Memory management issue (making a game)

Programming Questions

jaewoong.h

Memory management issue (making a game)

in Programming Questions • 8 months ago

HI.

For days, I've been trying to make a not-that-very-simple game.

I started with making some basic interfaces and positioning them without actual function.

It had been so far so good until I noticed that the program takes too much memory, over 600MB often.

To compare, I played Braid, which never exceeded 300MB of memory all the time.

Originally, I coded the program to load up all data at the beginning and never throw them away.

Since I thought this had been a problem, I modified the program to load and throw away data according to the in-game phase.

Say, there are two phases for the game: MENU and WORLD.

In modified code, all needed data for MENU are loaded just before executing MENU.

If you wish to go to WORLD phase, data for MENU are nullified and data for WORLD are loaded before executing WORLD.

Changing phase from WORLD to MENU makes the same process in reverse.

However, it seems like that nullifying variables and objects is never working in terms of memory problem.

The memory never be freed up, while loading data always increases memory usage.

What this means is that if you repeat to go to MENU and WORLD on and on, memory usage just soars, which make the program crash or the whole system restart in the end.

I googled the problem and found that there's something called garbage collector.

I tried to manually call it("System.gc()") knowing that it is not a good idea for most times.

Frustratingly, this didn't seem to work also.

I wonder what is the problem and how can I fix this.

I just cannot concentrate on making the game further because without having the problem solved, doing more would only worsen the problem.

Note that I'm not familiar with any other language including native java, and never have dealt with memory problem so far, which means I'm nearly ignorant about these memory things.

The entire code can be downloaded through the link below:

https://github.com/jaewoongh/HeroManager.git

THANK YOU IN ADVANCE!

Just do not doom me and the project with skeptic view please.

Replies(13)

PhiLho

Re: Memory management issue (making a game)

8 months ago

I don't have the time to analyze in detail your code, but just in case it applies to your problem, there is an issue with image() when used with many different images: it caches each image it draws (keep them in memory), for better performance, letting the garbage collector to empty the cache if needed.
There is a bug in 2.0b7 (at least) where images are never collected.
If that's your problem, you can remove manually the images from the cache after each drawing (using a dispose() call, if you search the forum).
If your sketch is compatible with 1.5.1, you can try and run it with this version, to see if there is the same memory issue. If not, it might be this problem.

jaewoong.h

Re: Re: Memory management issue (making a game)

8 months ago

Thanks a ton PhiLho!

Indeed, there is no problem when I run the code in Processing 1.5.1.

Never exceeds 200MB with P2D, and barely exceeds 300MB with OPENGL all the time!

So I think I have two choices ahead.

1) Keep stick to the 2.0b7 using disposable image class,

2) Just use 1.5.1.

I'd really want to choose option 1 though, because I might find some way of using native java image class, which might give me some more advantages of dealing with lots of images.

I dug the forum to search some hints about dispose() you mentioned, but I couldn't get what I wanted.

I don't get it. PImage just do not accept .dispose() or .kill() things.

Instead, I found some ' crazy fast image load' thing and it looks great.

It's flushable! even though it's more like "if you do not flush, memory leak occurs."

The only problem of this craziness is that the code never works.

Maybe I should dig more for the most desirable solution.

Or should I just use 1.5.1 version?

At any rate,

Thank you so much PhiLho!

PhiLho

Re: Memory management issue (making a game)

8 months ago

Sorry, it was not dispose(), but removeCache().
Found back the related bug: https://github.com/processing/processing/issues/1391
It shows the workaround.

jaewoong.h

Re: Re: Memory management issue (making a game)

8 months ago

THANK YOU PhiLho!

I've had quite a trouble with java this time after I had decided to just use Processing 1.5.1 version.

You are such a silver lining indeed!

Having Processing 1.5.1 that never runs with up to date java, I think I'm obliged to stick to the 2.0b7 version.

Just one more to clarify:

I don't know what the g is, but at any rate, I am supposed to write the g.removeCache(PImage) every after using image() method, right?

jaewoong.h

Re: Re: Memory management issue (making a game)

8 months ago

Umm..

I've tried to add g.removeCache(PImage) to every end of the loop for every PImages used, but things never got better.

Your short leak-and-workaround code demonstrates beautifully about the memory problem of PImage, but I don't understand why this is not working on my code.

I've noticed that the memory usage also increased drastically(about few dozens of megabytes) when displaying - not creating - custom made Menu class which never uses PImage.

Maybe the problem is not solely on PImage thing.

And again, the code had run without any memory problem on Processing 1.5.1 yesterday, until I installed newest JDK.

GoToLoop

Re: Memory management issue (making a game)

8 months ago

Having Processing 1.5.1 that never runs with up to date java, I think I'm obliged to stick to the 2.0b7 version.

Processing's version has nothing to do w/ Java.
You can perfectly run Pv1.5.1 on Java SE JDK 7 (64-bit)!

jaewoong.h

Re: Re: Memory management issue (making a game)

8 months ago

Really?

I'm confused once again. What is my problem then?

Just after installing Oracle's newest JDK 1.7.something yesterday, Processing 1.5.1 never works.

It says "Could not run the sketch" whatever code I try running. Really. Even the simplest ones.

And in the console is like:

[0] "Error: This Java instance does not support a 32-bit JVM."

[1] "Please install the desired version."

