Socket.LingerState Property

Definition

Namespace:

System.Net.Sockets

Assembly:

System.Net.Sockets.dll

Source:

Socket.cs

Gets or sets a value that specifies whether the Socket will delay closing a socket in an attempt to send all pending data.

public:
 property System::Net::Sockets::LingerOption ^ LingerState { System::Net::Sockets::LingerOption ^ get(); void set(System::Net::Sockets::LingerOption ^ value); };

public System.Net.Sockets.LingerOption? LingerState { get; set; }

member this.LingerState : System.Net.Sockets.LingerOption with get, set

Public Property LingerState As LingerOption

Property Value

LingerOption

A LingerOption that specifies how to linger while closing a socket.

Exceptions

SocketException

An error occurred when attempting to access the socket.

ObjectDisposedException

The Socket has been closed.

Examples

The following code example demonstrates the use of the LingerState property.

static void ConfigureTcpSocket(Socket^ tcpSocket)
{
     
    // Don't allow another socket to bind to this port.
    tcpSocket->ExclusiveAddressUse = true;
     
    // The socket will linger for 10 seconds after
    // Socket.Close is called.
    tcpSocket->LingerState = gcnew LingerOption(true, 10);
     
    // Disable the Nagle Algorithm for this tcp socket.
    tcpSocket->NoDelay = true;
     
    // Set the receive buffer size to 8k
    tcpSocket->ReceiveBufferSize = 8192;
     
    // Set the timeout for synchronous receive methods to
    // 1 second (1000 milliseconds.)
    tcpSocket->ReceiveTimeout = 1000;
     
    // Set the send buffer size to 8k.
    tcpSocket->SendBufferSize = 8192;
     
    // Set the timeout for synchronous send methods
    // to 1 second (1000 milliseconds.)
    tcpSocket->SendTimeout = 1000;
     
    // Set the Time To Live (TTL) to 42 router hops.
    tcpSocket->Ttl = 42;
    Console::WriteLine("Tcp Socket configured:");
    Console::WriteLine("  ExclusiveAddressUse {0}", 
        tcpSocket->ExclusiveAddressUse);
    Console::WriteLine("  LingerState {0}, {1}", 
        tcpSocket->LingerState->Enabled,
        tcpSocket->LingerState->LingerTime);
    Console::WriteLine("  NoDelay {0}",
        tcpSocket->NoDelay);
    Console::WriteLine("  ReceiveBufferSize {0}", 
        tcpSocket->ReceiveBufferSize);
    Console::WriteLine("  ReceiveTimeout {0}",
        tcpSocket->ReceiveTimeout);
    Console::WriteLine("  SendBufferSize {0}",
        tcpSocket->SendBufferSize);
    Console::WriteLine("  SendTimeout {0}",
        tcpSocket->SendTimeout);
    Console::WriteLine("  Ttl {0}",
        tcpSocket->Ttl);
    Console::WriteLine("  IsBound {0}",
        tcpSocket->IsBound);
    Console::WriteLine("");
}

static void ConfigureTcpSocket(Socket tcpSocket)
{
    // Don't allow another socket to bind to this port.
    tcpSocket.ExclusiveAddressUse = true;

    // The socket will linger for 10 seconds after
    // Socket.Close is called.
    tcpSocket.LingerState = new LingerOption (true, 10);

    // Disable the Nagle Algorithm for this tcp socket.
    tcpSocket.NoDelay = true;

    // Set the receive buffer size to 8k
    tcpSocket.ReceiveBufferSize = 8192;

    // Set the timeout for synchronous receive methods to
    // 1 second (1000 milliseconds.)
    tcpSocket.ReceiveTimeout = 1000;

    // Set the send buffer size to 8k.
    tcpSocket.SendBufferSize = 8192;

    // Set the timeout for synchronous send methods
    // to 1 second (1000 milliseconds.)
    tcpSocket.SendTimeout = 1000;

    // Set the Time To Live (TTL) to 42 router hops.
    tcpSocket.Ttl = 42;

    Console.WriteLine("Tcp Socket configured:");

    Console.WriteLine($"  ExclusiveAddressUse {tcpSocket.ExclusiveAddressUse}");

    Console.WriteLine($"  LingerState {tcpSocket.LingerState.Enabled}, {tcpSocket.LingerState.LingerTime}");

    Console.WriteLine($"  NoDelay {tcpSocket.NoDelay}");

    Console.WriteLine($"  ReceiveBufferSize {tcpSocket.ReceiveBufferSize}");

    Console.WriteLine($"  ReceiveTimeout {tcpSocket.ReceiveTimeout}");

    Console.WriteLine($"  SendBufferSize {tcpSocket.SendBufferSize}");

    Console.WriteLine($"  SendTimeout {tcpSocket.SendTimeout}");

    Console.WriteLine($"  Ttl {tcpSocket.Ttl}");

    Console.WriteLine($"  IsBound {tcpSocket.IsBound}");

    Console.WriteLine("");
}

Remarks

The LingerState property changes the way Close method behaves. This property when set modifies the conditions under which the connection can be reset by Winsock. Connection resets can still occur based on the IP protocol behavior.

This property controls the length of time that a connection-oriented connection will remain open after a call to Close when data remains to be sent.

When you call methods to send data to a peer, this data is placed in the outgoing network buffer. This property can be used to ensure that this data is sent to the remote host before the Close method drops the connection.

To enable lingering, create a LingerOption instance containing the desired values, and set the LingerState property to this instance.

The following table describes the behavior of the Close method for the possible values of the Enabled property and the LingerTime property stored in the LingerState property.

LingerState.Enabled	LingerState.LingerTime	Behavior
false (disabled), the default value	The time-out is not applicable, (default).	Attempts to send pending data until the default IP protocol time-out expires.
true (enabled)	A nonzero time-out	Attempts to send pending data until the specified time-out expires, and if the attempt fails, then Winsock resets the connection.
true (enabled)	A zero timeout.	Discards any pending data. For connection-oriented socket (TCP, for example), Winsock resets the connection.

The IP stack computes the default IP protocol time-out period to use based on the round trip time of the connection. In most cases, the time-out computed by the stack is more relevant than one defined by an application. This is the default behavior for a socket when the LingerState property is not set.

When the LingerTime property stored in the LingerState property is set greater than the default IP protocol time-out, the default IP protocol time-out will still apply and override.