Notifies a graphics-mode application when it must restore its video mode, state, and modified display-adapter registers. The return from this call provides the notification.

#define INCL_VIO
#include <os2.h>

ULONG     RequestType;  /*  Request type. */
PULONG    NotifyType;   /*  Notify type. */
ULONG     Reserved;     /*  Reserved.  Must be 0. */
APIRET    rc;           /*  Return code. */

rc = VioModeWait(RequestType, NotifyType,
       Reserved);