Class CyclicTimeouts<T extends CyclicTimeouts.Expirable>

java.lang.Object

org.eclipse.jetty.io.CyclicTimeouts<T>

Type Parameters:

T - the CyclicTimeouts.Expirable entity type

All Implemented Interfaces:

Destroyable

public abstract class CyclicTimeouts<T extends CyclicTimeouts.Expirable>
extends Object
implements Destroyable

An implementation of a timeout that manages many expirable entities whose timeouts are mostly cancelled or re-scheduled.

A typical scenario is for a parent entity to manage the timeouts of many children entities.

When a new entity is created, call schedule(Expirable) with the new entity so that this instance can be aware and manage the timeout of the new entity.

Eventually, this instance wakes up and iterates over the entities provided by iterator(). During the iteration, each entity:

• may never expire (see CyclicTimeouts.Expirable.getExpireNanoTime(); the entity is ignored
• may be expired; onExpired(Expirable) is called with that entity as parameter
• may expire at a future time; the iteration records the earliest expiration time among all non-expired entities

When the iteration is complete, this instance is re-scheduled with the earliest expiration time calculated during the iteration.

See Also:

• CyclicTimeout

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CyclicTimeouts.Expirable	An entity that may expire.

Constructor Summary

Constructors

Constructor	Description
CyclicTimeouts(Scheduler scheduler)

Method Summary

Modifier and Type	Method	Description
void	destroy()
protected void	iterate()
protected abstract Iterator<T>	iterator()
protected abstract boolean	onExpired(T expirable)	Invoked during the iteration when the given entity is expired.
void	schedule(T expirable)	Schedules a timeout for a new or modified item.

Methods inherited from class Object

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

Constructor Details

CyclicTimeouts

public CyclicTimeouts(Scheduler scheduler)

Method Details

iterator

protected abstract Iterator<T> iterator()

Returns:

the entities to iterate over when this instance expires

onExpired

protected abstract boolean onExpired(T expirable)

Invoked during the iteration when the given entity is expired.

This method may be invoked multiple times, and even concurrently, for the same expirable entity and therefore the expiration of the entity, if any, should be an idempotent action.

When false is returned, the implementation should adjust the CyclicTimeouts.Expirable expiration, so that a call to CyclicTimeouts.Expirable.getExpireNanoTime() after this method has returned yields a new expiration nanoTime.

Parameters:

expirable - the entity that is expired

Returns:

whether the entity should be removed from the iterator via Iterator.remove()

iterate

protected void iterate()

schedule

public void schedule(T expirable)

Schedules a timeout for a new or modified item.

If an item returned by the iterator() has been modified or added so that it may now be the earliest expiring item, then this method should be called to schedule the timeout. This need not be called for a recurrent timeout during Expirable#onTimeoutExpired(), nor if the timeout of an existing item is increased. However, it is safe and inexpensive to always call this when modifying an item expiration time.

Parameters:

expirable - the new entity to manage the timeout for

destroy

public void destroy()

Specified by:

destroy in interface Destroyable