sheduling problem

[manojdesai sompadi]

i have written a job shedular
it has two queues one directly submiitng the job another time shedular as time is set it sends the job to the queue

my queue class

public class Queue {
static LinkedList queue = new LinkedList();
   
// Add Build to the build queue
public synchronized void addBuild(Object o) {

queue.addLast(o);

notify();

}
    
// Retrieve job from the  queue; block if the queue is empty
public synchronized Object getBuild() throws InterruptedException {
while (queue.isEmpty()) {
wait();
}
          
return queue.removeFirst();
}
}
 
 
here is my queue implementor
 
class QueueImpl extends Thread {
// Special end-of-stream marker. If a worker retrieves

static final Object NO_MORE_WORK = new Object();
    String buildworkingdir = null ;
    String buildfile = null ;
    
    ExecBuild exbuild = new ExecBuild();

ExecQueue q;
    
    QueueImpl(ExecQueue q) {
this.q = q;
}
public void run() {
try {
while (true) {
// Retrieve build; block if the queue is empty


Object x = q.getBuild();

// Terminate if the end-of-stream marker was retrieved
if (x == NO_MORE_WORK) {
break;
}
                    

// do something here 
                                        System.out.println("test "); 
 
catch(Exception e){
System.out.println(" inturupted"+e);
}

}
} catch (InterruptedException e) {
}
}
}
 
 
 
here is the class i add jobs to the queue
 
public class SheduleAction extends Action {
 Queue addtoqueue = new Queue();
 
 QueueImpl queim = new  QueueImpl(addtoqueue);
 
 java.util.ArrayList queuelist = new java.util.ArrayList();

public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception {

ActionErrors errors = new ActionErrors();
ActionForward forward = new ActionForward(); // return value
forms.sheduleForm sheduleForm = (forms.sheduleForm) form;
 
try {
            
// add job to queue
 addtoqueue.addBuild("job");



} catch (Exception e) {
 
// Report the error using the appropriate name and ID.
errors.add("name", new ActionError("id"));
 
}
 
// If a message is required, save the specified key(s)
// into the request for use by the <struts:errors> tag.
 
if (!errors.isEmpty()) {
saveErrors(request, errors);
 
// Forward control to the appropriate 'failure' URI (change name as desired)
//forward = mapping.findForward("failure");
 
} else {
 
// Forward control to the appropriate 'success' URI (change name as desired)
// forward = mapping.findForward("success");
 
}
 
// Finish with
return mapping.findForward("success");
 
}
}
 
 
 
 
here is my sheduler
public class SheduleQueue {
 static LinkedList queuelist = new LinkedList();
 queue que = new queue();
        // timer 

  int delay = 5000;   // delay for 5 sec.
  int period = 1000;  // repeat every sec.
  Timer timer = new Timer();

 



BuildStatusAction statusform = new BuildStatusAction();
// Add Build to the build queue
public synchronized void addBuild(Object key ,Object value) {

queuelist.addLast(o);

}
    
// Retrieve build from the build queue; block if the queue is empty
public synchronized void addsheduledjob() throws InterruptedException {

timer.schedule( new TimerTask() {
public void run() {
// Task here ...                       
// here i have to create instance of Queue and                      
                // QueueImpl else the jobs are being added to queue but are    //not being executed  
                        // Queue addtoqueue = new Queue();
                // QueueImpl queim = new  QueueImpl(addtoqueue);
  
                       // add job to queueat sheduled time
 que.addBuild("job");
                       
}
}, delay);
 // delete the value from list once it is added to queue
}


  
 
}

here is the class i add job to shedular which in turn adds the job to queue at sheduled time

my question is in the shedulequeue class why i need to
create instance of queueimpl .. when i check at this point if thread is alive it showing the thread is alive ?

thanks in advance
[ April 23, 2005: Message edited by: Jim Yingst ]

[manojdesai sompadi]

sorry i missed to mention i started queue in
SheduleAction with queim.start() after adding job .
but i have to start the queue again in shedulequeue with new insatance of the queimpl ?when i started the thread once in sheduleaction ..why i need to start it again in shedulequeue class ?

[Henry Wong]

You have an indirect setup here. You are using a Timer (which is a task scheduler), but you are not running the tasks directly. Instead, all you do is place the real tasks onto a queue which is then run by the queueimpl class in another thread.

The reason you need the queueimpl, is because all you timer thread does is place the job onto the queue for the queue impl. It does nothing else.

Henry

[Henry Wong]

Originally posted by manojdesai sompadi:
sorry i missed to mention i started queue in
SheduleAction with queim.start() after adding job .
but i have to start the queue again in shedulequeue with new insatance of the queimpl ?when i started the thread once in sheduleaction ..why i need to start it again in shedulequeue class ?

