XdbeAllocateBackBufferName - allocates a DBE buffer.
#include <X11/extensions/Xdbe.h>
XdbeBackBuffer XdbeAllocateBackBufferName(
   Display *dpy,
   Window window,
   XdbeSwapAction swap_action)
This function returns a drawable ID used to refer to the back buffer of the
  specified window. The swap_action is a hint to indicate the swap action that
  will likely be used in subsequent calls to XdbeSwapBuffers(). The
  actual swap action used in calls to XdbeSwapBuffers() does not have to
  be the same as the swap_action passed to this function, though clients are
  encouraged to provide accurate information whenever possible.
  - BadAlloc
- BadIDChoice
- BadMatch
- The specified window is not an InputOutput window or its visual does not
      support DBE.
- BadValue
- An invalid swap action was specified.
- BadWindow
- An invalid window was specified.
DBE, XdbeBeginIdiom(), XdbeDeallocateBackBufferName(),
  XdbeEndIdiom(), XdbeFreeVisualInfo(),
  XdbeGetBackBufferAttributes(), XdbeGetVisualInfo(),
  XdbeQueryExtension(), XdbeSwapBuffers().