Platform SDK: DirectX

IDirectDrawSurface7::PageUnlock

The IDirectDrawSurface7::PageUnlock method unlocks a system-memory surface, allowing it to be paged out.

HRESULT PageUnlock(
  DWORD dwFlags  
);

Parameters

dwFlags
Currently not used and must be set to 0.

Return Values

If the method succeeds, the return value is DD_OK.

If it fails, the method can return one of the following error values:

DDERR_CANTPAGEUNLOCK
DDERR_INVALIDOBJECT
DDERR_INVALIDPARAMS
DDERR_NOTPAGELOCKED
DDERR_SURFACELOST

Remarks

A lock count is maintained for each surface and is incremented each time that IDirectDrawSurface7::PageLock is called for that surface. The count is decremented when IDirectDrawSurface7::PageUnlock is called. When the count reaches 0, the memory is unlocked, and can then be paged by the operating system.

This method works only on system-memory surfaces; it does not page-unlock a display-memory surface or an emulated primary surface. If an application calls this method on a display-memory surface, this method does nothing except return DD_OK.

This method was not implemented in the IDirectDraw interface.

Requirements

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 98.
  Header: Declared in ddraw.h.

See Also

IDirectDrawSurface7::PageLock