SocketAsyncEventArgs SocketAsyncEventArgs SocketAsyncEventArgs SocketAsyncEventArgs Class

Definición

Representa una operación de socket asincrónico.Represents an asynchronous socket operation.

public ref class SocketAsyncEventArgs : EventArgs, IDisposable
public class SocketAsyncEventArgs : EventArgs, IDisposable
type SocketAsyncEventArgs = class
    inherit EventArgs
    interface IDisposable
Public Class SocketAsyncEventArgs
Inherits EventArgs
Implements IDisposable
Herencia
SocketAsyncEventArgsSocketAsyncEventArgsSocketAsyncEventArgsSocketAsyncEventArgs
Implementaciones

Ejemplos

En el ejemplo de código siguiente se implementa la lógica de conexión para el servidor de socket que usa el SocketAsyncEventArgs clase.The following code example implements the connection logic for the socket server that uses the SocketAsyncEventArgs class. Después de aceptar una conexión, todos los datos leídos desde el cliente se envía al cliente.After accepting a connection, all data read from the client is sent back to the client. La lectura y eco al modelo del cliente continúa hasta que el cliente se desconecta.The read and echo back to the client pattern is continued until the client disconnects. La clase BufferManager que se usa en este ejemplo se muestra en el ejemplo de código para el SetBuffer(Byte[], Int32, Int32) método.The BufferManager class that is used by this example is displayed in the code example for the SetBuffer(Byte[], Int32, Int32) method. La clase SocketAsyncEventArgsPool que se usa en este ejemplo se muestra en el ejemplo de código para el SocketAsyncEventArgs constructor.The SocketAsyncEventArgsPool class that is used in this example is displayed in the code example for the SocketAsyncEventArgs constructor.

// Implements the connection logic for the socket server.  
// After accepting a connection, all data read from the client 
// is sent back to the client. The read and echo back to the client pattern 
// is continued until the client disconnects.
class Server
{
    private int m_numConnections;   // the maximum number of connections the sample is designed to handle simultaneously 
    private int m_receiveBufferSize;// buffer size to use for each socket I/O operation 
    BufferManager m_bufferManager;  // represents a large reusable set of buffers for all socket operations
    const int opsToPreAlloc = 2;    // read, write (don't alloc buffer space for accepts)
    Socket listenSocket;            // the socket used to listen for incoming connection requests
    // pool of reusable SocketAsyncEventArgs objects for write, read and accept socket operations
    SocketAsyncEventArgsPool m_readWritePool;
    int m_totalBytesRead;           // counter of the total # bytes received by the server
    int m_numConnectedSockets;      // the total number of clients connected to the server 
    Semaphore m_maxNumberAcceptedClients;

    // Create an uninitialized server instance.  
    // To start the server listening for connection requests
    // call the Init method followed by Start method 
    //
    // <param name="numConnections">the maximum number of connections the sample is designed to handle simultaneously</param>
    // <param name="receiveBufferSize">buffer size to use for each socket I/O operation</param>
    public Server(int numConnections, int receiveBufferSize)
    {
        m_totalBytesRead = 0;
        m_numConnectedSockets = 0;
        m_numConnections = numConnections;
        m_receiveBufferSize = receiveBufferSize;
        // allocate buffers such that the maximum number of sockets can have one outstanding read and 
        //write posted to the socket simultaneously  
        m_bufferManager = new BufferManager(receiveBufferSize * numConnections * opsToPreAlloc,
            receiveBufferSize);
  
        m_readWritePool = new SocketAsyncEventArgsPool(numConnections);
        m_maxNumberAcceptedClients = new Semaphore(numConnections, numConnections); 
    }

    // Initializes the server by preallocating reusable buffers and 
    // context objects.  These objects do not need to be preallocated 
    // or reused, but it is done this way to illustrate how the API can 
    // easily be used to create reusable objects to increase server performance.
    //
    public void Init()
    {
        // Allocates one large byte buffer which all I/O operations use a piece of.  This gaurds 
        // against memory fragmentation
        m_bufferManager.InitBuffer();

        // preallocate pool of SocketAsyncEventArgs objects
        SocketAsyncEventArgs readWriteEventArg;

        for (int i = 0; i < m_numConnections; i++)
        {
            //Pre-allocate a set of reusable SocketAsyncEventArgs
            readWriteEventArg = new SocketAsyncEventArgs();
            readWriteEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(IO_Completed);
            readWriteEventArg.UserToken = new AsyncUserToken();

