WSACOMPLETION structure (winsock2.h)

The WSACOMPLETION structure specifies completion notification settings for I/O control calls made to a registered namespace.

Syntax

typedef struct _WSACOMPLETION {
  WSACOMPLETIONTYPE Type;
  union {
    struct {
      HWND   hWnd;
      UINT   uMsg;
      WPARAM context;
    } WindowMessage;
    struct {
      LPWSAOVERLAPPED lpOverlapped;
    } Event;
    struct {
      LPWSAOVERLAPPED                    lpOverlapped;
      LPWSAOVERLAPPED_COMPLETION_ROUTINE lpfnCompletionProc;
    } Apc;
    struct {
      LPWSAOVERLAPPED lpOverlapped;
      HANDLE          hPort;
      ULONG_PTR       Key;
    } Port;
  } Parameters;
} WSACOMPLETION, *PWSACOMPLETION, *LPWSACOMPLETION;

Members

Type

Type: WSACOMPLETIONTYPE

The type of completion notification required. See Remarks.

Parameters

The parameters required to complete the callback. The structures within the Parameters union specify information required for completing the callback of each given type. For example, the WindowMessage structure must be filled when Type is set to NSP_NOTIFY_HWND.

Parameters.WindowMessage

Parameters.WindowMessage.hWnd

Type: HWND Windows handle.

Parameters.WindowMessage.uMsg

Type: UINT Message handle.

Parameters.WindowMessage.context

Type: WPARAM Context of the message or handle.

Parameters.Event

Parameters.Event.lpOverlapped

Type: LPWSAOVERLAPPED A pointer to a WSAOVERLAPPED structure.

Parameters.Apc

Parameters.Apc.lpOverlapped

Type: LPWSAOVERLAPPED A pointer to a WSAOVERLAPPED structure.

Parameters.Apc.lpfnCompletionProc

Type: _In_opt_ LPWSAOVERLAPPED_COMPLETION_ROUTINE

A pointer to an application-provided completion routine.

Parameters.Port

Parameters.Port.lpOverlapped

Type: LPWSAOVERLAPPED A pointer to a WSAOVERLAPPED structure.

Parameters.Port.hPort

Type: HANDLE A handle to the port.

Parameters.Port.Key

Type: ULONG_PTR A pointer to the key.

Remarks

The WSACOMPLETION structure enables callbacks to be provided in any of the following formats, based on the value provided in Type:

For a blocking function, set the WSACOMPLETION structure to null.

Requirements

See also

WSANSPIoctl