org.erights.e.elib.ref
Class NearRef

java.lang.Object
  |
  +--org.erights.e.elib.ref.Ref
        |
        +--org.erights.e.elib.ref.NearRef

All Implemented Interfaces:

Amplifiable, Callable

class NearRef

extends Ref

A NearRef represents the Ref facet of a promise which has been fulfilled with a local non-Ref object.

In E, a NearRef is forever identical to the object it wraps (the target). In the ELib implementation, NearRefs exist purely for implementation convenience to wrap a non-Ref with a Ref interface. Note that all non-Refs are considered NEAR.

Author:

Mark S. Miller

Field Summary

private Object

myTarget

Fields inherited from class org.erights.e.elib.ref.Ref

BROKEN, EVENTUAL, NEAR, TheViciousRef

Constructor Summary

(package private)

NearRef(Object target) Wrap target in Ref protocol.

Method Summary

Object	callAll(String verb, Object[] args) Synchronously forward the message and response.
(package private) void	commit() Used by a resolvers to turn off switchability, and thereby make this Ref equivalent to its current target.
boolean	isResolved() Suppressed:
Throwable	optProblem() Returns null.
Object	resolution() Returns the near object.
(package private) Ref	resolutionRef() Returns this, since target isn't a Ref
Ref	sendAll(String verb, Object[] args) Asynchronously forward the message and response.
Throwable	sendAllOnly(String verb, Object[] args) Asynchronously forward the message.
(package private) void	setTarget(Ref newTarget) Used by a resolvers to change the target.
String	state() Returns NEAR.

Methods inherited from class org.erights.e.elib.ref.Ref

broken, disconnected, getAllegedType, getOptProxyHandler, GetRefMaker, ignore, isBroken, isDeepFrozen, isDeepPassByCopy, isEventual, isFar, isNear, isPassByProxy, isPBC, isPersistent, isResolved, isSameEver, isSelfish, isSelfless, isSettled, makeBufferingPromise, makeSwitchablePromise, optBroken, optProblem, optSealedDispatch, optSealedDispatch, optShorten, promise, resolution, respondsTo, sendMsg, state, toCallable, toRef, toString, whenBroken, whenBrokenOnly, whenResolved, whenResolvedOnly

Methods inherited from class java.lang.Object

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

Field Detail

myTarget

private final Object myTarget

Constructor Detail

NearRef

NearRef(Object target)

Wrap target in Ref protocol. target must be a non-Ref.

Method Detail

optProblem

public Throwable optProblem()

Returns null.

All implementations of optProblem/0 must be thread safe, in order for Ref.state/0 to be thread safe.

Specified by:

optProblem in class Ref

Returns:

null

See Also:

Ref.optProblem(Object)

resolutionRef

Ref resolutionRef()

Returns this, since target isn't a Ref

All implementations of resolutionRef/0 must be thread safe, in order for Ref.resolution/0 to be thread safe.

Specified by:

resolutionRef in class Ref

Returns:

this.

resolution

public Object resolution()

Returns the near object.

All implementations of resolution/0 must be thread safe, in order for Ref.resolution/1 to be thread safe.

Overrides:

resolution in class Ref

Returns:

the actual target

state

public String state()

Returns NEAR.

All implementations of state/0 must be thread safe, in order for Ref.isNear/1 to be thread safe.

Overrides:

state in class Ref

Returns:

BROKEN

See Also:

Ref.state(Object)

callAll

public Object callAll(String verb,
                      Object[] args)

Synchronously forward the message and response.

Specified by:

callAll in interface Callable

Specified by:

callAll in class Ref

sendAll

public Ref sendAll(String verb,
                   Object[] args)

Asynchronously forward the message and response.

Specified by:

sendAll in class Ref

sendAllOnly

public Throwable sendAllOnly(String verb,
                             Object[] args)

Asynchronously forward the message.

Specified by:

sendAllOnly in class Ref

Returns:

Why wasn't this event queued? It isn't queued if this vat or comm connection is shut down, in which case the returned problem explains why. If null is returned, then the event was queued, though it may still not arrive.

isResolved

public boolean isResolved()

Description copied from class: Ref

Suppressed:

Specified by:

isResolved in class Ref

setTarget

void setTarget(Ref newTarget)

Description copied from class: Ref

Used by a resolvers to change the target. If newTarget is equivalent to this Ref, then this Ref becomes broken by a ViciousCycleException.

Specified by:

setTarget in class Ref

commit

void commit()

Description copied from class: Ref

Used by a resolvers to turn off switchability, and thereby make this Ref equivalent to its current target.

If the current target is already equivalent to this Ref, then this Ref becomes broken by a ViciousCycleException.

Specified by:

commit in class Ref