RE: Never Ending Java Program

You could have the code that is executed by the timer event, check a data
queue (or data area I suppose) and if that?s set to a certain value then
stop the thread if required.

-----Original Message-----
From: java400-l-bounces@xxxxxxxxxxxx [mailto:java400-l-bounces@xxxxxxxxxxxx]
On Behalf Of Blalock, Bill
Sent: 22 August 2008 15:26
To: Java Programming on and around the iSeries / AS400
Subject: RE: Never Ending Java Program

Nigel:

If
while (!false);
is removed how would the "process" be managed?

The Timer will continue to run after the main() method falls out the bottom
since the JVM was not ended by System.exit();

How would you manage the "process" once it leaves main()?

Bill Blalock

-----Original Message-----
From: java400-l-bounces@xxxxxxxxxxxx [mailto:java400-l-bounces@xxxxxxxxxxxx]
On Behalf Of NGay@xxxxxxxxxxxxx
Sent: Friday, August 22, 2008 5:33 AM
To: Java Programming on and around the iSeries / AS400
Subject: Re: Never Ending Java Program

James,

Aha, and there it is:
while (!false);

That's what's eating up all your CPU. The Timer runs creates its own
thread so there's no need to keep the thread that your main () method is
running in alive. You then need to change your
timer_ = new Timer (true);
to
timer_ = new Timer (false);

With this param as "true", the Timer thread WILL end as soon as the main ()
thread ends.

Hope this helps,

Nigel Gay.




"James Perkins"
<jrperkinsjr@gmai
l.com> To
Sent by: "Java Programming on and around the
java400-l-bounces iSeries / AS400"
@midrange.com <java400-l@xxxxxxxxxxxx>
cc

21/08/2008 06:04 Subject
PM Re: Never Ending Java Program


Please respond to
Java Programming
on and around the
iSeries / AS400
<java400-l@midran
ge.com>






Thanks for the info Joe.

Here is the test class that implements the FileListener interface that goes
with this. I'm still in my learning phase with Java and it seems every time
I think I have it figured out, there is one more thing pops up.

I will start with just changing the interval. All I really want to do with
this is fire a program call when a file is added to the directory. At this
point I'm just seeing if it's possible/feasible to do it this way.

public class Test implements FileListener {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Test t = new Test();
DirectoryMonitor dirMon = new DirectoryMonitor(1000);
//FileMonitor dirMon = new FileMonitor(1000);
try {
dirMon.addDirectory(new IFSFile(new AS400("localhost",
"username", "password"), "/home"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
dirMon.addListener(t);

while (!false);
}

public void fileAdded(IFSFile file) {
System.out.println("Added: " + file.getName());
}

public void fileChanged(IFSFile file) {
System.out.println("Changed: " + file.getName());
}

public void fileRemoved(IFSFile file) {
System.out.println("Removed: " + file.getName());
}

}


Thanks,
--
James R. Perkins

On Thu, Aug 21, 2008 at 12:33 PM, Joe Sam Shirah
<joe_sam@xxxxxxxxxxxxx>wrote:

Hi James,

Your Timer invocation looks OK. The other thing that (always)

matters,

aside from the interval frequency, is what the thread is actually doing;
that is, how intensive is and how long does DirectoryMonitorNotifier()

run?

Clearly it's doing disk accesses, which are relatively slow. What

does

the constructor do, since you're creating a new one every time. Just
thread
frequency shouldn't account for 120% (interesting number) and 11 % of CPU
respectively. One of my favorite stories, although it doesn't involve
Timers or threads, has to do with a client running a third party package
that provided them with *18 hour* End of *Day* processing. Think about
that. Things got a lot better after we did a softwarectomy.

Another option, if the constructor is intense, is to use the same
DirectoryMonitorNotifier with its own yield/sleep thread(s).

I have Timers for several operations at various clients (happens that
none of them, so far, are AS/400 boxes ) and haven't seen problems.
However, typical frequencies are 5 - 10 minutes.


Joe Sam

Joe Sam Shirah - http://www.conceptgo.com
conceptGO - Consulting/Development/Outsourcing
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----- Original Message -----
From: "James Perkins" <jrperkinsjr@xxxxxxxxx>
To: "Java Programming on and around the iSeries / AS400"
<java400-l@xxxxxxxxxxxx>
Sent: Thursday, August 21, 2008 2:06 PM
Subject: Re: Never Ending Java Program


Thorbjørn,
I'm using a TimerTask, so in the code I don't yield or sleep.

Here is what the constructor looks like.
public DirectoryMonitor(long interval) {
files_ = new HashMap();
dirs_ = new HashMap();
listeners_ = new ArrayList();

timer_ = new Timer(true);
timer_.schedule(new DirectoryMonitorNotifier(), 0, interval);
}

I got most of the code from some where, can't remember exactly. It might

be

work re-working to implement Runnable and use Observer and Observable to
notify. I've never used TimerTask before so I don't know much about it.

--
Thanks,
James R. Perkins

On Thu, Aug 21, 2008 at 9:30 AM, Thorbjørn Ravn Andersen <
thunderaxiom@xxxxxxxxx> wrote:

James Perkins skrev den 21-08-2008 17:27

I have ran it interactively and it was using about 120% of the CPU.

In

batch

it was around 11%.

How often do you run Thread.yield() and Thread.sleep() ?

--
Thorbjørn Ravn Andersen "... plus... Tubular Bells!"

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