org.pepsoft.util

Class ParallelProgressManager

java.lang.Object

org.pepsoft.util.ParallelProgressManager

public class ParallelProgressManager
extends Object

A manager of parallel progress receivers, which reports to one parent progress receiver, combining the progress values and managing the reporting of exceptions or task completion.

1. Instantiate it with a parent progress receiver, and a task count (if known). Note: the parent progress receiver should be thread safe and not make assumptions about which threads its methods will be invoked from!
2. Invoke createProgressReceiver() as many times as needed. Note: if the manager has not been created with a task count you cannot invoke this method any more after the first task has started!
3. Start the tasks in background threads and invoke join() on the manager to wait for all tasks to complete (defined as either invoking ProgressReceiver.done() or ProgressReceiver.exceptionThrown(Throwable) on their progress receivers).

If a task invokes ProgressReceiver.exceptionThrown(Throwable) it will be reported to the parent progress receiver, and all subsequent invocations on their progress receivers by any other tasks will result in an ProgressReceiver.OperationCancelled exception being thrown. If any more exceptions are reported these are not reported to the parent progress receiver (instead they are logged using the java.util logging framework). Also, if an exception has been reported, ProgressReceiver.done() will not subsequently be invoked on the parent progress receiver.

If no exceptions are reported, ProgressReceiver.done() will be invoked on the parent progress receiver after the last task has invoked it on its sub progress receiver.

All invocations on ProgressReceiver.setMessage(String) are passed through unaltered to the parent progress receiver.

If the parent progress receiver throws an OperationCancelled exception at any time, it is stored and rethrown to every task whenever they next invoke a method (that declares it) on their sub progress receivers. It is immediately rethrown to the calling task.

Constructor Summary

Constructors

Constructor and Description
ParallelProgressManager(ProgressReceiver progressReceiver)
ParallelProgressManager(ProgressReceiver progressReceiver, int taskCount)

Method Summary

Modifier and Type	Method and Description
ProgressReceiver	createProgressReceiver()
boolean	isExceptionThrown()
void	join()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ParallelProgressManager

public ParallelProgressManager(ProgressReceiver progressReceiver)

ParallelProgressManager

public ParallelProgressManager(ProgressReceiver progressReceiver,
                               int taskCount)

Method Detail

createProgressReceiver

public ProgressReceiver createProgressReceiver()

join

public void join()
          throws InterruptedException

Throws:

InterruptedException

isExceptionThrown

public boolean isExceptionThrown()