mmap() in C/C++ vs. Java

[beejisbrigit]

Hi there,

I was wondering if anyone had experience with File I/O in Java vs. C/C+
+ using mmap(),
and knew if the performance was better in one that the other, or more
or less negligible.
My instinct would say C/C++ is faster, but Java has made some
improvements with its
FileChannel class.

The situation is that a 1GB is to be loaded into memory and indexed as
the user needed.

thanks!
brigit.

[user923005]

On Feb 27, 8:18 am, [e-mail] wrote:

Hi there,

I was wondering if anyone had experience with File I/O in Java vs. C/C+
+ using mmap(),
and knew if the performance was better in one that the other, or more
or less negligible.
My instinct would say C/C++ is faster, but Java has made some
improvements with its
FileChannel class.

The situation is that a 1GB is to be loaded into memory and indexed as
the user needed.

Memory mapping is OS specific.
Any support for memory mapping is a compiler extension and not
directly supported by the C language per se.
Probably, you want news:comp.unix.programmer.
Of course, you'll read their FAQ first:
http://www.erlenstar.demon.co.uk/unix/

[santosh]

be**********@gmail.com wrote:

Hi there,

I was wondering if anyone had experience with File I/O in Java vs. C/C+
+ using mmap(),
and knew if the performance was better in one that the other, or more
or less negligible.
My instinct would say C/C++ is faster, but Java has made some
improvements with its
FileChannel class.

The situation is that a 1GB is to be loaded into memory and indexed as
the user needed.

thanks!
brigit.

There's no such language called 'C/C++'. The C and C++ languages
differ in subtle but important ways. Though they have a shared
history, they're better thought of as similar but distinct languages
rather than as "C/C++."

Now coming to your question, though I don't know about Java, but C and
C++ don't provide any native support for memory-mapped I/O. It's more
a facility of the underlying operating system and it's relative
performance is probably dependant on a lot of disparate factors, over
which the languages themselves are likely to have little, if any,
control.