Releasing hiperspace storage
Your program needs to release storage when it used a hiperspace for one purpose and wants to reuse it for another purpose, or when your program is finished using the area. To release the virtual storage of a hiperspace, use the DSPSERV RELEASE macro. (Hiperspace™ release is similar to a PGSER RELEASE for an address space.) Specify the STOKEN to identify the hiperspace and the START and BLOCKS parameters to identify the beginning and the length of the area you need to release.
Releasing storage in a hiperspace requires that a program have
the following authority:
- The program must be the owner of the hiperspace.
- The program's PSW key must equal the storage key of the hiperspace the system is to release. Otherwise, the system abends the caller.
After the release, a released page does not occupy expanded (or auxiliary) storage until your program references it again. When you again reference a page you have released, the page contains hexadecimal zeroes.
Use DSPSERV RELEASE instead of the MVCL instruction to clear 4K
byte blocks of storage to zeroes because:
- DSPSERV RELEASE is faster than MVCL for very large areas.
- Pages released through DSPSERV RELEASE do not occupy space in expanded or auxiliary storage.