jython-dev

[Jython-dev] Re: tojava() failing

[<bc...@wo...>]

>> That is because the BytecodeLoaders happens to search the
>> SyspathJavaLoader before searching the referent class loaders. It's a
>> bug.
>
>No, I would'nt say it is a bug. The problem is that 
>the guilty class is loadable
>both by MultiClassLoader and probably from classpath.
>In those cases it is better if the user dis-entangle that, because
>, yes we can with good-will, change the order, but the only safe
>solution is to avoid that at all.

Right.

>Without knowing the specific up to the details, I will not
>change the actual order.

Ok, maybe simply reversing the order is too naive, but I can't imagine a
situation where it make sense to try and load a superclass by the
SyspathJavaLoader when we in BytecodeLoader.makeClass() know that the
superclass was initially loaded from one of the referent loaders. 

regards,
finn

Re: [Jython-dev] Re: tojava() failing

[Samuele P. <ped...@bl...>]

> 
> >> That is because the BytecodeLoaders happens to search the
> >> SyspathJavaLoader before searching the referent class loaders. It's a
> >> bug.
> >
> >No, I would'nt say it is a bug. The problem is that 
> >the guilty class is loadable
> >both by MultiClassLoader and probably from classpath.
> >In those cases it is better if the user dis-entangle that, because
> >, yes we can with good-will, change the order, but the only safe
> >solution is to avoid that at all.
> 
> Right.
> 
> >Without knowing the specific up to the details, I will not
> >change the actual order.
> 
> Ok, maybe simply reversing the order is too naive, but I can't imagine a
> situation where it make sense to try and load a superclass by the
> SyspathJavaLoader when we in BytecodeLoader.makeClass() know that the
> superclass was initially loaded from one of the referent loaders. 

Before saying anything more, I would like to know what is happening in this
case:
- which classloader is loading the classes from jython.jar
- which classloader is loading the classes using PythonInterpreter
- why import loads the right class but BytecodeLoader not ???
- the content of sys.path and CLASSPATH 

Samuele.


 

Re: [Jython-dev] Re: tojava() failing

[<bc...@wo...>]

>Before saying anything more, I would like to know what is happening in this
>case:

Take a look at bugtests/test338 which I hope illustrate the issue.

>- which classloader is loading the classes from jython.jar

The sun.misc.Launcher$AppClassLoader.

>- which classloader is loading the classes using PythonInterpreter

The custom classloader (Multi).

>- why import loads the right class but BytecodeLoader not ???

Ahh yes. The superclass is not imported by python but loaded by the
Multi loader and inserted manually into the interpreter namespace.

If the superclass is imported imto the script, the example will still
fail, but that is a feature <wink>.

>- the content of sys.path and CLASSPATH 

In the test338 example the guilty superclass can be found by the
CLASSPATH, in the sys.path and by the custom classloader. There is amble
opportunity to load the guilty superclass by the wrong classloader here.

regards,
finn