Re: mochalua heap memory issues?

[Raymond Jacobs <raymondj@...>]

I wanted to follow up with this; as I discovered the issue.

Detailed here:
http://code.google.com/p/mochalua/issues/detail?id=5

It is not mochalua's fault, though with a lack of documentation it is potentially easy to fall into this trap.

luaL_loadstring takes a String type, but only accepts binary data within the string type;
Java has some rather weasily functions when it comes to converting a byte[] to a String.

In my cause it caused 'some' of my bytes to be transcoded based on the current locale;
enough that most of lua chunk would be deserialized; however in one case the int length prefix of a string
constant was changed, resulting in a smaller number; this caused an under-read of the subsequent string
the subsequent int read was the number of lua functions which turned out to be wrong; resulting in a LARGE int value;
this int value is promptly used as the quantity for an array of LuaFunctions; but the large size causes an instant out of memory
error.

Only through inspecting what was going in by attaching the mochalua source; and a lot of time, was I able to figure this out.
Due to the nature of system specific encoding; and the varied nature of input files, it's potential that people could have this issue and not even know about it; as trivial scripts worked fine for me. and the out of memory error didint point to anything being wrong in my bytecode data.

-Raymond

On Thu, Nov 5, 2009 at 10:22 AM, Raymond Jacobs <raymondj@gmail.com> wrote:

Greetings all,

I hope it is alright posting about mochalua here;
I couldn't seem to find a good spot to talk about mochalua elsewhere.

I've recently started using mochalua in my Java 1.6 SE application;
and while I can get small, trivial lua code to run; a larger multi-function script
results in a Java out of heap memory exception.

I've tried to set the xms and xmm VM arguments to up the JVM heap size but nothing seems to be helping.

I am using luaL_loadstring to load the data;

has anyone had similar issues when working with mochalua?

Any information is appreciated,

Thanks,

Raymond Jacobs
Owner,
Ethereal Darkness Interactive
www.edigames.com