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4/8/2010

This structure provides a communication medium between the initiation of an overlapped I/O operation and its subsequent completion.

Note:
With the exception of SIO_ROUTING_INTERFACE_CHANGE and SIO_ADDRESS_LIST_CHANGE, all network drivers running in the kernel and calling into Winsock APIs cannot use overlapped IO. For more information, see WSARecv, WSARecvFrom, WSASend, WSASendTo, and WSAIoctl.

Syntax 

typedef struct _WSAOVERLAPPED {
  DWORD 
Internal;
  DWORD 
InternalHigh;
  DWORD 
Offset;
  DWORD 
OffsetHigh;
  WSAEVENT 
hEvent;
} WSAOVERLAPPED, *LPWSAOVERLAPPED;

Members

Internal

Reserved for internal use. The Internal member is used internally by the entity that implements overlapped I/O. For service providers that create sockets as installable file system (IFS) handles, this parameter is used by the underlying operating system. Other service providers (non-IFS providers) are free to use this parameter as necessary.

InternalHigh

Reserved. Used internally by the entity that implements overlapped I/O. For service providers that create sockets as IFS handles, this parameter is used by the underlying operating system. Non-IFS providers are free to use this parameter as necessary.

Offset

Reserved for use by service providers.

OffsetHigh

Reserved for use by service providers.

hEvent

If an overlapped I/O operation is issued without an I/O completion routine ( lpCompletionRoutineis null), then this parameter should either contain a valid handle to a WSAEVENTobject or be null. If lpCompletionRoutineis non-null then applications are free to use this parameter as necessary.

Requirements

Header winsock2.h
Windows Embedded CE Windows CE .NET 4.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also