WSAOVERLAPPED structure (winsock2.h)
The WSAOVERLAPPED structure provides a communication medium between the initiation of an overlapped I/O operation and its subsequent completion. The WSAOVERLAPPED structure is compatible with the Windows OVERLAPPED structure.
Syntax
typedef struct _WSAOVERLAPPED {
DWORD Internal;
DWORD InternalHigh;
DWORD Offset;
DWORD OffsetHigh;
WSAEVENT hEvent;
} WSAOVERLAPPED, *LPWSAOVERLAPPED;
Members
Internal
Type: ULONG_PTR
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
Type: ULONG_PTR
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. NonIFS providers are free to use this parameter as necessary.
Offset
Type: DWORD
Reserved for use by service providers.
OffsetHigh
Type: DWORD
Reserved for use by service providers.
hEvent
Type: HANDLE
If an overlapped I/O operation is issued without an I/O completion routine (the operation's lpCompletionRoutine parameter is set to null), then this parameter should either contain a valid handle to a WSAEVENT object or be null. If the lpCompletionRoutine parameter of the call is non-null then applications are free to use this parameter as necessary.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Header | winsock2.h |