[Gnash-dev] Memory use

[strk]

Hi all,
as some of you may have been noticing I've spent some time 
on analyzing high memory use of Gnash during execution of potlatch.
Full story here: http://savannah.gnu.org/bugs/index.php?28009

The problem is many AS objects are allocated in a loop
(around 3500 iterations) and are only destroyed at the
very end of actions execution.

The amount of memory allocated by the end of action execution
is over 1Gb. The GC run properly drops most of these objects
(altought memory isn't released to the system, despite GLIBCXX_FORCE_NEW).

Now, beside the release of resources to the system, which at this point
is secondary, what's interesting is that running the GC earlier can
keep the memory much much lower.
For example, with the testcase attached to the bug we can from
723mb to 260mb.

The problem is that running the GC is very expensive as we need
to scan all reachable objects.

Currently the only heuristic to avoid GC runs is based on the number
of collectable resources allocated since last run, which defaults to 50
and can be changed by exporting the GNASH_GC_TRIGGER_THRESHOLD environment
variable. 

Can anyone think of other strategies to decide *when* to run the GC ?


--strk; 

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