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#define INCL_VIO
 
USHORT VioSavRedrawUndo(fRelinquish, fTerminate, usReserved)
USHORT fRelinquish;    /* retain/relinquish ownership flag */
USHORT fTerminate;     /* terminate/continue flag          */
USHORT usReserved;     /* reserved, must be zero           */
 
The VioSavRedrawUndo function cancels a request by a process to be notified
when MS OS/2 switches screen groups. A process requests to be notified by
calling the VioSavRedrawWait function. The request forces the calling thread
to wait until a screen switch occurs. VioSavRedrawUndo cancels the request
and allows the thread to continue (or terminates the thread, if requested to
do so).
 
MS OS/2 permits only one process in a screen group to request screen switch
notification. The first process to make a request owns it. Thereafter, other
processes must wait for the owning process to relinquish the request before
being given ownership. To force the process to relinquish ownership of the
request, use the VioSavRedrawUndo function.
 
Only the process that owns the change-mode request can call the
VioSavRedrawUndo function.
 
Parameter    Description
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fRelinquish  Specifies whether a process should retain or relinquish
             ownership of the request. If this parameter is UNDOI_GETOWNER,
             the process relinquishes ownership and is canceled by this
             function. If the parameter is UNDOI_RELEASEOWNER, the process
             retains ownership and can repeat the request without competing
             with other processes.
 
fTerminate   Specifies whether to terminate the thread waiting for the mode
             change. If this parameter is UNDOK_ERRORCODE, the thread
             continues and receives an error value from the
             VioSavRedrawWait function. If the parameter is UNDOK_TERMINATE,
             the thread terminates.
 
usReserved   Specifies a reserved value. This parameter must be zero.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value, which may be one of the following:
 
     ERROR_VIO_FUNCTION_OWNED
     ERROR_VIO_INVALID_PARMS
     ERROR_VIO_NO_SAVE_RESTORE_THD
 
See Also
 
VioCreatePS, VioModeUndo, VioSavRedrawWait
 
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