Implementing and Maintaining Your User Entry Point Table (UEPT)

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** This thread discusses the article: Implementing and Maintaining Your User Entry Point Table (UEPT) **
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Very nice article, with easy to follow samples. But I'm confused by these seemingly contradictory statements:


... the following ... will then cause a resolved system pointer to the user program to become invalid:
* The user program is moved ... by using the Move Object (MOVOBJ) command.


... an object that has been ... moved to the QRPLOBJ library as the result of a create command ... has the system pointer pointing to it unchanged.



Do create commands move objects in a different way than MOVOBJ command?

Brian Johnson

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A MOVOBJ operation does NOT change a program's virtual address

** This thread discusses the article: Implementing and Maintaining Your User Entry Point Table (UEPT) **
Thank you so much Brian! You pointed out a mistake that I'd made in this article. The conclusion, "The MOVOBJ command changes a program's virtual address in SLS (and hence makes a revolved system pointer to it becomes invalid)." was based on some experiments I had made long ago. It seems that I had made some kind of mistake at that time. I have to apologize that I didn't double-check it when I put it into the article.

Via a simple experiment like the following, we can find out that a MOVOBJ operation does NOT change a program's virtual address.
- DMPOBJ LIB_A/SOME_PGM *PGM
- MOVOBJ LIB_A/SOME_PGM *PGM LIB_B
- DMPOBJ LIB_B/SOME_PGM *PGM
- Check the spooled files produced by the DMPOBJ commands and compare the "ADDRESS" values before and after the MOVOBJ operation. (They should be the same.)

Thank you again!

Junlei Li