When the application is finished processing the part of the object that is in the window, it eliminates the window by using UNMAP. To process a different part of the object, one not already mapped, the application can use the MAP service again. The SAVE, RESET, MAP, and UNMAP services can be invoked repeatedly as required by the processing requirements of the application.
If you issued multiple MAPs to different STOKENs, use STOKEN with UNMAP to identify the data space or hiperspace you want to unmap.
If you issue UNMAP with RETAIN=NO and there are protected pages in the virtual storage window, the system loses the data in the protected pages and preserves the protection status. If you try to reference the protected pages, the system issues abend X'028'. To access the protected pages again, remove the protection status. Then issue the PGSER RELEASE or DSPSERV RELEASE macro to release all physical paging resources.