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Creating and using data spaces z/OS MVS Programming: Extended Addressability Guide SA23-1394-00 |
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A data space is a range of up to two gigabytes of contiguous virtual storage addresses that a program can directly manipulate through assembler instructions. Unlike an address space, a data space contains only data; it does not contain common areas or system data or programs. Program code does not execute in a data space, although a program can reside in a data space as nonexecutable code. The DSPSERV macro with the TYPE=BASIC parameter (the default) manages
data spaces. Use this macro to:
A program's ability to create, delete, and access data spaces depends on whether it is a problem state program with PSW key 8 - F, a supervisor state program, or a PSW key 0-7 program. All programs can create, access, and delete the data spaces they own or created, and can share their data spaces with other programs running in the same address space. In addition, supervisor state or PSW key 0-7 programs can share their data spaces with programs in other address spaces. Unless otherwise stated, this section describes what the supervisor state or PSW key 0-7 programs can do. Use this section to help you create, use, and delete data spaces.
In addition, four sources of information can help you understand how
to use data spaces:
With the arrival of the 64-bit address space, are there still reasons to create and use data spaces? Even after z/OS® R2, there are still reasons
why you would chose to use a data space. Two reasons are:
There is no need to change any existing programs that create and use data spaces. Data spaces will continue to be supported. |
Copyright IBM Corporation 1990, 2014
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