            // assign a byte buffer from the buffer pool to the SocketAsyncEventArg object
            m_bufferManager.SetBuffer(readWriteEventArg);

            // add SocketAsyncEventArg to the pool
            m_readWritePool.Push(readWriteEventArg);
        }

    }

    // Starts the server such that it is listening for 
    // incoming connection requests.    
    //
    // <param name="localEndPoint">The endpoint which the server will listening 
    // for connection requests on</param>
    public void Start(IPEndPoint localEndPoint)
    {
        // create the socket which listens for incoming connections
        listenSocket = new Socket(localEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
        listenSocket.Bind(localEndPoint);
        // start the server with a listen backlog of 100 connections
        listenSocket.Listen(100);
        
        // post accepts on the listening socket
        StartAccept(null);            

        //Console.WriteLine("{0} connected sockets with one outstanding receive posted to each....press any key", m_outstandingReadCount);
        Console.WriteLine("Press any key to terminate the server process....");
        Console.ReadKey();
    }


    // Begins an operation to accept a connection request from the client 
    //
    // <param name="acceptEventArg">The context object to use when issuing 
    // the accept operation on the server's listening socket</param>
    public void StartAccept(SocketAsyncEventArgs acceptEventArg)
    {
        if (acceptEventArg == null)
        {
            acceptEventArg = new SocketAsyncEventArgs();
            acceptEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(AcceptEventArg_Completed);
        }
        else
        {
            // socket must be cleared since the context object is being reused
            acceptEventArg.AcceptSocket = null;
        }

        m_maxNumberAcceptedClients.WaitOne();
        bool willRaiseEvent = listenSocket.AcceptAsync(acceptEventArg);
        if (!willRaiseEvent)
        {
            ProcessAccept(acceptEventArg);
        }
    }

    // This method is the callback method associated with Socket.AcceptAsync 
    // operations and is invoked when an accept operation is complete
    //
    void AcceptEventArg_Completed(object sender, SocketAsyncEventArgs e)
    {
        ProcessAccept(e);
    }

    private void ProcessAccept(SocketAsyncEventArgs e)
    {
        Interlocked.Increment(ref m_numConnectedSockets);
        Console.WriteLine("Client connection accepted. There are {0} clients connected to the server",
            m_numConnectedSockets);

        // Get the socket for the accepted client connection and put it into the 
        //ReadEventArg object user token
        SocketAsyncEventArgs readEventArgs = m_readWritePool.Pop();
        ((AsyncUserToken)readEventArgs.UserToken).Socket = e.AcceptSocket;

        // As soon as the client is connected, post a receive to the connection
        bool willRaiseEvent = e.AcceptSocket.ReceiveAsync(readEventArgs);
        if(!willRaiseEvent){
            ProcessReceive(readEventArgs);
        }

        // Accept the next connection request
        StartAccept(e);
    }

    // This method is called whenever a receive or send operation is completed on a socket 
    //
    // <param name="e">SocketAsyncEventArg associated with the completed receive operation</param>
    void IO_Completed(object sender, SocketAsyncEventArgs e)
    {
        // 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:
                throw new ArgumentException("The last operation completed on the socket was not a receive or send");
        }       

    }
    
    // This method is invoked when an asynchronous receive operation completes. 
    // If the remote host closed the connection, then the socket is closed.  
    // If data was received then the data is echoed back to the client.
    //
    private void ProcessReceive(SocketAsyncEventArgs e)
    {
        // check if the remote host closed the connection
        AsyncUserToken token = (AsyncUserToken)e.UserToken;
        if (e.BytesTransferred > 0 && e.SocketError == SocketError.Success)
        {
            //increment the count of the total bytes receive by the server
            Interlocked.Add(ref m_totalBytesRead, e.BytesTransferred);
            Console.WriteLine("The server has read a total of {0} bytes", m_totalBytesRead);
            
            //echo the data received back to the client
            e.SetBuffer(e.Offset, e.BytesTransferred);
            bool willRaiseEvent = token.Socket.SendAsync(e);
            if (!willRaiseEvent)
            {
                ProcessSend(e);
            }
          
        }
        else
        {
            CloseClientSocket(e);
        }
    }

    // This method is invoked when an asynchronous send operation completes.  
    // The method issues another receive on the socket to read any additional 
    // data sent from the client
    //
    // <param name="e"></param>
    private void ProcessSend(SocketAsyncEventArgs e)
    {
        if (e.SocketError == SocketError.Success)
        {
            // done echoing data back to the client
            AsyncUserToken token = (AsyncUserToken)e.UserToken;
            // read the next block of data send from the client
            bool willRaiseEvent = token.Socket.ReceiveAsync(e);
            if (!willRaiseEvent)
            {
                ProcessReceive(e);
            }
        }
        else
        {
            CloseClientSocket(e);
        }
    }

    private void CloseClientSocket(SocketAsyncEventArgs e)
    {
        AsyncUserToken token = e.UserToken as AsyncUserToken;

