This example uses the WinSetMsgMode call to set the a delayed message processing mode for private window class "Generic".

#define INCL_WINWINDOWMGR
#define INCL_WINMESSAGEMGR
#include <OS2.H>
HWND hwnd;
HAB hab;
PFNWP GenericWndProc;
CHAR szClassName[] = "Generic"; /* window class name      */

 if (!WinRegisterClass(hab,   /* anchor-block handle       */
         szClassName,         /* class name                */
         GenericWndProc,      /* window procedure          */
         0L,                  /* window style              */
         0));                 /* amount of reserved memory */
     return (FALSE);

 WinSetMsgMode(hab,
               "Generic",
               SMD_DELAYED);