Class AtomicReferenceArray<E>
java.lang.Object
java.util.concurrent.atomic.AtomicReferenceArray<E>
- Type Parameters:
E
- The base class of elements held in this array
- All Implemented Interfaces:
Serializable
An array of object references in which elements may be updated
atomically. See the
VarHandle
specification for
descriptions of the properties of atomic accesses.- Since:
- 1.5
- See Also:
-
Constructor Summary
ConstructorDescriptionAtomicReferenceArray
(int length) Creates a new AtomicReferenceArray of the given length, with all elements initially null.AtomicReferenceArray
(E[] array) Creates a new AtomicReferenceArray with the same length as, and all elements copied from, the given array. -
Method Summary
Modifier and TypeMethodDescriptionfinal E
accumulateAndGet
(int i, E x, BinaryOperator<E> accumulatorFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function to the current and given values, returning the updated value.final E
compareAndExchange
(int i, E expectedValue, E newValue) Atomically sets the element at indexi
tonewValue
if the element's current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...)
.final E
compareAndExchangeAcquire
(int i, E expectedValue, E newValue) Atomically sets the element at indexi
tonewValue
if the element's current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...)
.final E
compareAndExchangeRelease
(int i, E expectedValue, E newValue) Atomically sets the element at indexi
tonewValue
if the element's current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...)
.final boolean
compareAndSet
(int i, E expectedValue, E newValue) Atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
.final E
get
(int i) Returns the current value of the element at indexi
, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...)
.final E
getAcquire
(int i) Returns the current value of the element at indexi
, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...)
.final E
getAndAccumulate
(int i, E x, BinaryOperator<E> accumulatorFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function to the current and given values, returning the previous value.final E
Atomically sets the element at indexi
tonewValue
and returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...)
.final E
getAndUpdate
(int i, UnaryOperator<E> updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function, returning the previous value.final E
getOpaque
(int i) Returns the current value of the element at indexi
, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...)
.final E
getPlain
(int i) Returns the current value of the element at indexi
, with memory semantics of reading as if the variable was declared non-volatile
.final void
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.final int
length()
Returns the length of the array.final void
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...)
.final void
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...)
.final void
Sets the element at indexi
tonewValue
, with memory semantics of setting as if the variable was declared non-volatile
and non-final
.final void
setRelease
(int i, E newValue) Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.toString()
Returns the String representation of the current values of array.final E
updateAndGet
(int i, UnaryOperator<E> updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function, returning the updated value.final boolean
weakCompareAndSet
(int i, E expectedValue, E newValue) Deprecated.final boolean
weakCompareAndSetAcquire
(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...)
.final boolean
weakCompareAndSetPlain
(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...)
.final boolean
weakCompareAndSetRelease
(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...)
.final boolean
weakCompareAndSetVolatile
(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...)
.
-
Constructor Details
-
AtomicReferenceArray
public AtomicReferenceArray(int length) Creates a new AtomicReferenceArray of the given length, with all elements initially null.- Parameters:
length
- the length of the array
-
AtomicReferenceArray
Creates a new AtomicReferenceArray with the same length as, and all elements copied from, the given array.- Parameters:
array
- the array to copy elements from- Throws:
NullPointerException
- if array is null
-
-
Method Details
-
length
public final int length()Returns the length of the array.- Returns:
- the length of the array
-
get
Returns the current value of the element at indexi
, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...)
.- Parameters:
i
- the index- Returns:
- the current value
-
set
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...)
.- Parameters:
i
- the indexnewValue
- the new value
-
lazySet
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.- Parameters:
i
- the indexnewValue
- the new value- Since:
- 1.6
-
getAndSet
Atomically sets the element at indexi
tonewValue
and returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...)
.- Parameters:
i
- the indexnewValue
- the new value- Returns:
- the previous value
-
compareAndSet
Atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful. False return indicates that the actual value was not equal to the expected value.
-
weakCompareAndSet
Deprecated.This method has plain memory effects but the method name implies volatile memory effects (see methods such ascompareAndExchange(int, E, E)
andcompareAndSet(int, E, E)
). To avoid confusion over plain or volatile memory effects it is recommended that the methodweakCompareAndSetPlain(int, E, E)
be used instead.Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- See Also:
-
weakCompareAndSetPlain
Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
getAndUpdate
Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.- Parameters:
i
- the indexupdateFunction
- a side-effect-free function- Returns:
- the previous value
- Since:
- 1.8
-
updateAndGet
Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.- Parameters:
i
- the indexupdateFunction
- a side-effect-free function- Returns:
- the updated value
- Since:
- 1.8
-
getAndAccumulate
Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value of the element at indexi
as its first argument, and the given update as the second argument.- Parameters:
i
- the indexx
- the update valueaccumulatorFunction
- a side-effect-free function of two arguments- Returns:
- the previous value
- Since:
- 1.8
-
accumulateAndGet
Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)
) the element at indexi
with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value of the element at indexi
as its first argument, and the given update as the second argument.- Parameters:
i
- the indexx
- the update valueaccumulatorFunction
- a side-effect-free function of two arguments- Returns:
- the updated value
- Since:
- 1.8
-
toString
-
getPlain
Returns the current value of the element at indexi
, with memory semantics of reading as if the variable was declared non-volatile
.- Parameters:
i
- the index- Returns:
- the value
- Since:
- 9
-
setPlain
Sets the element at indexi
tonewValue
, with memory semantics of setting as if the variable was declared non-volatile
and non-final
.- Parameters:
i
- the indexnewValue
- the new value- Since:
- 9
-
getOpaque
Returns the current value of the element at indexi
, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...)
.- Parameters:
i
- the index- Returns:
- the value
- Since:
- 9
-
setOpaque
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...)
.- Parameters:
i
- the indexnewValue
- the new value- Since:
- 9
-
getAcquire
Returns the current value of the element at indexi
, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...)
.- Parameters:
i
- the index- Returns:
- the value
- Since:
- 9
-
setRelease
Sets the element at indexi
tonewValue
, with memory effects as specified byVarHandle.setRelease(java.lang.Object...)
.- Parameters:
i
- the indexnewValue
- the new value- Since:
- 9
-
compareAndExchange
Atomically sets the element at indexi
tonewValue
if the element's current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
-
compareAndExchangeAcquire
Atomically sets the element at indexi
tonewValue
if the element's current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
-
compareAndExchangeRelease
Atomically sets the element at indexi
tonewValue
if the element's current value, referred to as the witness value,== expectedValue
, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
-
weakCompareAndSetVolatile
Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
weakCompareAndSetAcquire
Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
weakCompareAndSetRelease
Possibly atomically sets the element at indexi
tonewValue
if the element's current value== expectedValue
, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...)
.- Parameters:
i
- the indexexpectedValue
- the expected valuenewValue
- the new value- Returns:
true
if successful- Since:
- 9
-
compareAndExchange(int, E, E)
andcompareAndSet(int, E, E)
).