At 2009.12.03 07:57 concerning "Re: question on STORAGE function - TCB may become non-dispatchable?", John Chase <[email protected]>
>> -----Original Message----- >> From: IBM Mainframe Discussion List [On Behalf Of Neil Duffee >> [snip] >>> The original request was for experiences / advice on using 64-bit >>> storage "directly" in CICS, but CICS doesn't support that (yet). [snip] > You apparently missed "directly" above. > > Please cite the syntax for an application program to obtain storage > above the bar. E C GETMAIN doesn't do it. Nope. I saw the "directly" and admit that nothing the the API manual for E C GetMain mentions it specifically. In fact, FLENGTH = fullword implies 32-bits, no? In addition, the "ptr-ref" definition as a "register" is sufficiently vague about 31 vs 64 bit addresses. I'm relying on what both Release Guides mention (some snippets below). Documentation mis-matches? Perhaps. Anyway, my point was that the assumption might not (still) be invalid. I suspect the best resource (outside of an ETR) for detailed discussion is Cics-L 'cause I'm nowhere near a Cics SysProg by a lonnng shot. ----> misc documentation snippets <----- CICS Transaction Server for z/OS Release Guide Version 3 Release 2 : Chapter 19. Storage management above the 2GB boundary "CICS now provides 64-bit storage, allowing you to use storage above the 2GB boundary (above the bar). This capability removes all size restrictions from inter-program data transfer, and provides a means of exploiting z/OS 64-bit capabilities." How storage is allocated and limited : At system initialization, DSA and EDSA are allocated an amount of guaranteed storage, limited by the DSALIM and EDSALIM parameters. GDSA does not preallocate an amount of guaranteed storage and does not have a CICS upper limit of total storage. The limit for above-the- bar storage is controlled by the MEMLIMIT value assigned to the address space by the operating system. As other services in this address space begin to exploit above the bar storage, CICS uses only what it needs. CICS Transaction Server for z/OS Application Programming Reference Version 3 Release 2 : All C and C++ language programs running under CICS must be link- edited with the attributes, AMODE(31), RMODE(ANY). 64bit registers : The following restriction applies to an assembler language application program that uses 64bit registers to exploit 64bit addressing mode or 64bit binary operations: v CICS does not always preserve the high order words of 64bit registers. You must save them before you invoke a CICS service, and restore them before using the 64bit registers again. v ptr-ref can be replaced by an absolute expression that is an assembler-language language reference to a register. GETMAIN : FLENGTH(data-value) specifies the number of bytes of storage required, in fullword binary format. The maximum length that you can specify is the value of the corresponding DSA limit parameter, either DSALIMIT or EDSALIMIT. [snip] CICS Transaction Server for z/OS Release Guide Version 3 Release 1 : Chapter 18. 64-Bit Addressing Toleration changes "CICS can now provide meaningful information when those tasks, which make use of 64-bit addressing architecture, abend. CICS does not support 64-bit addressing execution, but programs can use storage at addresses which are only available when CICS is running on 64-bit architecture machines. These changes provide an extension to the CICS abend capture mechanisms so that the contents of the full 64-bit general purpose registers is captured." ----------> signature = 6 lines follows <-------------- Neil Duffee, Joe SysProg, U d'Ottawa, Ottawa, Ont, Canada telephone:1 613 562 5800 x4585 fax:1 613 562 5161 mailto:NDuffee of uOttawa.ca http:/ /aix1.uottawa.ca/ ~nduffee "How *do* you plan for something like that?" Guardian Bob, Reboot "For every action, there is an equal and opposite criticism." "Systems Programming: Guilty, until proven innocent" John Norgauer 2004 ---------------------------------------------------------------------- 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
