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Hi,
<br> you can find a pretty good description of
Sun's VM implementation in the following book. Sun is "very proud" and
so will discuss/disclose almost anything.
<p><A HREF="http://java.sun.com/docs/books/performance/">http://java.sun.com/docs/books/performance/</A>
<br>
<p>Kaffe is not very much documented. You can find some description of
some of its parts at
<p><A HREF="http://www.CS.McGill.CA/~laporte/kaffereport/report.html">http://www.CS.McGill.CA/~laporte/kaffereport/report.html</A>
<p>Regards,
<br>
<pre>--
Philippe Laporte Tel: (510) 527-4025 ext 14
Transvirtual Technologies, Inc., Fax: (510) 559-3287
Berkeley, CA, USA. Email: philippe@transvirtual.com</pre>
<p>
<br>
<br>
<br>
<p>Nathan Meyers wrote:
<blockquote TYPE=CITE>On Mon, Feb 12, 2001 at 07:08:24AM -0800, Steve Sansha
wrote:
<br>> Also: Does the Virtual Machine allow self-modifying
<br>> code? I'm sure it's possible for the bytecode to
<br>> create a new byte[] and use custom-built classloader
<br>> to actually load it, but is their an easier
<br>> alternative?
<br>> (I'm guessing it's not, since it's a type-safe
<br>> language)
<p>You may find a broken VM implementation that lets you do such a thing,
but
<br>Java's pretty strict about access to memory. Writing into space occupied
<br>by loaded bytecodes isn't in spec. And, with the possibility that the
code
<br>has been JITted, changing bytecodes on the fly would be very bad news.
<p>Custom classloaders are easy to write - there really is no "easier
<br>alternative". Loading your own manufactured bytecodes requires an almost
<br>trivial subclass of ClassLoader.
<p>> Also: I'm sending this to Kaffe because it seems to be
<br>> the best-documented, best-spirited VM... But just so I
<br>>
<br>> know, are their any documents (except the in-source
<br>> code documentation) for Sun's reference
<br>> implementation? I've looked around and can't find
<br>> any.
<p>Sun publishes detailed specs about the language, the JVM, the classfile
<br>format, and such. As for details on JVM implementation - I doubt it.
And
<br>that's a moving target anyway.
<p>Nathan
<p>>
<br>> (Thanks * 1,000,000) -Steve
<br>>
<br>>
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