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From "William A. Rowe, Jr." <wr...@rowe-clan.net>
Subject RE: cvs commit: httpd-2.0 STATUS
Date Thu, 29 Jul 2004 16:24:53 GMT
At 10:26 AM 7/29/2004, William A. Rowe, Jr. wrote:
>If you changed worker_score, it would still have broken (or if you change
>balancers in the future.)  Agents reviewing the scoreboard are presuming 
>scoreboard_entry *psb can be accessed as psb[0..n] and that -will- be 
>broken with any size/alignment change to the struct.
>
>E.g. [...?]

we have individual element accessors, but older style code presumes it
can loop through the array of individual worker threads/procs.  Adding
another element to worker_score would break the starting offset of the
members psb[1..n].  Although we create the pointer-pointer logic in the
children to avoid this, it's still possible that the code would break some 
modules.

I can't envision a case where any of the scoreboard entries are allocated
outside of our scoreboard.c code.

At 11:01 AM 7/29/2004, Mladen Turk wrote:

> I was afraid you've gonna said that. Those 3rd party... :).

> How about adding extra data to the end of the entire scoreboard withouth
> touching any existing structs or data?
> It will require an extra copy on child_init, but there will be no
> compatibility issues, thought.

You aren't changing worker_score so this isn't an issue.  The patch
already creates (new) a fourth lb_score array.

Bill




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