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Re: To much memory allocated in _Objects_Extend_information()?
==> Chris Johns writes:
CJ> John Alexandersson wrote:
>> Hi all,
>> I'm sitting here looking at the code in
>> score/src/objectextendinformation.c and I don't quite understand how
>> the size of the memory to allocate is calculated.
CJ> It is complex due to the way it extended the existing design without
CJ> changing any of the existing performance requirements. Specifically
CJ> the id to object lookup time.
>> More precise, it is the last part that I find strange:
>> ((maximum + minimum_index) * sizeof(Objects_Control *))
>> Is it correct behaviour to _add_ minimum_index? Shouldn't it be
>> subtracted instead? (maximum - minimum_index)?
>> If it, in fact, is the correct behaviour, could some one please
>> explain why?
CJ> Have you read the Unlimited.txt file in the score/src directory ?
I have now... :)
...and suddenly it all starts to make sense, kind-of.
(I still need some time to fully digest it, but the overall idea seems
reasonably clear now.)
CJ> I have added the file into the Wiki. You can find here:
CJ> It needs some more formatting which I will get to soon.
>> To me it looks like too much memory is allocated here, but since I
>> haven't quite got a grip of the overall handling of Objects yet, I
>> might very well be wrong.
CJ> If you find something of interest please add it to the Wiki. This is a
CJ> difficult piece of code and any supporting documentation is more than
One more question appeared, though.
In Unlimited.txt it says that this code was originally added to RTEMS
Just to make sure; the implementation hasn't changed in any
significant way since v4.0.0, that makes this text obsolete?
(and thanks to Till as well...)
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