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Sharing data spaces among problem state programs with PSW key 8 through F z/OS MVS Programming: Extended Addressability Guide SA23-1394-00 |
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One way many problem state programs with PSW key 8 - F can share the data in a data space is by placing the entry for the data space on the PASN-AL and obtaining the ALET. In this way, the programs can pass the ALET to other problem state programs in the address space, allowing them to share the data in the data space. The following example describes a problem state program with PSW
key 8 - F creating a data space and sharing the data in that space
with other programs in the address space. Additionally, the program
assigns ownership of the data space to its job step task. This assignment
allows the data space to be used by other programs even after the
creating program's task terminates. In the example, PGM1 creates
a 10-megabyte data space named SPACE1. It uses the TTOKEN parameter
on DSPSERV to assign ownership to its job step task. Before it issued
the DSPSERV CREATE, however, it had to find out the TTOKEN of its
job step task. To do this, it issued the TCBTOKEN macro.
Unless PGM1 or the job step TCB explicitly deletes the data space, the system deletes the data space when the job step task terminates. Note that when PGM1 issues the ALESERV ADD to add the entry for DS1 to the PASN-AL, the system checks to see if an entry for DS1 already exists on the PASN-AL. If an entry already exists, and a problem state program with PSW key 8 - F added the entry, the system rejects the ALESERV ADD request. However, PGM1 can still access the data space. The system will simply not create a duplicate entry. |
Copyright IBM Corporation 1990, 2014
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