Okay, I don't have enough code for this. In any case, could you use "code" tags. It is very difficult to read.

Thanks,
Henry

[Jim Yingst]

I added [code] tags to the first post. Manojdesai, please use these in the future to make code readable by preserving the indentation.

[David Harkness]

One thing I noticed is that you're using static members in places that don't seem correct:

Queue.queue

SheduleQueue.queuelist

Should those be instance members?

[manojdesai sompadi]

public class Queue {
static LinkedList queue = new LinkedList();
   
// Add Build to the build queue
public synchronized void addBuild(Object o) {

queue.addLast(o);

notify();

}
    
// Retrieve job from the  queue; block if the queue is empty
public synchronized Object getBuild() throws InterruptedException {
while (queue.isEmpty()) {
wait();
}
          
return queue.removeFirst();
}
}
 
 
here is my queue implementor
 
class QueueImpl extends Thread {
// Special end-of-stream marker. If a worker retrieves

static final Object NO_MORE_WORK = new Object();
    String buildworkingdir = null ;
    String buildfile = null ;
    
    ExecBuild exbuild = new ExecBuild();

ExecQueue q;
    
    QueueImpl(ExecQueue q) {
this.q = q;
}
public void run() {
try {
while (true) {
// Retrieve build; block if the queue is empty


Object x = q.getBuild();

// Terminate if the end-of-stream marker was retrieved
if (x == NO_MORE_WORK) {
break;
}
                    

// do something here 
                                        System.out.println("test "); 
 
catch(Exception e){
System.out.println(" inturupted"+e);
}

}
} catch (InterruptedException e) {
}
}
}
 
 
 
here is the class i add jobs to the queue
 
public class SheduleAction extends Action {
 Queue addtoqueue = new Queue();
 
 QueueImpl queim = new  QueueImpl(addtoqueue);
 
 java.util.ArrayList queuelist = new java.util.ArrayList();

public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception {

ActionErrors errors = new ActionErrors();
ActionForward forward = new ActionForward(); // return value
forms.sheduleForm sheduleForm = (forms.sheduleForm) form;
 
try {
                       [code] 
// add job to queue
 addtoqueue.addBuild("job");
  queim.start();

} catch (Exception e) {

// Report the error using the appropriate name and ID.
errors.add("name", new ActionError("id"));

}

// If a message is required, save the specified key(s)
// into the request for use by the <struts:errors> tag.

if (!errors.isEmpty()) {
saveErrors(request, errors);

// Forward control to the appropriate 'failure' URI (change name as desired)
//forward = mapping.findForward("failure");

} else {

// Forward control to the appropriate 'success' URI (change name as desired)
// forward = mapping.findForward("success");

}

// Finish with
return mapping.findForward("success");

}
}




here is my sheduler
public class SheduleQueue {
static LinkedList queuelist = new LinkedList();
queue que = new queue();
// timer

int delay = 5000; // delay for 5 sec.
int period = 1000; // repeat every sec.
Timer timer = new Timer();





BuildStatusAction statusform = new BuildStatusAction();
// Add Build to the build queue
public synchronized void addBuild(Object key ,Object value) {

queuelist.addLast(o);

}

// Retrieve build from the build queue; block if the queue is empty
public synchronized void addsheduledjob() throws InterruptedException {

timer.schedule( new TimerTask() {
public void run() {
// Task here ...
// here i have to create instance of Queue and
// QueueImpl else the jobs are being added to queue but are //not being executed
// Queue addtoqueue = new Queue();
// QueueImpl queim = new QueueImpl(addtoqueue);
//queim.start();
// add job to queueat sheduled time
que.addBuild("job");

}
}, delay);
// delete the value from list once it is added to queue
}




}[/code]
sorry i was not aware of code tags earlier i added them now .
thanks for the responces
in shdeuleaction class i started the thread of QueueImpl class .when i am adding jobs from sheduleQueue to this que ..then the current thread suppose to take the job in the que but the jobs are remaining in queue with out run by QueueImpl ..i have to start the thread again in the shedule Queue ?

[Jim Yingst]

Manojdesai - it looks like you're nesting code tags within other code tags, which doesn't work (as you can see above). You can edit your own posts after you make them. Just look for the little pencil-and-paper icon along the top edge of your post. Then you can fix the code tags to display like you want them to. I recommend using several separate pairs of code tags, since you have several different seciont of code, separated by sentences which are not code.

//some code

This way, text which is not code stands out from the code, and is more readable.

// some more code

See?
[ April 24, 2005: Message edited by: Jim Yingst ]