Re: Endianness of Java Virtual Machine
On Oct 30, 2:30 pm, karthikbalaguru <karthikbalagur...@gmail.com>
wrote:
On Oct 31, 2:12 am, dalouis <efsk...@gmail.com> wrote:
On Oct 30, 5:05 pm, karthikbalaguru <karthikbalagur...@gmail.com>
wrote:
Hi,
Is 'Java Virtual Machine' Big-Endian ?
Or
Is it independent of Endianness ? (That is Bi-Endian)
Can someone provide some link in the internet that discusses
more about this ?
Thx in advans,
Karthik Balaguru
Endian is something that is determined by the architecture of the
machine you are running on, therefore it would depend which platform
you are running the virtual machine on.
Although Im not sure what difference it would make for you if you are
writing java code, since java completely hides details such as this
from you.
Actually, I came across a link that states 'Java Virtual Machine is of
Big-Endian'.http://www.intel.com/design/intarch/papers/endian.pdf
I am eager to know the advantages of such a desing of Java Virtual
Machine.
Is there any link / document in the internet that discusses about
these ?
Since Java doesn't expose the representation of its primitive types
(which is one of two primary applications of endianness), it's
impossible to tell from examining the behaviour of code which way
around the bytes are stored in memory from within Java. This means
that the JVM is free to use whatever order is faster on the computer
it's running on: on LE machines (like the x86 architecture), that'll
be little-end-first; on BE machines (like the PowerPC), that would be
big-end-first.
However, Java's IO toolkit originally only provided ways to produce
external representations (the *other* primary application of
endianness, and the one the IBM whitepaper is probably referring to)
in big-endian form. Since big-end-first is the standard network byte
order for integer representation (see the POSIX htonl/htons
functions), this made sense at the time. The NIO framework includes
support for mixed- and little-endian IO.