Shielding Success Rates Mystery

Hi mate.

I was in the mood to check XanderCat 12.2 on my system and maybe it can help you to detect some uncertainties.

Mac OS X 10.6.8

java version "1.6.0_37"
Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-10M3909)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode)

Robocode version: 1.7.4.4
CPU constant: 5426594 nanoseconds

Result vs Virus (png) Last Round Log vs Virus (png) Round start log vs Virus (log)

I started a couple of runs and it looks like almost 50% failed because of massive skipped turns if the round starts. This happens if the client runs on low speed and as well on full speed. If I put the client on debug=on, everything works fine and XanderCat win all rounds like expected. Because of the skipped turns XanderCat misses quite a few bullet catches and decides to move with a different movement - from that point he is almost ever doomed to loose some rounds. I hope it helps a little.

BulletShieldTest 1.0 worked so far very good on my system. He is lost against all 'sloppy' guns (HawkOfFire,SpinBot..) but against well coded targeting he has a quite impressive performance. Of course, he has still some minor flaws but i guess that is not unusual for a test version.

All in all i would say there is no difference in how the JVMs handle intersection but there may be a difference how they handle garbage collection and therefor have a different skipped turn behavior.

Man, I wished I had more time these days :( - take care

Thank you, Wompi. That is very helpful. From the round log, looks like there are occasional skipped turns (most likely due to the wave surfing drive and guess factor guns, but these sit idle when bullet shielding is active, and bullet shielding is much less processing intensive). However, the first round where most things are initialized is the worst.

So it's probable the problem isn't with the JVM doing the shielding calculations but rather how much time each system is allowing and how long it takes my initialization code to run (which I can work on, but it may also be true that different JVMs take different amounts of time for different types of initialization).

Looking at the info provided by the run time loggers, the averages between my system and yours aren't all that different, but the peaks shown on yours are an order of 5x what they are on mine. The radar peaks are even worse, which is weird. A typical greatest peak for my radar on my system is 0.25 trialing down to less than 0.1 by the 3rd peak, whereas on your system they start at 9.9 and are still above 0.8 by the 5th peak. (note: peaks are over the entire however-many round battle, as are the averages)

Both your system and Voidious' system are using the Server VM, and that makes me suspicious. I need to try out a Server VM and see what happens.

It should be noted that if this is the problem for Voidious, DivineOmega, and perhaps others, it is affecting overall performance (in the first round at least) and not just on the bullet shielding. If I can find a way to fix it, overall rumble performance could improve some.