Re: Java CORBA

1998-11-05 Thread David Wall

>What's Orbix web?

It's Iona's implementation of CORBA for Java.

>Is there a orb build-in JDK1.2?

Yes, but it's expected to be quite basic and not as powerful as products
like OrbixWeb, not to mention issues related to speed and reliability
(OrbixWeb has been available for a long time, so it's likely better tested).

>Is that mean if I get the orb from JDK1.2
>I don't need Orbix web?

Possibly.  Depends on your CORBA needs.  If need a lot of features of CORBA,
then you'll be better off with a vendor-supplied implementation.  They often
have lots of nice hooks and various CORBA Services that will not be part of
JDK 1.2, such as a persistent naming service.

David





KLGroup Chart date difference between Win98 and Linux

1998-11-05 Thread David Wall

I'm using the KLGroup's Chart product, and when applying the same program to
the same data on Windows 98 JDK 1.1.7 and Linux JDK 1.1.6v5 (Intel Redhat
5.1), the Linux chart looks very similar, but the time axis (showing dates)
is always one day earlier on Linux than the actual data shows.  It looks
correct under Win98.  And yes, both systems have their system clocks set to
the correct date.

Any ideas why they would behave differently since I doubt it's the JDK
version difference...

David
[EMAIL PROTECTED]





Re: Deprecated `Thread.stop()' in forthcoming JDK 1.2. Why?

1998-11-13 Thread David Wall

Have a method, such as stop(), that sets a boolean, and in the thread that's
running, have it loop testing if the boolean has been set by stop() or not,
and if so, then exit itself.

Stopping a thread otherwise is problematic because it is not clear where it
was when it was stopped (it's an ugly stop).  I've heard it mentioned that
it can also leave some threads in a bad a state, but that seems more like a
bug with the JVM not doing clean-up to me.   But stopping nicely is always
best...

David




Re: FSCKING MAIL LIST

1998-11-28 Thread David Wall

Rather than FSCK this kind of childish behaviour, I think he's more in need
of an 'init -6' to clean out his dirty ram...



Re: How to getAppletContext when the applet web page is inactive ?

1998-12-04 Thread David Wall

You might be happier trying a regular Java discussion list in
comp.lang.java.programmer or the like.

But, saying that, my opinion is that I don't like your applet if it runs
even if I leave the page.  That's like a rogue applet that runs even when I
leave the page that is supposed to have the applet.

DW




Re: [FYI] Java violates US patent?

1998-12-07 Thread David Wall

>What is the idea of Java? Portable code.

If that's all they claim, they will lose, since portable code has existed
long before their patent.  Now, portable code inside web browser may be
different, though some might argue that HTML itself is code that executes
inside a browser, so again, such patents may be VERY hard to enforce.

David




Re: Java.Linux.GUI

1998-12-11 Thread David Wall

Most unix-oriented GUIs, including Java, run on TOP of X-windows, just like
Java runs on top of MS Windows.

David




RMI hangs on remote calls

1999-01-21 Thread David Wall




I don't know if this is a Linux-only problem or 
Java-specific since I run the servers under Linux.
 
I have a publish-subscribe system that use RMI to 
"push" events to subscribers by invoking
an operation on the subscriber's remote object that they 
provide when they subscribe for events.
 
I have one client in particular, Win98 also running JDK 1.1.7a 
from Sun, that seems to hang itself
up sometimes when the screen saver kicks in.  Win98 will 
report a GPF and perhaps the "illegal
operation" dialog is system modal, but whenever events 
are pushed to this client while in this
state, the Linux server hangs sending this event for a long 
time (I've seen it hang for one hour!).
Fortunately, the publisher uses multiple threads, so many 
subscribers still get the events, but all
of the subscribers that are serviced by the hung thread all 
get blocked until the Win98 client
fixes itself.
 
Is there a reason why an RMI operation call blocks 
"forever" like this?  It would be nicer if there
was an exception thrown, like a timeout.  
 
Does anybody have a nice work-around or fix?  Is this 
Linux-specific or Java-specific?
 
I'm running JDK 1.1.7 on Intel from Blackdown, 
green threads
I'm running RedHat 5.1.
 
Thanks,David
[EMAIL PROTECTED]
 


Re: RMI hangs on remote calls

1999-01-21 Thread David Wall

Thanks,

Do you know how to contact the rmi-users mailing list?  I'd like to check
them out.

I guess I understand RMI's behavior since there's no such thing as a fixed
amount of time that a method ought to execute within.  It's just a pain when
the method you call hangs up.

I've been reluctant to use a thread per client (there can be hundreds of
clients) since I'm worried about running so many threads -- especially if I
moved over to native threads sometime in the future.  Is there much
experience out there with running lots of threads?  I don't even know how
well (though I could write a test program, but I have so much other work to
do!) green threads would work in the JVM if I had hundreds of client push
threads responding to each event.

David



Re: Green/Native threads

1999-02-07 Thread David Wall

>This makes me wonder.
>AFAIK, according to their definition, threads are supposed to be
"lightweight"
>processes.
>How are linuxthreads actually implemented? ie, do we get the real
lightweight
>process that we are supposed to get by the pthreads definitions?
>The descriptions seen in the discussion so far imply that this is not the
case,
>while it should be (and we should not have to worry that much about
overhead ;-}


I think it depends on the Linux distribution and the Java distribution.  The
last I read about Blackdown for Linux on Intel was that threads were rather
heavyweight, since there were comments about having to ensure you have
enough process descriptors and such...  It would be nice to get
clarifcation, since I've not attempted native threads because they seemed
like they'd be too heavy.

So, I have assumed (incorrectly, most likely!) that getting a dual processor
system would not really allow a single JVM to make use of concurrent
programming with green threads, but it would with native threads, albeit
they're heavier than most think of for threads.  Is this true?

David



Re: createImage() always returns null

1999-02-14 Thread David Wall

Chris wrote:
>is the Panel already visible?
>
>If not, then show() it before getting a Image!


Or just do an addNotify() before...this gets the peers started



Re: multi JVM's mem usage in linux?

1999-03-22 Thread David Wall

>Why I ask is that I have tried the above scenario and have found that
>having 3 jvm's running uses up almost 3x the memory of having 1 runnning
>- leading me to think there is no sharing and wondering how much memory
>I'm going to need if I want to have a large number of small
>(co-operating) java apps running similtaneously (I know an alternative
>would be to use something like echidna which will let multiple apps run
>inside 1 vm, but will this is a nice solution it still has a problem
>since apps in the same vm are vulnerable to each other, ie. if one of
>the apps dies it can take the whole vm and all the other apps in it with
>it).


Or you could run a single JVM with each "application" running in its own
thread.  They should not interfere with each other (much!), provided your
applications don't expect to be able to call System.exit() and other global
methods.

David



--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]



Re: go back to gzip!

1999-03-30 Thread David Wall

It was a bit rude as written, and that's part of the problem with email in
general.  Sometimes terse statements sound worse than the intended message
was to be delivered.

While I am really happy with the work that this free software team has been
doing, and I appreciate and make good use of their labor, the original post
did have a good point: why introduce a new zip scheme that would not be
available to most people?  gzip is open source and widely deployed.  Was
there a particularly strong reason for using bzip2 over gzip?

David


> It always amazes me when people using free software are rude to the
> folks who are doing the work. Your message was impolite, and you were
> too lazy to go find bzip2, thereby wasting everyone else's time.
>
> You can get bzip2 at
>   http://ma.us.mirrors.freshmeat.net/appindex/1998/04/15/892661723.html



--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]