On Mon, 11 May 2009 07:34:43 -0500 Tom Marchant <[email protected]> wrote:
:>On Sat, 9 May 2009 16:35:58 -0400, Tony Harminc wrote: :> :>>2009/5/8 Joe Reichman wrote: :>> :>>> would anyone know if you have a stroage address to determine its nature :>>> :>>> e.g. CSA SQA etc..... :>>> :>>> would I have to check all of the entries in the LDA ..GDA :>>> :>> :>>.... Keep in mind that in many cases the attributes can change :>>between the time you check, and the time you (or some service or :>>program you call) actually uses the storage. :> :>And Binyamin made a similar comment. :> :>What do you mean by this? If you determine that an address is in CSA, it :>will continue to be a CSA address. More precisely, the virtual address will only be assigned to a CSA request. :> Of course, that location could no longer :>be allocated to the same address space, or indeed any address space. CSA is not really allocated to an address space (with the possible exception of a dynamic load to global where the system will free the storage when the LOADer goes away). :> In :>addition, the location could have been converted to SQA, I suppose, or have :>been used to hold a dynamic LPA module. Is that what you are talking about? Basically, if you check the attributes of a storage location they may change before you can use it. It may be released, its key may change, etc. Should a system routine be passed an address that must be validated in some way to make sure that it is the right - kind - of address the appropriate locks must be taken before the processing to make sure that the use does not change. Only if you take the VSM locks that serialize storage allocation, can you be sure that the storage will not be freed and reallocated while your processing takes place. -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