        // close the socket associated with the client
        try
        {
            token.Socket.Shutdown(SocketShutdown.Send);
        }
        // throws if client process has already closed
        catch (Exception) { }
        token.Socket.Close();

        // decrement the counter keeping track of the total number of clients connected to the server
        Interlocked.Decrement(ref m_numConnectedSockets);
        
        // Free the SocketAsyncEventArg so they can be reused by another client
        m_readWritePool.Push(e);
        
        m_maxNumberAcceptedClients.Release();
        Console.WriteLine("A client has been disconnected from the server. There are {0} clients connected to the server", m_numConnectedSockets);
    }

}    

Comentarios

El SocketAsyncEventArgs clase forma parte de un conjunto de mejoras para el System.Net.Sockets.Socket clases que proporcionan un patrón asincrónico alternativo que se puede usar las aplicaciones de socket de alto rendimiento especializadas.The SocketAsyncEventArgs class is part of a set of enhancements to the System.Net.Sockets.Socket class that provide an alternative asynchronous pattern that can be used by specialized high-performance socket applications. Esta clase se diseñó específicamente para aplicaciones de servidor de red que necesitan un alto rendimiento.This class was specifically designed for network server applications that require high performance. Una aplicación puede usar el patrón asincrónico mejorado exclusivamente o solo en áreas activas (por ejemplo, cuando se reciben grandes cantidades de datos) de destino.An application can use the enhanced asynchronous pattern exclusively or only in targeted hot areas (for example, when receiving large amounts of data).

La característica principal de estas mejoras es la elusión de la asignación y la sincronización repetidas de objetos durante la E/S de socket asincrónico de gran volumen.The main feature of these enhancements is the avoidance of the repeated allocation and synchronization of objects during high-volume asynchronous socket I/O. El patrón de diseño de Begin/End actualmente implementado por el System.Net.Sockets.Socket clase requiere un System.IAsyncResult objeto va a asignar para cada operación de socket asincrónico.The Begin/End design pattern currently implemented by the System.Net.Sockets.Socket class requires a System.IAsyncResult object be allocated for each asynchronous socket operation.

En el nuevo System.Net.Sockets.Socket mejoras, las operaciones se describen mediante reutilizable de socket asincrónico de la clase SocketAsyncEventArgs objetos asignados y mantenidos por la aplicación.In the new System.Net.Sockets.Socket class enhancements, asynchronous socket operations are described by reusable SocketAsyncEventArgs objects allocated and maintained by the application. Las aplicaciones de socket de alto rendimiento saben mejor la cantidad de operaciones de socket superpuestas que se deben mantener.High-performance socket applications know best the amount of overlapped socket operations that must be sustained. La aplicación puede crear tantos objetos SocketAsyncEventArgs como necesite.The application can create as many of the SocketAsyncEventArgs objects that it needs. Por ejemplo, si una aplicación de servidor necesita tener 15 socket Aceptar operaciones pendientes en todo momento para admitir velocidades de conexión de cliente entrantes, puede asignar 15 reutilizables SocketAsyncEventArgs objetos para ese propósito.For example, if a server application needs to have 15 socket accept operations outstanding at all times to support incoming client connection rates, it can allocate 15 reusable SocketAsyncEventArgs objects for that purpose.

El patrón para realizar una operación de socket asincrónico con esta clase consta de los pasos siguientes:The pattern for performing an asynchronous socket operation with this class consists of the following steps:

  1. Asigne un nuevo objeto de contexto SocketAsyncEventArgs u obtenga uno libre de un grupo de aplicaciones.Allocate a new SocketAsyncEventArgs context object, or get a free one from an application pool.

  2. Establezca propiedades en el contexto de objeto a la operación sobre ser realizado (el método de devolución de llamada de finalización, el búfer de datos, el desplazamiento en el búfer y la cantidad máxima de datos que se van a transferir, por ejemplo).Set properties on the context object to the operation about to be performed (the completion callback method, the data buffer, the offset into the buffer, and the maximum amount of data to transfer, for example).