Using startup command:

{command=command=java -d32 -Xrunjdwp:transport=dt_socket,address=127.0.0.1:8978,suspend=y -Xms64m -Xmx2048m -Xdock:name=twenty_six -Djava.library.path=:/Applications/Processing151.app/Contents/Resources/Java:/System/Library/PrivateFrameworks/JavaApplicationLauncher.framework/Resources:.:/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java -cp /var/folders/g8/zgygs9jx6sj0fc742vtlx_6h0000gn/T/twenty_six7319478816908529925temp:/Applications/Processing151.app/Contents/Resources/Java/pde.jar:/Applications/Processing151.app/Contents/Resources/Java/core.jar:/Applications/Processing151.app/Contents/Resources/Java/ant.jar:/Applications/Processing151.app/Contents/Resources/Java/ant-launcher.jar:/Applications/Processing151.app/Contents/Resources/Java/antlr.jar:/Applications/Processing151.app/Contents/Resources/Java/ecj.jar:/Applications/Processing151.app/Contents/Resources/Java/jna.jar:/Applications/Processing151.app/Contents/Resources/Java/quaqua.jar -ea processing.core.PApplet "--editor-location=390,100" --external --display=1 --sketch-path=/Users/Jaewoong/Documents/Processing/26/twenty_six twenty_six , quote=quote=", address=address=127.0.0.1:8978}

I'm using Mac OS 10.8.2 a.k.a. mountain lion.

I've been so confused and frustrated since yesterday.

Can you please help me this out?

GoToLoop

Re: Memory management issue (making a game)

8 months ago

Oh, a Mac!
I've tested P 1.5.1 w/ Java SE JDK 7 (64 bit) on a laptop w/ Win7 OS.

I guess it's Apple's fault in this particular Java case.
I've heard about somewhere that Apple provided its own Java install some years ago.
Rather than letting users installing Java from Sun/Oracle's regular package.

Now that Apple abandoned both Java & Flash, its users now have to deal w/ this issue.
But unfortunately, it can conflict w/ MacOS's ancient built-in Java!

Well, that's what I think the problem lies!

jaewoong.h

Re: Re: Memory management issue (making a game)

8 months ago

Indeed!

I almost spent my whole day finding the way to deal with this problem only to get nothing.

It's really a serious problem for the folks like me who basically ignorant about the entire java things.

I'm planning to just re-install my OS and Processing.

I'll post here once again if I get any better of this.

Thank you anyway GoToLoop!

jaewoong.h

Re: Memory management issue (making a game)

8 months ago

Okay, I finally managed to solve my problems.

First thing: about memory leakage

Problem

- Processing 2.0b7 has a bug regarding not collecting garbage

- It is related with PImage somehow

Solution

- PhiLho showed me a workaround solution ( https://github.com/processing/processing/issues/1391 )

- But I'd like to just use Processing 1.5.1 since I found myself not competent to go through the problem

Second thing: "Could not run the sketch" problem on Processing 1.5.1 with JDK 1.7 installed

Problem

- Installing Oracle's latest JDK can kill your Processing 1.5.1 on Mac(mountain lion)

Solution

- Processing 2.0b7 works fine

- If you really need to use Processing 1.5.1, I think removing JDK 1.7 would be a solution

How?

- Delete folder "jdk1.7.0_xx.jdk" at "/Library/Java/JavaVirtualMachines"

- I just happen to do this. I am not 100% sure that this is a safe and proper solution.

- But believe me, I've done lots of so-called solution things and never succeeded

Oh, finally..

Now I can concentrate on coding my game again.

I really appreciate your help and advices!

GoToLoop

Re: Memory management issue (making a game)

8 months ago

[0] "Error: This Java instance does not support a 32-bit JVM."

Just 1 question:
That JDK 7 was 32 or 64 bits?

It's just that the 1st error sentence is saying that somehow
it doesn't support 32-bit JVMs ( Java Virtual Machine)???

Another thing:
To force Processing v1.5.1 to use the installed JDK from the OS,
you have to rename or delete the / java folder which comes w/ Processing's folder!

What perhaps woulda happened is that:
Processing compiles your program using its internal old 32-bit Java 6.
But when it tries to actually run it, the compiled program fails to run under OS's 64-bit Java 7!

jaewoong.h

Re: Re: Memory management issue (making a game)

8 months ago

http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

JDK for Mac OS X provides only one option of 64-bit version.

And I haven't deleted the "java" folder inside the Processing app package.

Since I don't understands those Terminal commands, I have no idea what really happend.

But as you see, "java" inside the Processing app was also shown in the command.

Like:

Djava.library.path=:/Applications/Processing151.app/Contents/Resources/Java:/System/Library/PrivateFrameworks/JavaApplicationLauncher.framework/Resources:.:/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java

or,

launcher.jar:/Applications/Processing151.app/Contents/Resources/Java/antlr.jar:/Applications/Processing151.app/Contents/Resources/Java/ecj.jar:/Applications/Processing151.app/Contents/Resources/Java/jna.jar:/Applications/Processing151.app/Contents/Resources/Java/quaqua.jar

Well,

I don't know what all this means,

but your logic seems probable!

GoToLoop

Re: Memory management issue (making a game)

8 months ago

Well, erasing the Processing's java/ folder is what I did in my own 32-bit WinXP desktop,
and also 64-bit Win7 laptop.

Doing so forced Processing's 1.5.1 to use the Java installed in my OSes, rather than its built-in one!

Just do not do that in most recent Processing versions.
Those ones really expect to find the /java folder!

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