com.google.common.collect

Class ComputingConcurrentHashMap.ComputationExceptionReference<K,V>

java.lang.Object

com.google.common.collect.ComputingConcurrentHashMap.ComputationExceptionReference<K,V>

All Implemented Interfaces:

MapMakerInternalMap.ValueReference<K,V>

Enclosing class:

ComputingConcurrentHashMap<K,V>

private static final class ComputingConcurrentHashMap.ComputationExceptionReference<K,V>
extends java.lang.Object
implements MapMakerInternalMap.ValueReference<K,V>

Used to provide computation exceptions to other threads.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.lang.Throwable	t

Constructor Summary

Constructors

Constructor and Description
ComputationExceptionReference(java.lang.Throwable t)

Method Summary

Modifier and Type	Method and Description
void	clear(MapMakerInternalMap.ValueReference<K,V> newValue) Clears this reference object.
MapMakerInternalMap.ValueReference<K,V>	copyFor(java.lang.ref.ReferenceQueue<V> queue, V value, MapMakerInternalMap.ReferenceEntry<K,V> entry) Creates a copy of this reference for the given entry.
V	get() Gets the value.
MapMakerInternalMap.ReferenceEntry<K,V>	getEntry() Returns the entry associated with this value reference, or null if this value reference is independent of any entry.
boolean	isComputingReference() Returns true if the value type is a computing reference (regardless of whether or not computation has completed).
V	waitForValue() Waits for a value that may still be computing.

Methods inherited from class java.lang.Object

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

Field Detail

t

final java.lang.Throwable t

Constructor Detail

ComputationExceptionReference

ComputationExceptionReference(java.lang.Throwable t)

Method Detail

get

public V get()

Description copied from interface: MapMakerInternalMap.ValueReference

Gets the value. Does not block or throw exceptions.

Specified by:

get in interface MapMakerInternalMap.ValueReference<K,V>

getEntry

public MapMakerInternalMap.ReferenceEntry<K,V> getEntry()

Description copied from interface: MapMakerInternalMap.ValueReference

Returns the entry associated with this value reference, or null if this value reference is independent of any entry.

Specified by:

getEntry in interface MapMakerInternalMap.ValueReference<K,V>

copyFor

public MapMakerInternalMap.ValueReference<K,V> copyFor(java.lang.ref.ReferenceQueue<V> queue,
                                                       V value,
                                                       MapMakerInternalMap.ReferenceEntry<K,V> entry)

Description copied from interface: MapMakerInternalMap.ValueReference

Creates a copy of this reference for the given entry.

value may be null only for a loading reference.

Specified by:

copyFor in interface MapMakerInternalMap.ValueReference<K,V>

isComputingReference

public boolean isComputingReference()

Description copied from interface: MapMakerInternalMap.ValueReference

Returns true if the value type is a computing reference (regardless of whether or not computation has completed). This is necessary to distiguish between partially-collected entries and computing entries, which need to be cleaned up differently.

Specified by:

isComputingReference in interface MapMakerInternalMap.ValueReference<K,V>

waitForValue

public V waitForValue()
               throws java.util.concurrent.ExecutionException

Description copied from interface: MapMakerInternalMap.ValueReference

Waits for a value that may still be computing. Unlike get(), this method can block (in the case of FutureValueReference).

Specified by:

waitForValue in interface MapMakerInternalMap.ValueReference<K,V>

Throws:

java.util.concurrent.ExecutionException - if the computing thread throws an exception

clear

public void clear(MapMakerInternalMap.ValueReference<K,V> newValue)

Description copied from interface: MapMakerInternalMap.ValueReference

Clears this reference object.

Specified by:

clear in interface MapMakerInternalMap.ValueReference<K,V>

Parameters:

newValue - the new value reference which will replace this one; this is only used during computation to immediately notify blocked threads of the new value