEventArgs);
            }
            else
            {
                //If some of the bytes in the message have NOT been sent,
                //then we will need to post another send operation.
                //So let's loop back to StartSend().
                StartSend(receiveSendEventArgs);
            }
        }
        else
        {
            //If we are in this else-statement, there was a socket error.
            //In this example we'll just close the socket if there was a socket error
            //when receiving data from the client.
            receiveSendToken.Reset();
            CloseClientSocket(receiveSendEventArgs);
        }
   }

    //_______________________________________________________________________
    // Does the normal destroying of sockets after
    // we finish receiving and sending on a connection.
    private void CloseClientSocket(SocketAsyncEventArgs e)
    {
        var receiveSendToken = (e.UserToken as DataHoldingUserToken);

        // do a shutdown before you close the socket
        try
        {
            e.AcceptSocket.Shutdown(SocketShutdown.Both);
        }
        // throws if socket was already closed
        catch (Exception)
        {
        }

        //This method closes the socket and releases all resources, both
        //managed and unmanaged. It internally calls Dispose.
        e.AcceptSocket.Close();

        //Make sure the new DataHolder has been created for the next connection.
        //If it has, then dataMessageReceived should be null.
        if (receiveSendToken.theDataHolder.dataMessageReceived != null)
        {
            receiveSendToken.CreateNewDataHolder();
        }

        // Put the SocketAsyncEventArg back into the pool,
        // to be used by another client. This
        this.poolOfRecSendEventArgs.Push(e);

        // decrement the counter keeping track of the total number of clients
        //connected to the server, for testing
        Interlocked.Decrement(ref this.numberOfAcceptedSockets);

        //Release Semaphore so that its connection counter will be decremented.
        //This must be done AFTER putting the SocketAsyncEventArg back into the pool,
        //or you can run into problems.
        this.theMaxConnectionsEnforcer.Release();
    }

    //____________________________________________________________________________
    private void HandleBadAccept(SocketAsyncEventArgs acceptEventArgs)
    {
        var acceptOpToken = (acceptEventArgs.UserToken as AcceptOpUserToken);

        //This method closes the socket and releases all resources, both
        //managed and unmanaged. It internally calls Dispose.
        acceptEventArgs.AcceptSocket.Close();

        //Put the SAEA back in the pool.
        poolOfAcceptEventArgs.Push(acceptEventArgs);
    }
}

class PrefixHandler
{
    public Int32 HandlePrefix(SocketAsyncEventArgs e,
           DataHoldingUserToken receiveSendToken,
           Int32 remainingBytesToProcess)
    {
        //receivedPrefixBytesDoneCount tells us how many prefix bytes were
        //processed during previous receive ops which contained data for
        //this message. Usually there will NOT have been any previous
        //receive ops here. So in that case,
        //receiveSendToken.receivedPrefixBytesDoneCount would equal 0.
        //Create a byte array to put the new prefix in, if we have not
        //already done it in a previous loop.
        if (receiveSendToken.receivedPrefixBytesDoneCount == 0)
        {
            receiveSendToken.byteArrayForPrefix = new
                             Byte[receiveSendToken.receivePrefixLength];
        }

        //If this next if-statement is true, then we have received at
        //least enough bytes to have the prefix. So we can determine the
        //length of the message that we are working on.
        if (remainingBytesToProcess >= receiveSendToken.receivePrefixLength
                                - receiveSendToken.receivedPrefixBytesDoneCount)
        {
            //Now copy that many bytes to byteArrayForPrefix.
            //We can use the variable receiveMessageOffset as our main
            //index to show which index to get data from in the TCP
            //buffer.
            Buffer.BlockCopy(e.Buffer, receiveSendToken.receiveMessageOffset
                      - receiveSendToken.receivePrefixLength
                      + receiveSendToken.receivedPrefixBytesDoneCount,
                receiveSendToken.byteArrayForPrefix,
                receiveSendToken.receivedPrefixBytesDoneCount,
                receiveSendToken.receivePrefixLength
                      - receiveSendToken.receivedPrefixBytesDoneCount);

