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Request: Measure CPU time, not wall clock time

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Request: Measure CPU time, not wall clock time

Postby jmcarthur » Tue Feb 23, 2010 7:47 pm

I think most of peoples' problems with timing out are coming from server load. Assuming that lessening the load on the server is impractical, a simple fix would be to impose a CPU time constraint per turn rather than a wall clock time constraint.
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Re: Request: Measure CPU time, not wall clock time

Postby kduleba » Tue Feb 23, 2010 7:57 pm

I would be really surprised if programs were tested on the same set of machines that are running the web server or other load-generating services.
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Re: Request: Measure CPU time, not wall clock time

Postby jmcarthur » Tue Feb 23, 2010 8:01 pm

No, I'm sure they aren't. What I'm not so sure about is how well the server is scheduling the games, cleaning up after them, etc. All I know is that a lot of people are having timeout issues and a lot of people are having issues where their bots are behaving in ways that they would only do if they are getting like 10ms to run sometimes.
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Re: Request: Measure CPU time, not wall clock time

Postby amstan » Tue Feb 23, 2010 8:18 pm

The server playing the games does not run the webserver nor the database.
As for the wall clock vs cpu clock please see other threads for why this is not possible.
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Re: Request: Measure CPU time, not wall clock time

Postby _adept_ » Tue Feb 23, 2010 10:16 pm

OK, but at least you do confirm that there is a real problem with timeouts which (could/would) not be solved?
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Re: Request: Measure CPU time, not wall clock time

Postby amstan » Tue Feb 23, 2010 11:31 pm

The main problem that i noticed going on from the forums is that people are still using cpu time even though wall time matters, so they time out because they might be getting less than 1 second cpu time.
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Re: Request: Measure CPU time, not wall clock time

Postby _adept_ » Tue Feb 23, 2010 11:40 pm

OK. So, i have about 6 different versions of my code that did not use timeouts at all, and use restricted minimax depth instead. All of them competed succesfully untill 19.02. Now all of them timeout instantly.

I have several different versions of code that tries to measure time. They use CPU time, wall time, or both (for good measure). All of them manage NOT to time out ONLY if the cutoff time is set to 0.05 second or even lower.

Well, you could call this "getting less than 1 second of CPU time", I admit. How come this did not happen before the 19.02?
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Re: Request: Measure CPU time, not wall clock time

Postby dutchflyboy » Wed Feb 24, 2010 1:18 pm

Strange, I tell my program to calculate for 900ms, but I've never had a timeout yet.
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Re: Request: Measure CPU time, not wall clock time

Postby Queue29 » Wed Feb 24, 2010 2:06 pm

I think it makes a big difference which language you are using.
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Re: Request: Measure CPU time, not wall clock time

Postby Maxime81 » Thu Feb 25, 2010 1:36 am

I would like to know if the time measurement will change for the final... Because my current bot never timeout but when I activate a handler to avoid the timeout he's acting like he didn't found enough time and go to north ! And this behavior only happens on the server :/. I really don't understand. I'm using C++ and the same code than proposed on another topic... And it's working on my computer...
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