ibis.constellation.util

Class FlexibleEventCollector

java.lang.Object

ibis.constellation.Activity

ibis.constellation.util.FlexibleEventCollector

All Implemented Interfaces:

java.io.Serializable

public class FlexibleEventCollector
extends Activity

A FlexibleEventCollector is an Activity that just waits for events, indefinitely, and collects them. It provides a method waitForEvents(), to be used by other activities, to collect the events collected so far.

See Also:

Serialized Form

Field Summary

Fields inherited from class ibis.constellation.Activity

FINISH, SUSPEND

Constructor Summary

Constructors

Constructor and Description
FlexibleEventCollector(AbstractContext c) Constructs a FlexibleEventCollector with the specified activity context.

Method Summary

Modifier and Type	Method and Description
void	cleanup(Constellation c) The implementation of this method is called when the activity is finished.
int	initialize(Constellation c) The implementation of this method should perform the initial processing when the activity is first activated.
int	process(Constellation c, Event e) The implementation of this method is called when an event is received for this activity.
java.lang.String	toString()
Event[]	waitForEvents() This method blocks waiting for events.

Methods inherited from class ibis.constellation.Activity

expectsEvents, getContext, identifier, mayBeStolen, setIdentifier

Methods inherited from class java.lang.Object

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

Constructor Detail

FlexibleEventCollector

public FlexibleEventCollector(AbstractContext c)

Constructs a FlexibleEventCollector with the specified activity context. Note: this is an activity that will receive events (see Activity.Activity(AbstractContext, boolean)).

Parameters:

c - the activity context

Method Detail

initialize

public int initialize(Constellation c)

Description copied from class: Activity

The implementation of this method should perform the initial processing when the activity is first activated. It may perform as much processing as needed, but should not block for a prolonged period, as this may result in deadlocks. When finished, it should return either Activity.SUSPEND or Activity.FINISH, depending on what the activity is to do next: Activity.SUSPEND when it wants to wait for events, and Activity.FINISH when it is done. Note that this method does not throw checked exceptions. It can, however, throw runtime exceptions or errors, and the Constellation running this Activity will deal with that.

Specified by:

initialize in class Activity

Parameters:

c - the Constellation on which the Activity is running

Returns:

either FINISH if this Activity is done or SUSPEND if this Activity expects events.

process

public int process(Constellation c,
                   Event e)

Description copied from class: Activity

The implementation of this method is called when an event is received for this activity. After the event is processed it must return Activity.SUSPEND or Activity.FINISH, depending on what the activity is to do next: Activity.SUSPEND when it expects other events, and Activity.FINISH when it is done. This method is invoked once at a time, even if more events arrive more or less simultaneously. Note that this method does not throw checked exceptions. It can, however, throw runtime exceptions or errors, and the Constellation running this Activity will deal with that.

Specified by:

process in class Activity

Parameters:

c - the Constellation on which the Activity is running

e - the Event to process.

Returns:

either FINISH if this Activity is done or SUSPEND if this Activity expects events.

cleanup

public void cleanup(Constellation c)

Description copied from class: Activity

The implementation of this method is called when the activity is finished. It allows the activity to perform cleanup, and, for example, send events to its parent activity. Note that this method does not throw checked exceptions. It can, however, throw runtime exceptions or errors, and the Constellation running this Activity will deal with that.

Specified by:

cleanup in class Activity

Parameters:

c - the Constellation on which the Activity is running

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

waitForEvents

public Event[] waitForEvents()

This method blocks waiting for events. As soon as one or more are available, it creates an array containing these events, clears the event list of this collector, and returns the array.

Returns:

an array containing the received events.