Package com.bytedesk.core.uid.utils

Class PaddedAtomicLong

java.lang.Object

java.lang.Number

java.util.concurrent.atomic.AtomicLong

com.bytedesk.core.uid.utils.PaddedAtomicLong

All Implemented Interfaces:

Serializable

public class PaddedAtomicLong
extends AtomicLong

Represents a padded AtomicLong to prevent the FalseSharing problem

The CPU cache line commonly be 64 bytes, here is a sample of cache line after padding:
64 bytes = 8 bytes (object reference) + 6 * 8 bytes (padded long) + 8 bytes (a long value)

Author:

yutianbao

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
long	p1	Padded 6 long (48 bytes)
long	p2	Padded 6 long (48 bytes)
long	p3	Padded 6 long (48 bytes)
long	p4	Padded 6 long (48 bytes)
long	p5	Padded 6 long (48 bytes)
long	p6	Padded 6 long (48 bytes)
private static final long	serialVersionUID

Constructor Summary

Constructors

Constructor	Description
PaddedAtomicLong()	Constructors from AtomicLong
PaddedAtomicLong(long initialValue)

Method Summary

Modifier and Type	Method	Description
long	sumPaddingToPreventOptimization()	To prevent GC optimizations for cleaning unused padded references

Methods inherited from class java.util.concurrent.atomic.AtomicLong

accumulateAndGet, addAndGet, compareAndExchange, compareAndExchangeAcquire, compareAndExchangeRelease, compareAndSet, decrementAndGet, doubleValue, floatValue, get, getAcquire, getAndAccumulate, getAndAdd, getAndDecrement, getAndIncrement, getAndSet, getAndUpdate, getOpaque, getPlain, incrementAndGet, intValue, lazySet, longValue, set, setOpaque, setPlain, setRelease, toString, updateAndGet, weakCompareAndSet, weakCompareAndSetAcquire, weakCompareAndSetPlain, weakCompareAndSetRelease, weakCompareAndSetVolatile

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

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

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

p1

public volatile long p1

Padded 6 long (48 bytes)

p2

public volatile long p2

Padded 6 long (48 bytes)

p3

public volatile long p3

Padded 6 long (48 bytes)

p4

public volatile long p4

Padded 6 long (48 bytes)

p5

public volatile long p5

Padded 6 long (48 bytes)

p6

public volatile long p6

Padded 6 long (48 bytes)

Constructor Details

PaddedAtomicLong

public PaddedAtomicLong()

Constructors from AtomicLong

PaddedAtomicLong

public PaddedAtomicLong(long initialValue)

Method Details

sumPaddingToPreventOptimization

public long sumPaddingToPreventOptimization()

To prevent GC optimizations for cleaning unused padded references