Re: Concurrent file read approaches?
Mark Thornton wrote:
Karl Uppiano wrote:
"Mark Thornton" <mark.p.thornton@ntl-spam-world.com> wrote in message
news:CDcWg.3715$L.2963@newsfe4-gui.ntli.net...
Karl Uppiano wrote:
I don't know the "best" approach, but NIO is very powerful and
scalable. It is about as close as you can get to overlapped I/O in
the OS.
Unfortunately the implementation of NIO doesn't allow concurrent read
(or write) on a single file channel. See the evaluation and comments
on bug 6371642.
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6371642
Mark Thornton
Bummer.
Indeed, I was rather disappointed when I found out (that bug submission
is one of mine).
Note that this problem is (as far as I know) specific to Windows. You
may be able to obtain better concurrency on other platforms.
Mark Thornton
Even if the bug has to be fixed by adding synchronization, would it be
for the whole duration of the read, until the data comes back? Or,
assuming asynchronous I/O capability at the operating system interface
level, could the lock be released once the read has been issued?
If the latter, then NIO read with specified file position might be a
simple solution to this problem. It seems worth trying, anyway.
Patricia
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