System.Net.Sockets.SocketAsyncEventArgs Class

Represents an asynchronous socket operation.

See Also: SocketAsyncEventArgs Members


public class SocketAsyncEventArgs : EventArgs, IDisposable


The System.Net.Sockets.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. This class was specifically designed for network server applications that require high performance. An application can use the enhanced asynchronous pattern exclusively or only in targeted hot areas (for example, when receiving large amounts of data).

The main feature of these enhancements is the avoidance of the repeated allocation and synchronization of objects during high-volume asynchronous socket I/O. The Begin/End design pattern currently implemented by the System.Net.Sockets.Socket class requires a IAsyncResult object be allocated for each asynchronous socket operation.

In the new System.Net.Sockets.Socket class enhancements, asynchronous socket operations are described by reusable System.Net.Sockets.SocketAsyncEventArgs objects allocated and maintained by the application. High-performance socket applications know best the amount of overlapped socket operations that must be sustained. The application can create as many of the System.Net.Sockets.SocketAsyncEventArgs objects that it needs. 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 System.Net.Sockets.SocketAsyncEventArgs objects for that purpose.

The pattern for performing an asynchronous socket operation with this class consists of the following steps:

[The 'ordered' type of list has not been implemented in the ECMA stylesheet.]

The lifetime of the new asynchronous socket operation context object is determined by references by the application code and asynchronous I/O references. 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. It will remain referenced until the completion callback returns. 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.


Namespace: System.Net.Sockets
Assembly: System (in System.dll)
Assembly Versions:,