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:
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Constructor SummaryConstructorsConstructorDescriptionAtomicReferenceArray(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.
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Method SummaryModifier and TypeMethodDescriptionfinal EaccumulateAndGet(int i, E x, BinaryOperator<E> accumulatorFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith the results of applying the given function to the current and given values, returning the updated value.final EcompareAndExchange(int i, E expectedValue, E newValue) Atomically sets the element at indexitonewValueif the element's current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...).final EcompareAndExchangeAcquire(int i, E expectedValue, E newValue) Atomically sets the element at indexitonewValueif the element's current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...).final EcompareAndExchangeRelease(int i, E expectedValue, E newValue) Atomically sets the element at indexitonewValueif the element's current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...).final booleancompareAndSet(int i, E expectedValue, E newValue) Atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...).final Eget(int i) Returns the current value of the element at indexi, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).final EgetAcquire(int i) Returns the current value of the element at indexi, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...).final EgetAndAccumulate(int i, E x, BinaryOperator<E> accumulatorFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith the results of applying the given function to the current and given values, returning the previous value.final EAtomically sets the element at indexitonewValueand returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...).final EgetAndUpdate(int i, UnaryOperator<E> updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith the results of applying the given function, returning the previous value.final EgetOpaque(int i) Returns the current value of the element at indexi, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...).final EgetPlain(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 voidSets the element at indexitonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).final intlength()Returns the length of the array.final voidSets the element at indexitonewValue, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...).final voidSets the element at indexitonewValue, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...).final voidSets the element at indexitonewValue, with memory semantics of setting as if the variable was declared non-volatileand non-final.final voidsetRelease(int i, E newValue) Sets the element at indexitonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).toString()Returns the String representation of the current values of array.final EupdateAndGet(int i, UnaryOperator<E> updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith the results of applying the given function, returning the updated value.final booleanweakCompareAndSet(int i, E expectedValue, E newValue) Deprecated.final booleanweakCompareAndSetAcquire(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...).final booleanweakCompareAndSetPlain(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).final booleanweakCompareAndSetRelease(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...).final booleanweakCompareAndSetVolatile(int i, E expectedValue, E newValue) Possibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...).
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Constructor Details- 
AtomicReferenceArraypublic AtomicReferenceArray(int length) Creates a new AtomicReferenceArray of the given length, with all elements initially null.- Parameters:
- length- the length of the array
 
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AtomicReferenceArrayCreates 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
 
 
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Method Details- 
lengthpublic final int length()Returns the length of the array.- Returns:
- the length of the array
 
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getReturns 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
 
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setSets the element at indexitonewValue, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...).- Parameters:
- i- the index
- newValue- the new value
 
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lazySetSets the element at indexitonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).- Parameters:
- i- the index
- newValue- the new value
- Since:
- 1.6
 
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getAndSetAtomically sets the element at indexitonewValueand returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...).- Parameters:
- i- the index
- newValue- the new value
- Returns:
- the previous value
 
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compareAndSetAtomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...).- Parameters:
- i- the index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful. False return indicates that the actual value was not equal to the expected value.
 
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weakCompareAndSetDeprecated.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 indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).- Parameters:
- i- the index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- See Also:
 
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weakCompareAndSetPlainPossibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).- Parameters:
- i- the index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
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getAndUpdateAtomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith 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 index
- updateFunction- a side-effect-free function
- Returns:
- the previous value
- Since:
- 1.8
 
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updateAndGetAtomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith 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 index
- updateFunction- a side-effect-free function
- Returns:
- the updated value
- Since:
- 1.8
 
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getAndAccumulateAtomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith 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 indexias its first argument, and the given update as the second argument.- Parameters:
- i- the index
- x- the update value
- accumulatorFunction- a side-effect-free function of two arguments
- Returns:
- the previous value
- Since:
- 1.8
 
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accumulateAndGetAtomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the element at indexiwith 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 indexias its first argument, and the given update as the second argument.- Parameters:
- i- the index
- x- the update value
- accumulatorFunction- a side-effect-free function of two arguments
- Returns:
- the updated value
- Since:
- 1.8
 
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toString
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getPlainReturns 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
 
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setPlainSets the element at indexitonewValue, with memory semantics of setting as if the variable was declared non-volatileand non-final.- Parameters:
- i- the index
- newValue- the new value
- Since:
- 9
 
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getOpaqueReturns 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
 
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setOpaqueSets the element at indexitonewValue, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...).- Parameters:
- i- the index
- newValue- the new value
- Since:
- 9
 
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getAcquireReturns 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
 
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setReleaseSets the element at indexitonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).- Parameters:
- i- the index
- newValue- the new value
- Since:
- 9
 
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compareAndExchangeAtomically sets the element at indexitonewValueif 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 index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
 
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compareAndExchangeAcquireAtomically sets the element at indexitonewValueif 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 index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
 
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compareAndExchangeReleaseAtomically sets the element at indexitonewValueif 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 index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- the witness value, which will be the same as the expected value if successful
- Since:
- 9
 
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weakCompareAndSetVolatilePossibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...).- Parameters:
- i- the index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
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weakCompareAndSetAcquirePossibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...).- Parameters:
- i- the index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
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weakCompareAndSetReleasePossibly atomically sets the element at indexitonewValueif the element's current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...).- Parameters:
- i- the index
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
 
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compareAndExchange(int, E, E)andcompareAndSet(int, E, E)).