org.apache.cassandra.utils.concurrent

Class Refs<T extends RefCounted<T>>

java.lang.Object

java.util.AbstractCollection<T>

org.apache.cassandra.utils.concurrent.Refs<T>

All Implemented Interfaces:

java.lang.AutoCloseable, java.lang.Iterable<T>, java.util.Collection<T>

public final class Refs<T extends RefCounted<T>>
extends java.util.AbstractCollection<T>
implements java.lang.AutoCloseable

A collection of managed Ref references to RefCounted objects, and the objects they are referencing. Care MUST be taken when using this collection, as if a permanent reference to it leaks we will not be alerted to a lack of reference release. All of the java.util.Collection operations that modify the collection are unsupported.

Constructor Summary

Constructors

Constructor and Description
Refs()
Refs(java.util.Map<T,Ref<T>> references)

Method Summary

Methods

Modifier and Type	Method and Description
Refs<T>	addAll(Refs<T> add) Merge two sets of references, ensuring only one reference is retained between the two sets
void	close() See release()
Ref<T>	get(T referenced)
java.util.Iterator<T>	iterator()
static <T extends RefCounted<T>> Refs<T>	ref(java.lang.Iterable<T> reference)
void	relaseAllExcept(java.util.Collection<T> keep)
void	release() Release ALL of the references held by this Refs collection
void	release(java.util.Collection<T> release) Release a retained Ref to all of the provided objects; if any is not held, an exception will be thrown
static void	release(java.lang.Iterable<? extends Ref<?>> refs)
static java.lang.Throwable	release(java.lang.Iterable<? extends Ref<?>> refs, java.lang.Throwable accumulate)
void	release(T referenced)
boolean	releaseIfHolds(T referenced) Release the retained Ref to the provided object, if held, return false otherwise
static <T extends SelfRefCounted<T>> java.lang.Iterable<Ref<T>>	selfRefs(java.lang.Iterable<T> refs)
int	size()
static <T extends RefCounted<T>> Refs<T>	tryRef(java.lang.Iterable<T> reference) Acquire a reference to all of the provided objects, or none
boolean	tryRef(T t) Attempt to take a reference to the provided object; if it has already been released, null will be returned

Methods inherited from class java.util.AbstractCollection

add, addAll, clear, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

Refs

public Refs()

Refs

public Refs(java.util.Map<T,Ref<T>> references)

Method Detail

release

public void release()

Release ALL of the references held by this Refs collection

close

public void close()

See release()

Specified by:

close in interface java.lang.AutoCloseable

get

public Ref<T> get(T referenced)

Parameters:

referenced - the object we have a Ref to

Returns:

the Ref to said object

release

public void release(T referenced)

Parameters:

referenced - the object we have a Ref to

releaseIfHolds

public boolean releaseIfHolds(T referenced)

Release the retained Ref to the provided object, if held, return false otherwise

Parameters:

referenced - the object we retain a Ref to

Returns:

return true if we held a reference to the object, and false otherwise

relaseAllExcept

public void relaseAllExcept(java.util.Collection<T> keep)

release

public void release(java.util.Collection<T> release)

Release a retained Ref to all of the provided objects; if any is not held, an exception will be thrown

Parameters:

release -

tryRef

public boolean tryRef(T t)

Attempt to take a reference to the provided object; if it has already been released, null will be returned

Parameters:

t - object to acquire a reference to

Returns:

true iff success

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.lang.Iterable<T extends RefCounted<T>>

Specified by:

iterator in interface java.util.Collection<T extends RefCounted<T>>

Specified by:

iterator in class java.util.AbstractCollection<T extends RefCounted<T>>

size

public int size()

Specified by:

size in interface java.util.Collection<T extends RefCounted<T>>

Specified by:

size in class java.util.AbstractCollection<T extends RefCounted<T>>

addAll

public Refs<T> addAll(Refs<T> add)

Merge two sets of references, ensuring only one reference is retained between the two sets

tryRef

public static <T extends RefCounted<T>> Refs<T> tryRef(java.lang.Iterable<T> reference)

Acquire a reference to all of the provided objects, or none

ref

public static <T extends RefCounted<T>> Refs<T> ref(java.lang.Iterable<T> reference)

release

public static void release(java.lang.Iterable<? extends Ref<?>> refs)

release

public static java.lang.Throwable release(java.lang.Iterable<? extends Ref<?>> refs,
                          java.lang.Throwable accumulate)

selfRefs

public static <T extends SelfRefCounted<T>> java.lang.Iterable<Ref<T>> selfRefs(java.lang.Iterable<T> refs)