Subj : Re: Is rhino's Codegen.generateCode() method thread safe?
To   : tomi@osaka.niss.co.jp
From : Igor Bukanov <igor@icesoft.com>
Date : Wed Mar 12 2003 02:38 pm

Tomita Tomohiro wrote:
> Hi,
> I have some question about rhino.

What version of Rhino do you use and what is your JVM name/version/platform?

> 
> I'm using rhino in multi thread.
> Is the Codegen.generateCode() method thread safe?

Codegen is not thread safe but its usage is safe since its instances are 
accessed only by the single thread that creates them.

> #I have no time to trace or debug rhino source,so I ask this ML :-)
> 
> in my enviroment(j9VM) the error occures very often as follows:
> java.lang.StringIndexOutOfBoundsException
> Stack trace:
>    java/lang/Throwable.<init>()V
>    java/lang/String.charAt(I)C
>    org/mozilla/classfile/ClassFileWriter.sizeOfParameters(Ljava/lang/String;)I
>    org/mozilla/classfile/ClassFileWriter.add(BLjava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V
>    org/mozilla/javascript/optimizer/Codegen.addStaticInvoke(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V
>    org/mozilla/javascript/optimizer/Codegen.visitRegularCall(Lorg/mozilla/javascript/Node;ILorg/mozilla/javascript/Node;Z)V
>    org/mozilla/javascript/optimizer/Codegen.visitCall(Lorg/mozilla/javascript/Node;ILorg/mozilla/javascript/Node;)V
>    org/mozilla/javascript/optimizer/Codegen.generateCodeFromNode(Lorg/mozilla/javascript/Node;Lorg/mozilla/javascript/Node;II)V
>    org/mozilla/javascript/optimizer/Codegen.generateCodeFromNode(Lorg/mozilla/javascript/Node;Lorg/mozilla/javascript/Node;II)V
>    org/mozilla/javascript/optimizer/Codegen.generateCodeFromNode(Lorg/mozilla/javascript/Node;Lorg/mozilla/javascript/Node;II)V
>    org/mozilla/javascript/optimizer/Codegen.generateCode(Lorg/mozilla/javascript/Node;Ljava/util/Vector;Ljava/util/Vector;Lorg/mozilla/javascript/ClassNameHelper;)Ljava/lang/String;
>    org/mozilla/javascript/optimizer/Codegen.compile(Lorg/mozilla/javascript/Context;Lorg/mozilla/javascript/Scriptable;Lorg/mozilla/javascript/Node;Ljava/lang/Object;Lorg/mozilla/javascript/SecuritySupport;Lorg/mozilla/javascript/ClassNameHelper;)Ljava/lang/Object;
>    org/mozilla/javascript/Context.compile(Lorg/mozilla/javascript/Scriptable;Lorg/mozilla/javascript/TokenStream;Ljava/lang/Object;Ljava/io/Reader;Z)Ljava/lang/Object;
>    org/mozilla/javascript/Context.compile(Lorg/mozilla/javascript/Scriptable;Ljava/io/Reader;Ljava/lang/String;ILjava/lang/Object;Z)Ljava/lang/Object;
>    org/mozilla/javascript/Context.compileReader(Lorg/mozilla/javascript/Scriptable;Ljava/io/Reader;Ljava/lang/String;ILjava/lang/Object;)Lorg/mozilla/javascript/Script;
>    tomi.run()V
>    java/lang/Thread.run()V
> 
> if compiling JavaScript in single thread, then it works good.

The fact that org/mozilla/classfile/ClassFileWriter.sizeOfParameters() 
accesses a character outside string is a bug in sizeOfParameters since 
the function is supposed to check for bad method signatures and throw 
exlicit exception about it. But its usage in 
org/mozilla/javascript/optimizer/Codegen.java is correct, so I suspect a 
bug in JVM.

Regards, Igor

.