Class PushPullConcurrentQueue<E>
java.lang.Object
com.conversantmedia.util.concurrent.PushPullConcurrentQueue<E>
- All Implemented Interfaces:
ConcurrentQueue<E>
- Direct Known Subclasses:
PushPullBlockingQueue
Tuned version of Martin Thompson's push pull queue
Transfers from a single thread writer to a single thread reader are orders of nanoseconds (3-5)
This code is optimized and tested using a 64bit HotSpot JVM on an Intel x86-64 environment. Other
environments should be carefully tested before using in production.
Created by jcairns on 5/28/14.
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Field Summary
FieldsModifier and TypeFieldDescription(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) final E[]
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) final LongAdder
(package private) long
(package private) final long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) long
(package private) final int
(package private) final LongAdder
(package private) long
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionint
capacity()
void
clear()
clear the queue of all elementsfinal boolean
final boolean
isEmpty()
boolean
Add element t to the ringfinal E
peek()
return the first element in the queuepoll()
remove the first element from the queue and return itint
return all elements in the queue to the provided array, up to the size of the provided array.final int
size()
This implemention is known to be broken if preemption were to occur after reading the tail pointer.(package private) long
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Field Details
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size
final int size -
mask
final long mask -
tail
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p1
long p1 -
p2
long p2 -
p3
long p3 -
p4
long p4 -
p5
long p5 -
p6
long p6 -
p7
long p7 -
tailCache
long tailCache -
a1
long a1 -
a2
long a2 -
a3
long a3 -
a4
long a4 -
a5
long a5 -
a6
long a6 -
a7
long a7 -
a8
long a8 -
buffer
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r1
long r1 -
r2
long r2 -
r3
long r3 -
r4
long r4 -
r5
long r5 -
r6
long r6 -
r7
long r7 -
headCache
long headCache -
c1
long c1 -
c2
long c2 -
c3
long c3 -
c4
long c4 -
c5
long c5 -
c6
long c6 -
c7
long c7 -
c8
long c8 -
head
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Constructor Details
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PushPullConcurrentQueue
public PushPullConcurrentQueue(int capacity)
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Method Details
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offer
Description copied from interface:ConcurrentQueue
Add element t to the ring- Specified by:
offer
in interfaceConcurrentQueue<E>
- Parameters:
e
- - element to offer- Returns:
- boolean - true if the operation succeeded
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poll
Description copied from interface:ConcurrentQueue
remove the first element from the queue and return it- Specified by:
poll
in interfaceConcurrentQueue<E>
- Returns:
- T
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remove
Description copied from interface:ConcurrentQueue
return all elements in the queue to the provided array, up to the size of the provided array.- Specified by:
remove
in interfaceConcurrentQueue<E>
- Parameters:
e
- - The element array- Returns:
- int - the number of elements added to t
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clear
public void clear()Description copied from interface:ConcurrentQueue
clear the queue of all elements- Specified by:
clear
in interfaceConcurrentQueue<E>
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peek
Description copied from interface:ConcurrentQueue
return the first element in the queue- Specified by:
peek
in interfaceConcurrentQueue<E>
- Returns:
- E - The element
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size
public final int size()This implemention is known to be broken if preemption were to occur after reading the tail pointer. Code should not depend on size for a correct result.- Specified by:
size
in interfaceConcurrentQueue<E>
- Returns:
- int - possibly the size, or possibly any value less than capacity()
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capacity
public int capacity()- Specified by:
capacity
in interfaceConcurrentQueue<E>
- Returns:
- int - the capacity of the queue
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isEmpty
public final boolean isEmpty()- Specified by:
isEmpty
in interfaceConcurrentQueue<E>
- Returns:
- boolean - true if the queue is currently empty
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contains
- Specified by:
contains
in interfaceConcurrentQueue<E>
- Parameters:
o
- - the object to test- Returns:
- boolean - true if specified object is contained in the queue
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sumToAvoidOptimization
long sumToAvoidOptimization()
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