public inbox for
 help / color / mirror / Atom feed
From: Andrew Haley <>
Subject: Re: Add a Field to java.lang.Object
Date: Wed, 08 Jun 2011 18:31:00 -0000	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 06/08/2011 06:20 PM, Noah Heusser wrote:

> I'm trying to add an new extra field into java.lang.Object. I need that
> to do some memory synchronization via Network.
> If I just insert the new Field in libjava/java/lang/Object.h (access
> form the Java World is not needed) I get a segmentation fault whenever I
> try to run a Java Software using that Object.h. (It does no matter
> whether I add it to _JvObjectPrefix or java::lang::Object)
> If the JV_HASH_SYNCHRONIZATION Preprocessor Variable is not defined an
> extra Filed sync_info gets inserted in Object.h.
> But everywhere where extra Code is inserted depending on
> JV_HASH_SYNCHRONIZATION it seems to deal with whether or not the Garbage
> Collector needs to scan the Object.
> If I add the Field in libjava/java/lang/ I get a compile
> Error when I compile gcj:
> ../../../../gcc-src/libjava/java/lang/ internal
> compiler error: Segmentation fault
> What extra change is needed after adding a Filed to Object?

Add it to libjava/java/langObject.h
and gcc/java/class.c in make_class_data() after sync_info.
It must be after the GC bitmap marking descriptor.  Be aware that the offset
from the start of the object is used in the marking descriptor.  You're going
to have to get used to the way that works.

I think that's it, but you'll have to try it.


  reply	other threads:[~2011-06-08 18:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-08 17:20 Noah Heusser
2011-06-08 18:31 ` Andrew Haley [this message]
2011-06-10  9:39   ` Noah Heusser

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).