            remainingBytesToProcess = remainingBytesToProcess
                      - receiveSendToken.receivePrefixLength
                      + receiveSendToken.receivedPrefixBytesDoneCount;

            receiveSendToken.recPrefixBytesDoneThisOp =
                receiveSendToken.receivePrefixLength
                      - receiveSendToken.receivedPrefixBytesDoneCount;

            receiveSendToken.receivedPrefixBytesDoneCount =
                receiveSendToken.receivePrefixLength;

            receiveSendToken.lengthOfCurrentIncomingMessage =
                BitConverter.ToInt32(receiveSendToken.byteArrayForPrefix, 0);

            return remainingBytesToProcess;
        }

        //This next else-statement deals with the situation
        //where we have some bytes
        //of this prefix in this receive operation, but not all.
        else
        {
            //Write the bytes to the array where we are putting the
            //prefix data, to save for the next loop.
            Buffer.BlockCopy(e.Buffer, receiveSendToken.receiveMessageOffset
                        - receiveSendToken.receivePrefixLength
                        + receiveSendToken.receivedPrefixBytesDoneCount,
                    receiveSendToken.byteArrayForPrefix,
                    receiveSendToken.receivedPrefixBytesDoneCount,
                    remainingBytesToProcess);

            receiveSendToken.recPrefixBytesDoneThisOp = remainingBytesToProcess;
            receiveSendToken.receivedPrefixBytesDoneCount += remainingBytesToProcess;
            remainingBytesToProcess = 0;
        }

        // This section is needed when we have received
        // an amount of data exactly equal to the amount needed for the prefix,
        // but no more. And also needed with the situation where we have received
        // less than the amount of data needed for prefix.
        if (remainingBytesToProcess == 0)
        {
            receiveSendToken.receiveMessageOffset =
            	receiveSendToken.receiveMessageOffset - 
		receiveSendToken.recPrefixBytesDoneThisOp;
            receiveSendToken.recPrefixBytesDoneThisOp = 0;
        }
        return remainingBytesToProcess;
    }
}

class MessageHandler
{
    public bool HandleMessage(SocketAsyncEventArgs receiveSendEventArgs,
                DataHoldingUserToken receiveSendToken,
                Int32 remainingBytesToProcess)
    {
        bool incomingTcpMessageIsReady = false;

        //Create the array where we'll store the complete message,
        //if it has not been created on a previous receive op.
        if (receiveSendToken.receivedMessageBytesDoneCount == 0)
        {
            receiveSendToken.theDataHolder.dataMessageReceived =
                   new Byte[receiveSendToken.lengthOfCurrentIncomingMessage];
        }

        // Remember there is a receiveSendToken.receivedPrefixBytesDoneCount
        // variable, which allowed us to handle the prefix even when it
        // requires multiple receive ops. In the same way, we have a
        // receiveSendToken.receivedMessageBytesDoneCount variable, which
        // helps us handle message data, whether it requires one receive
        // operation or many.
        if (remainingBytesToProcess + receiveSendToken.receivedMessageBytesDoneCount
                   == receiveSendToken.lengthOfCurrentIncomingMessage)
        {
            // If we are inside this if-statement, then we got
            // the end of the message. In other words,
            // the total number of bytes we received for this message matched the
            // message length value that we got from the prefix.

            // Write/append the bytes received to the byte array in the
            // DataHolder object that we are using to store our data.
            Buffer.BlockCopy(receiveSendEventArgs.Buffer,
                receiveSendToken.receiveMessageOffset,
                receiveSendToken.theDataHolder.dataMessageReceived,
                receiveSendToken.receivedMessageBytesDoneCount,
                remainingBytesToProcess);

            incomingTcpMessageIsReady = true;
        }
        else
        {
            // If we are inside this else-statement, then that means that we
            // need another receive op. We still haven't got the whole message,
            // even though we have examined all the data that was received.
            // Not a problem. In SocketListener.ProcessReceive we will just call
            // StartReceive to do another receive op to receive more data.

            Buffer.BlockCopy(receiveSendEventArgs.Buffer,
                    receiveSendToken.receiveMessageOffset,
                    receiveSendToken.theDataHolder.dataMessageReceived,
                    receiveSendToken.receivedMessageBytesDoneCount,
                    remainingBytesToProcess);

            receiveSendToken.receiveMessageOffset =
                    receiveSendToken.receiveMessageOffset -
                    receiveSendToken.recPrefixBytesDoneThisOp;

            receiveSendToken.receivedMessageBytesDoneCount += remainingBytesToProcess;
        }
        return incomingTcpMessageIsReady;
    }
}

class BufferManager
{
    // This class creates a single large buffer which can be divided up
    // and assigned to SocketAsyncEventArgs objects for use with each
    // socket I/O operation.
    // This enables buffers to be easily reused and guards against
    // fragmenting heap memory.
    //
    //This buffer is a byte array which the Windows TCP buffer can copy its data to.

    // the total number of bytes controlled by the buffer pool
    Int32 totalBytesInBufferBlock;

    // Byte array maintained by the Buffer Manager.
    byte[] bufferBlock;
    Stack<int> freeIndexPool;
    Int32 currentIndex;
    Int32 bufferBytesAllocatedForEachSaea;

    public BufferManager(Int32 totalBytes, Int32 totalBufferBytesInEachSaeaObject)
    {
        totalBytesInBufferBlock = totalBytes;
        this.currentIndex = 0;
        this.bufferBytesAllocatedForEachSaea = totalBufferBytesInEachSaeaObject;
        this.freeIndexPool = new Stack<int>();
    }

    // Allocates buffer space used by the buffer pool
    internal void InitBuffer()
    {
        // Create one large buffer block.
        this.bufferBlock = new byte[totalBytesInBufferBlock];
    }

    // Divide that one large buffer block out to each SocketAsyncEventArg object.
    // Assign a buffer space from the buffer block to the
    // specified SocketAsyncEventArgs object.
    //
    // returns true if the buffer was successfully set, else false
    internal bool SetBuffer(SocketAsyncEventArgs args)
    {
        if (this.freeIndexPool.Count > 0)
        {
            //This if-statement is only true if you have called the FreeBuffer
            //method previously, which would put an offset for a buffer space
            //back into this stack.
            args.SetBuffer(this.bufferBlock, this.freeIndexPool.Pop(),
                       this.bufferBytesAllocatedForEachSaea);
        }
        else
        {
            //Inside this else-statement is the code that is used to set the
            //buffer for each SAEA object when the pool of SAEA objects is built
            //in the Init method.
            if ((totalBytesInBufferBlock - this.bufferBytesAllocatedForEachSaea) <
                       this.currentIndex)
            {
                return false;
            }
            args.SetBuffer(this.bufferBlock, this.currentIndex,
                             this.bufferBytesAllocatedForEachSaea);
            this.currentIndex += this.bufferBytesAllocatedForEachSaea;
        }
        return true;
    }

    // Removes the buffer from a SocketAsyncEventArg object. This frees the
    // buffer back to the buffer pool. Try NOT to use the FreeBuffer method,
    // unless you need to destroy the SAEA object, or maybe in the case
    // of some exception handling. Instead, on the server
    // keep the same buffer space assigned to one SAEA object for the duration of
    // this app's running.
    internal void FreeBuffer(SocketAsyncEventArgs args)
    {
        this.freeIndexPool.Push(args.Offset);
        args.SetBuffer(null, 0, 0);
    }
}

class DataHoldingUserToken
{
    internal Mediator theMediator;
    internal DataHolder theDataHolder;
    internal readonly Int32 bufferOffsetReceive;
    internal readonly Int32 permanentReceiveMessageOffset;
    internal readonly Int32 bufferOffsetSend;
    private Int32 idOfThisObject;

    internal Int32 lengthOfCurrentIncomingMessage;

    //receiveMessageOffset is used to mark the byte position where the message
    //begins in the receive buffer. This value can sometimes be out of
    //bounds for the data stream just received. But, if it is out of bounds, the
    //code will not access it.
    internal Int32 receiveMessageOffset;
    internal Byte[] byteArrayForPrefix;
    internal readonly Int32 receivePrefixLength;
    internal Int32 receivedPrefixBytesDoneCount = 0;
    internal Int32 receivedMessageBytesDoneCount = 0;
    //This variable will be needed to calculate the value of the
    //receiveMessageOffset variable in one situation. Notice that the
    //name is similar but the usage is different from the variable
    //receiveSendToken.receivePrefixBytesDone.
    internal Int32 recPrefixBytesDoneThisOp = 0;

    internal Int32 sendBytesRemainingCount;
    internal readonly Int32 sendPrefixLength;
    internal Byte[] dataToSend;
    internal Int32 bytesSentAlreadyCount;

    //The session ID correlates with all the data sent in a connected session.
    //It is different from the transmission ID in the DataHolder, which relates
    //to one TCP message. A connected session could have many messages, if you
    //set up your app to allow it.
    private Int32 sessionId;

    public DataHoldingUserToken(SocketAsyncEventArgs e, Int32 rOffset, Int32 sOffset,
           Int32 receivePrefixLength, Int32 sendPrefixLength, Int32 identifier)
    {
        this.idOfThisObject = identifier;

        //Create a Mediator that has a reference to the SAEA object.
        this.theMediator = new Mediator(e);
        this.bufferOffsetReceive = rOffset;
        this.bufferOffsetSend = sOffset;
        this.receivePrefixLength = receivePrefixLength;
        this.sendPrefixLength = sendPrefixLength;
        this.receiveMessageOffset = rOffset + receivePrefixLength;
        this.permanentReceiveMessageOffset = this.receiveMessageOffset;
    }

    //Let's use an ID for this object during testing, just so we can see what
    //is happening better if we want to.
    public Int32 TokenId
    {
        get
        {
            return this.idOfThisObject;
        }
    }

    internal void CreateNewDataHolder()
    {
        theDataHolder = new DataHolder();
    }

    //Used to create sessionId variable in DataHoldingUserToken.
    //Called in ProcessAccept().
    internal void CreateSessionId()
    {
        sessionId = Interlocked.Increment(ref Program.mainSessionId);
    }

    public Int32 SessionId
    {
        get
        {
            return this.sessionId;
        }
    }

    public void Reset()
    {
        this.receivedPrefixBytesDoneCount = 0;
        this.receivedMessageBytesDoneCount = 0;
        this.recPrefixBytesDoneThisOp = 0;
        this.receiveMessageOffset = this.permanentReceiveMessageOffset;
    }
}

class Mediator
{
    private IncomingDataPreparer theIncomingDataPreparer;
    private OutgoingDataPreparer theOutgoingDataPreparer;
    private DataHolder theDataHolder;
    private SocketAsyncEventArgs saeaObject;

    public Mediator(SocketAsyncEventArgs e)
    {
        this.saeaObject = e;
        this.theIncomingDataPreparer = new IncomingDataPreparer(saeaObject);
        this.theOutgoingDataPreparer = new OutgoingDataPreparer();
    }

    internal void HandleData(DataHolder incomingDataHolder)
    {
        theDataHolder = theIncomingDataPreparer.HandleReceivedData
                       (incomingDataHolder, this.saeaObject);
    }

    internal void PrepareOutgoingData()
    {
        theOutgoingDataPreparer.PrepareOutgoingData(saeaObject, theDataHolder);
    }

    internal SocketAsyncEventArgs GiveBack()
    {
        return saeaObject;
    }
}

class IncomingDataPreparer
{
    private DataHolder theDataHolder;
    private SocketAsyncEventArgs theSaeaObject;

    public IncomingDataPreparer(SocketAsyncEventArgs e)
    {
        this.theSaeaObject = e;
    }

    private Int32 ReceivedTransMissionIdGetter()
    {
        Int32 receivedTransMissionId =
              Interlocked.Increment(ref Program.mainTransMissionId);
        return receivedTransMissionId;
    }

    private EndPoint GetRemoteEndpoint()
    {
        return this.theSaeaObject.AcceptSocket.RemoteEndPoint;
    }