  3. Llame al método de socket adecuado (xxxAsync) para iniciar la operación asincrónica.Call the appropriate socket method (xxxAsync) to initiate the asynchronous operation.

  4. Si el método de socket asincrónico (xxxAsync) devuelve true, en la devolución de llamada, consultar las propiedades de contexto para el estado de finalización.If the asynchronous socket method (xxxAsync) returns true, in the callback, query the context properties for completion status.

  5. Si el método de socket asincrónico (xxxAsync) devuelve false, la operación finalice sincrónicamente.If the asynchronous socket method (xxxAsync) returns false, the operation completed synchronously. Para ver el resultado de la operación se pueden consultar las propiedades de contexto.The context properties may be queried for the operation result.

  6. Vuelva a usar el contexto para otra operación, vuelva a colocarlo en el grupo o descártelo.Reuse the context for another operation, put it back in the pool, or discard it.

La duración del nuevo objeto de contexto de operación de socket asincrónico viene determinada por las referencias por el código de la aplicación y las referencias de E/S asincrónicas.The lifetime of the new asynchronous socket operation context object is determined by references by the application code and asynchronous I/O references. No es necesario que la aplicación conserve una referencia a un objeto de contexto de operación de socket asincrónico una vez que se ha enviado como parámetro a uno de los métodos de operación de socket asincrónico.It is not necessary for the application to retain a reference to an asynchronous socket operation context object after it is submitted as a parameter to one of the asynchronous socket operation methods. La referencia se conserva hasta que se devuelve la devolución de llamada de finalización.It will remain referenced until the completion callback returns. Sin embargo es ventajoso para la aplicación conservar la referencia al contexto para que se puede reutilizar para una operación de socket asincrónico futura.However it is advantageous for the application to retain the reference to the context so that it can be reused for a future asynchronous socket operation.

Constructores

SocketAsyncEventArgs() SocketAsyncEventArgs() SocketAsyncEventArgs() SocketAsyncEventArgs()

Crea una instancia de SocketAsyncEventArgs vacía.Creates an empty SocketAsyncEventArgs instance.

Propiedades

AcceptSocket AcceptSocket AcceptSocket AcceptSocket

Obtiene o establece el socket que se va a usar o el socket creado para aceptar una conexión con un método de socket asincrónico.Gets or sets the socket to use or the socket created for accepting a connection with an asynchronous socket method.

Buffer Buffer Buffer Buffer

Obtiene el búfer de datos que se va a usar con un método de socket asincrónico.Gets the data buffer to use with an asynchronous socket method.

BufferList BufferList BufferList BufferList

Obtiene o establece una matriz de búferes de datos que se va a usar con un método de socket asincrónico.Gets or sets an array of data buffers to use with an asynchronous socket method.

BytesTransferred BytesTransferred BytesTransferred BytesTransferred

Obtiene el número de bytes transferidos en la operación de socket.Gets the number of bytes transferred in the socket operation.

ConnectByNameError ConnectByNameError ConnectByNameError ConnectByNameError

Obtiene la excepción en el caso de un error de conexión cuando se usó DnsEndPoint.Gets the exception in the case of a connection failure when a DnsEndPoint was used.

ConnectSocket ConnectSocket ConnectSocket ConnectSocket

Objeto Socket que se ha creado y conectado después de finalizar correctamente el método ConnectAsync.The created and connected Socket object after successful completion of the ConnectAsync method.

Count Count Count Count

Obtiene la cantidad máxima de datos, en bytes, que se van a enviar o recibir en una operación asincrónica.Gets the maximum amount of data, in bytes, to send or receive in an asynchronous operation.

DisconnectReuseSocket DisconnectReuseSocket DisconnectReuseSocket DisconnectReuseSocket

Obtiene o establece un valor que especifica si el socket se puede reutilizar después una operación de desconexión.Gets or sets a value that specifies if socket can be reused after a disconnect operation.

LastOperation LastOperation LastOperation LastOperation

Obtiene el tipo de operación de socket más reciente realizada con este objeto de contexto.Gets the type of socket operation most recently performed with this context object.

MemoryBuffer MemoryBuffer MemoryBuffer MemoryBuffer
Offset Offset Offset Offset

Obtiene el desplazamiento, en bytes, en el búfer de datos al que hace referencia la propiedad Buffer.Gets the offset, in bytes, into the data buffer referenced by the Buffer property.

ReceiveMessageFromPacketInfo ReceiveMessageFromPacketInfo ReceiveMessageFromPacketInfo ReceiveMessageFromPacketInfo

Obtiene la dirección IP e interfaz de un paquete recibido.Gets the IP address and interface of a received packet.

