Re: embedded and threaded - in java

On Friday, May 23, 2003, at 12:27  pm, Meg Crocker wrote:

> Hi!
>
>     Has anyone embedded perl in java with threads or multiple
> interpreters?
>

Hi,

Sorry for not responding earlier, I have been on my honeymoon and now 
just arrived for YAPC.

I would first of all suggest you try a maintperl snapshot to get all 
the fixes that 5.8.1 will have.

>     I'm trying to build something based on JPerl
> (http://search.cpan.org/author/SBALA/jp_beta_1/) and I think I'm
> running up against my clue barrier - I'm seeing segfaults and panics
> ("panic: top_env") when I try to run stuff, even with a single thread.
>
>     I sprinkled in PERL_SET_CONTEXTs liberally, pretty much at the
> beginning of any jperl function that uses a perl_ function or a perl
> macro...
>

You need to make sure that only one thread is using one perl context at 
the same time, other bad stuff will happen. I suggest you look at the 
mod_perl 2 threaded mpm project to see how they are doing.

>     Tips would be terribly appreciated.  I'm using perl5.8.0 and java
> 1.3 (hotspot jvm) on solaris 8.  Here's a stupid question to get you
> started: My java is linked against libthread; perl seems to prefer
> libpthread.  Do I need to make perl use libthread?  It looks like
> libpthread uses libthread itself...
>

I have no idea actually, I am not a solaris expert.

> Also:
>     - Do I need to "use threads" or any thread functions in my perl?
>     I haven't yet - I've started with a single interp called from a
>     single java thread.  But I read in one older message that perl
>     takes shortcuts if it doesn't think the thread stuff will actually
>     be used?
>

No you don't, get the simple stuff working first.

>     - Would all this be simpler with a mere multiplicity perl instead
>       of a multiplicity-ithreads perl?  I think I'd still need to be
>       able to call each interpreter from multiple threads to get the
>       performance characteristics I'm looking for.
>

No, because a non ithreaded perl will not be able to run more than one 
perl interpreter at the same time.

> Thanks.  :(
> Meg Crocker
>

Arthur