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IDirectDrawSurface7::PageUnlock method (ddraw.h)

  • Article

Unlocks a system-memory surface, which then allows it to be paged out.

Syntax

HRESULT PageUnlock(
  [in] DWORD unnamedParam1
);

Parameters

[in] unnamedParam1

Currently not used and must be set to 0.

Return value

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 PageUnlock is called. When the count reaches 0, the memory is unlocked, and can then be paged by the operating system.

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

IDirectDrawSurface7::PageUnlock was not implemented in the IDirectDraw interface version.

Requirements

Requirement Value
Target Platform Windows
Header ddraw.h
Library Ddraw.lib
DLL Ddraw.dll

See also

IDirectDrawSurface7