RemoteEndPoint RemoteEndPoint RemoteEndPoint RemoteEndPoint

Obtiene o establece el extremo IP remoto de una operación asincrónica.Gets or sets the remote IP endpoint for an asynchronous operation.

SendPacketsElements SendPacketsElements SendPacketsElements SendPacketsElements

Obtiene o establece una matriz de búferes que se va a enviar para una operación asincrónica utilizada por el método SendPacketsAsync(SocketAsyncEventArgs).Gets or sets an array of buffers to be sent for an asynchronous operation used by the SendPacketsAsync(SocketAsyncEventArgs) method.

SendPacketsFlags SendPacketsFlags SendPacketsFlags SendPacketsFlags

Obtiene o establece una combinación bit a bit de valores TransmitFileOptions para una operación asincrónica utilizada por el método SendPacketsAsync(SocketAsyncEventArgs).Gets or sets a bitwise combination of TransmitFileOptions values for an asynchronous operation used by the SendPacketsAsync(SocketAsyncEventArgs) method.

SendPacketsSendSize SendPacketsSendSize SendPacketsSendSize SendPacketsSendSize

Obtiene o establece el tamaño, en bytes, del bloque de datos utilizado en la operación de envío.Gets or sets the size, in bytes, of the data block used in the send operation.

SocketClientAccessPolicyProtocol SocketClientAccessPolicyProtocol SocketClientAccessPolicyProtocol SocketClientAccessPolicyProtocol

Obtiene o establece el protocolo que se utiliza para descargar el archivo de directivas de acceso de cliente de socket.Gets or sets the protocol to use to download the socket client access policy file.

SocketError SocketError SocketError SocketError

Obtiene o establece el resultado de la operación de socket asincrónico.Gets or sets the result of the asynchronous socket operation.

SocketFlags SocketFlags SocketFlags SocketFlags

Obtiene los resultados de una operación de socket asincrónico o establece el comportamiento de una operación asincrónica.Gets the results of an asynchronous socket operation or sets the behavior of an asynchronous operation.

UserToken UserToken UserToken UserToken

Obtiene o establece a un objeto de usuario o de aplicación asociado a esta operación de socket asincrónico.Gets or sets a user or application object associated with this asynchronous socket operation.

Métodos

Dispose() Dispose() Dispose() Dispose()

Libera los recursos no administrados utilizados por la instancia de SocketAsyncEventArgs y, de forma opcional, elimina los recursos administrados.Releases the unmanaged resources used by the SocketAsyncEventArgs instance and optionally disposes of the managed resources.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determina si el objeto especificado es igual al objeto actual.Determines whether the specified object is equal to the current object.

(Inherited from Object)
Finalize() Finalize() Finalize() Finalize()

Libera los recursos utilizados por la clase SocketAsyncEventArgs.Frees resources used by the SocketAsyncEventArgs class.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Sirve como la función hash predeterminada.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Obtiene el Type de la instancia actual.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Crea una copia superficial del objeto Object actual.Creates a shallow copy of the current Object.

(Inherited from Object)
OnCompleted(SocketAsyncEventArgs) OnCompleted(SocketAsyncEventArgs) OnCompleted(SocketAsyncEventArgs) OnCompleted(SocketAsyncEventArgs)

Representa un método al que se llama cuando se completa una operación asincrónica.Represents a method that is called when an asynchronous operation completes.

SetBuffer(Byte[], Int32, Int32) SetBuffer(Byte[], Int32, Int32) SetBuffer(Byte[], Int32, Int32) SetBuffer(Byte[], Int32, Int32)

Establece el búfer de datos que se va a usar con un método de socket asincrónico.Sets the data buffer to use with an asynchronous socket method.

SetBuffer(Int32, Int32) SetBuffer(Int32, Int32) SetBuffer(Int32, Int32) SetBuffer(Int32, Int32)

Establece el búfer de datos que se va a usar con un método de socket asincrónico.Sets the data buffer to use with an asynchronous socket method.

SetBuffer(Memory<Byte>) SetBuffer(Memory<Byte>) SetBuffer(Memory<Byte>) SetBuffer(Memory<Byte>)
ToString() ToString() ToString() ToString()

Devuelve una cadena que representa el objeto actual.Returns a string that represents the current object.

(Inherited from Object)

Eventos

Completed Completed Completed Completed

Evento utilizado para completar una operación asincrónica.The event used to complete an asynchronous operation.

Se aplica a

Consulte también: