[Gc] Problem with finalizers
scholz at scriptolutions.com
Wed May 2 18:08:40 PDT 2007
Thursday, May 3, 2007, 6:26:15 AM, you wrote:
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BH> From: "Bruce Hoult" <bruce at hoult.org>
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BH> To: "Lothar Scholz" <scholz at scriptolutions.com>
BH> Subject: Re: [Gc] Problem with finalizers
BH> Cc: gc at napali.hpl.hp.com
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BH> On 5/3/07, Lothar Scholz <scholz at scriptolutions.com> wrote:
>> i have written a test program that works fine. It just allocates 400
>> objectes in a loop 200 of them having finalizers. This loop is
>> repeated many times. No references to create objects are held after
>> the loop.
>> Now the strange behaviour:
>> Without finalizers its fast, but with finalizers the whole app stops
>> many times in the gc (as i guess) for seconds. Instead of 200 ms it
>> takes about 22 sec to finish. The finalizer function is empty and
>> there is no CPU load during the stops.
BH> I've got $100 says you're swapping.
Good advise for you: Be more carefull with your money :-)
The program just takes 5 MB on a 2 GB (Core2Duo) system. CPU usage is
below 5% with a peak at 9%.
I wouldn't be surprised if somethings happen or the whole thing
deadlocks. But it just stops for a few seconds and then continues.
And it's just the one i uncomment the
line it all works fine.
BH> It takes memory to record the fact than an object has a finalizer.
BH> Having a finalizer prevents objects from being collected in the first
BH> GC after they become unreferenced, and they have to stay until the 2nd
Maybe Hans can tell me if it is okay to call GC_free from inside the
finalizer to tell the GC that it is not referenced again.
I also tried it with 'GC_finalize_on_demand' set to 0 and 1. No
difference in behaviour.
Lothar Scholz mailto:scholz at scriptolutions.com
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