PFN_WSK_CLOSE_SOCKET callback function

The WskCloseSocket function closes a socket and frees any associated resources.



NTSTATUS PfnWskCloseSocket(
  PIRP Irp



A pointer to a WSK_SOCKET structure that specifies the socket object for the socket that is being closed.


A pointer to a caller-allocated IRP that the WSK subsystem uses to complete the close operation asynchronously. For more information about using IRPs with WSK functions, see Using IRPs with Winsock Kernel Functions.

Return Value

WskCloseSocket returns one of the following NTSTATUS codes:

Return code Description
The socket was successfully closed. The IRP will be completed with success status.
The WSK subsystem could not close the socket immediately. The WSK subsystem will complete the IRP after it has closed the socket. The status of the close operation will be returned in the IoStatus.Status field of the IRP.
Other status codes
An error occurred. The IRP will be completed with failure status.


Before calling the WskCloseSocket function, a WSK application must ensure that there are no other function calls in progress to any of the socket's functions, including any extension functions, in any of the application's other threads. For example, a WSK application must not call WskCloseSocket on a socket in one thread while the application is calling WskSend on the same socket in another thread. Any in-progress calls to the socket's functions must return control back to the WSK application before it calls WskCloseSocket to close the socket. However, a WSK application can call WskCloseSocket if there are pending IRPs from prior calls to the socket's functions that have not yet completed.

Calling the WskCloseSocket function causes the WSK subsystem to cancel and complete all pending IRPs from prior calls to the socket's functions. The WSK subsystem also ensures that any in-progress event callback functions have returned control back to the WSK subsystem before it closes the socket.

After a WSK application has called WskCloseSocket, it should not make any further calls to any of the socket's functions.

If a WSK application applies a security descriptor to a socket, the cached copy of the security descriptor that is specified in the call to WskSocket, WskSocketConnect, or WskControlSocket is not released when the socket is closed. A WSK application must release the cached copy of the security descriptor by using the WSK_RELEASE_SD client control operation when the security descriptor is no longer needed.

The WSK subsystem deallocates the memory for the socket's socket object, WSK_SOCKET, which was allocated by the WSK subsystem when the socket was created.

For connection-oriented sockets, the WskCloseSocket function always performs an abortive disconnect of the socket unless the socket is already fully disconnected in both directions. To gracefully disconnect a connection-oriented socket from a remote transport address, a WSK application should call the WskDisconnect function.


Windows version Available in Windows Vista and later versions of the Windows operating systems.
Target Platform Universal
Header wsk.h (include Wsk.h)

See Also