    internal DataHolder HandleReceivedData(DataHolder incomingDataHolder,
                        SocketAsyncEventArgs theSaeaObject)
    {
        DataHoldingUserToken receiveToken =
                       (DataHoldingUserToken)theSaeaObject.UserToken;
        theDataHolder = incomingDataHolder;
        theDataHolder.sessionId = receiveToken.SessionId;
        theDataHolder.receivedTransMissionId =
                      this.ReceivedTransMissionIdGetter();
        theDataHolder.remoteEndpoint = this.GetRemoteEndpoint();
        this.AddDataHolder();
        return theDataHolder;
    }

    private void AddDataHolder()
    {
        lock (Program.lockerForList)
        {
            Program.listOfDataHolders.Add(theDataHolder);
        }
    }
}

class OutgoingDataPreparer
{
    private DataHolder theDataHolder;

    internal void PrepareOutgoingData(SocketAsyncEventArgs e,
                       DataHolder handledDataHolder)
    {
        DataHoldingUserToken theUserToken = (DataHoldingUserToken)e.UserToken;
        theDataHolder = handledDataHolder;

        //In this example code, we will send back the receivedTransMissionId,
        // followed by the
        //message that the client sent to the server. And we must
        //prefix it with the length of the message. So we put 3
        //things into the array.
        // 1) prefix,
        // 2) receivedTransMissionId,
        // 3) the message that we received from the client, which
        // we stored in our DataHolder until we needed it.
        //That is our communication protocol. The client must know the protocol.

        //Convert the receivedTransMissionId to byte array.
        Byte[] idByteArray = BitConverter.GetBytes
                       (theDataHolder.receivedTransMissionId);

        //Determine the length of all the data that we will send back.
        Int32 lengthOfCurrentOutgoingMessage = idByteArray.Length
                       + theDataHolder.dataMessageReceived.Length;

        //So, now we convert the length integer into a byte array.
        //Aren't byte arrays wonderful? Maybe you'll dream about byte arrays tonight!
        Byte[] arrayOfBytesInPrefix = BitConverter.GetBytes
                       (lengthOfCurrentOutgoingMessage);

        //Create the byte array to send.
        theUserToken.dataToSend = new Byte[theUserToken.sendPrefixLength
                       + lengthOfCurrentOutgoingMessage];

        //Now copy the 3 things to the theUserToken.dataToSend.
        Buffer.BlockCopy(arrayOfBytesInPrefix, 0, theUserToken.dataToSend,
                       0, theUserToken.sendPrefixLength);
        Buffer.BlockCopy(idByteArray, 0, theUserToken.dataToSend,
                       theUserToken.sendPrefixLength, idByteArray.Length);
        //The message that the client sent is already in a byte array, in DataHolder.
        Buffer.BlockCopy(theDataHolder.dataMessageReceived, 0,
               theUserToken.dataToSend, theUserToken.sendPrefixLength
               + idByteArray.Length, theDataHolder.dataMessageReceived.Length);

        theUserToken.sendBytesRemainingCount =
                theUserToken.sendPrefixLength + lengthOfCurrentOutgoingMessage;
        theUserToken.bytesSentAlreadyCount = 0;
    }
}

class DataHolder
{
    //Remember, if a socket uses a byte array for its buffer, that byte array is
    //unmanaged in .NET and can cause memory fragmentation. So, first write to the
    //buffer block used by the SAEA object. Then, you can copy that data to another
    //byte array, if you need to keep it or work on it, and want to be able to put
    //the SAEA object back in the pool quickly, or continue with the data
    //transmission quickly.
    //DataHolder has this byte array to which you can copy the data.
    internal Byte[] dataMessageReceived;

    internal Int32 receivedTransMissionId;

    internal Int32 sessionId;

    //for testing. With a packet analyzer this can help you see specific connections.
    internal EndPoint remoteEndpoint;
}

internal sealed class SocketAsyncEventArgsPool
{
    //just for assigning an ID so we can watch our objects while testing.
    private Int32 nextTokenId = 0;

    // Pool of reusable SocketAsyncEventArgs objects.
    Stack pool;

    // initializes the object pool to the specified size.
    // "capacity" = Maximum number of SocketAsyncEventArgs objects
    internal SocketAsyncEventArgsPool(Int32 capacity)
    {
        this.pool = new Stack(capacity);
    }

    // The number of SocketAsyncEventArgs instances in the pool.
    internal Int32 Count
    {
        get { return this.pool.Count; }
    }

    internal Int32 AssignTokenId()
    {
        Int32 tokenId = Interlocked.Increment(ref nextTokenId);
        return tokenId;
    }

    // Removes a SocketAsyncEventArgs instance from the pool.
    // returns SocketAsyncEventArgs removed from the pool.
    internal SocketAsyncEventArgs Pop()
    {
        lock (this.pool)
        {
            return this.pool.Pop();
        }
    }

    // Add a SocketAsyncEventArg instance to the pool.
    // "item" = SocketAsyncEventArgs instance to add to the pool.
    internal void Push(SocketAsyncEventArgs item)
    {
        if (item == null)
        {
            throw new ArgumentNullException("Items added to a
            		SocketAsyncEventArgsPool cannot be null");
        }
        lock (this.pool)
        {
            this.pool.Push(item);
        }
    }
}

class SocketListenerSettings
{
    // the maximum number of connections the sample is designed to handle simultaneously
    private Int32 maxConnections;

    // this variable allows us to create some extra SAEA objects for the pool,
    // if we wish.
    private Int32 numberOfSaeaForRecSend;

    // max # of pending connections the listener can hold in queue
    private Int32 backlog;

    // tells us how many objects to put in pool for accept operations
    private Int32 maxSimultaneousAcceptOps;

    // buffer size to use for each socket receive operation
    private Int32 receiveBufferSize;

    // length of message prefix for receive ops
    private Int32 receivePrefixLength;

    // length of message prefix for send ops
    private Int32 sendPrefixLength;

    // See comments in buffer manager.
    private Int32 opsToPreAllocate;

    // Endpoint for the listener.
    private IPEndPoint localEndPoint;

    public SocketListenerSettings(Int32 maxConnections,
    Int32 excessSaeaObjectsInPool, Int32 backlog, Int32 maxSimultaneousAcceptOps,
    Int32 receivePrefixLength, Int32 receiveBufferSize, Int32 sendPrefixLength,
    Int32 opsToPreAlloc, IPEndPoint theLocalEndPoint)
    {
        this.maxConnections = maxConnections;
        this.numberOfSaeaForRecSend = maxConnections + excessSaeaObjectsInPool;
        this.backlog = backlog;
        this.maxSimultaneousAcceptOps = maxSimultaneousAcceptOps;
        this.receivePrefixLength = receivePrefixLength;
        this.receiveBufferSize = receiveBufferSize;
        this.sendPrefixLength = sendPrefixLength;
        this.opsToPreAllocate = opsToPreAlloc;
        this.localEndPoint = theLocalEndPoint;
    }

    public Int32 MaxConnections
    {
        get
        {
            return this.maxConnections;
        }
    }
    public Int32 NumberOfSaeaForRecSend
    {
        get
        {
            return this.numberOfSaeaForRecSend;
        }
    }
    public Int32 Backlog
    {
        get
        {
            return this.backlog;
        }
    }
    public Int32 MaxAcceptOps
    {
        get
        {
            return this.maxSimultaneousAcceptOps;
        }
    }
    public Int32 ReceivePrefixLength
    {
        get
        {
            return this.receivePrefixLength;
        }
    }
    public Int32 BufferSize
    {
        get
        {
            return this.receiveBufferSize;
        }
    }
    public Int32 SendPrefixLength
    {
        get
        {
            return this.sendPrefixLength;
        }
    }
    public Int32 OpsToPreAllocate
    {
        get
        {
            return this.opsToPreAllocate;
        }
    }
    public IPEndPoint LocalEndPoint
    {
        get
        {
            return this.localEndPoint;
        }
    }
}