Path: utzoo!attcan!uunet!munnari.oz.au!goanna!ajk
From: ajk@goanna.cs.rmit.oz.au (Alan Kent)
Newsgroups: comp.sys.encore
Subject: share_malloc under UMAX V
Message-ID: <3389@goanna.cs.rmit.oz.au>
Date: 9 Jul 90 05:35:39 GMT
Organization: Comp Sci, RMIT, Melbourne, Australia
Lines: 35

I give up. I am trying to use the share_malloc_init(), share_malloc(),
spin_create() and semaphore_create() functions to set everything
up for a parallel index rebuild program (for a research database
system).  My problem is that I calculate the total amount of memory
that I will need and pass this to share_malloc_init(), but
share_malloc() fails near the end of all the allocation code. I
assume it is running out of shared memory to allocate. I am positive
there are no array overflows or that sort of thing - I am simply
doing a series of share_malloc() calls.

For every share_malloc() call, I allocate an additional 16 bytes
for any structures share_malloc() may need internally. I even add an
extra 10k on at the end. But this still does not work reliably
(sometimes it does, sometimes it doesn't). I do not like the solution
of simply adding another 10k again as it might fix the problem for
now, but at some time in the future it will still fail again.

So, can anyone tell me how to calculate the number to pass to
share_malloc_init() given that you know the number of calls to
share_malloc() and the exact amount that needs to be allocated for
each call?

Any help would be much appreciated.

Ps: the code works perfectly when the mallocs suceed. I dont really want
to have to rewrite several thousand lines of code to switch over to the
threads package (not that I know anything about the threads package).

-------------------------------------------------------------------------------
Dr. Alan Kent,                    ACSNET: ajk@goanna.cs.rmit.OZ
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