Class AtomicLong
java.lang.Object
java.lang.Number
java.util.concurrent.atomic.AtomicLong
- All Implemented Interfaces:
- Serializable
A 
long value that may be updated atomically.  See the
 VarHandle specification for descriptions of the properties
 of atomic accesses. An AtomicLong is used in applications
 such as atomically incremented sequence numbers, and cannot be used
 as a replacement for a Long. However, this class
 does extend Number to allow uniform access by tools and
 utilities that deal with numerically-based classes.- Since:
- 1.5
- See Also:
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Constructor SummaryConstructorsConstructorDescriptionCreates a new AtomicLong with initial value0.AtomicLong(long initialValue) Creates a new AtomicLong with the given initial value.
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Method SummaryModifier and TypeMethodDescriptionfinal longaccumulateAndGet(long x, LongBinaryOperator accumulatorFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function to the current and given values, returning the updated value.final longaddAndGet(long delta) Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).final longcompareAndExchange(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...).final longcompareAndExchangeAcquire(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...).final longcompareAndExchangeRelease(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...).final booleancompareAndSet(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...).final longAtomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).doubleReturns the current value of thisAtomicLongas adoubleafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).floatReturns the current value of thisAtomicLongas afloatafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).final longget()Returns the current value, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).final longReturns the current value, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...).final longgetAndAccumulate(long x, LongBinaryOperator accumulatorFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function to the current and given values, returning the previous value.final longgetAndAdd(long delta) Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).final longAtomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).final longAtomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).final longgetAndSet(long newValue) Atomically sets the value tonewValueand returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...).final longgetAndUpdate(LongUnaryOperator updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function, returning the previous value.final longReturns the current value, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...).final longgetPlain()Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.final longAtomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).intintValue()Returns the current value of thisAtomicLongas anintafter a narrowing primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).final voidlazySet(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).longReturns the current value of thisAtomicLongas along, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).final voidset(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...).final voidsetOpaque(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...).final voidsetPlain(long newValue) Sets the value tonewValue, with memory semantics of setting as if the variable was declared non-volatileand non-final.final voidsetRelease(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).toString()Returns the String representation of the current value.final longupdateAndGet(LongUnaryOperator updateFunction) Atomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value with the results of applying the given function, returning the updated value.final booleanweakCompareAndSet(long expectedValue, long newValue) Deprecated.final booleanweakCompareAndSetAcquire(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...).final booleanweakCompareAndSetPlain(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).final booleanweakCompareAndSetRelease(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...).final booleanweakCompareAndSetVolatile(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...).Methods declared in class java.lang.NumberbyteValue, shortValue
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Constructor Details- 
AtomicLongpublic AtomicLong(long initialValue) Creates a new AtomicLong with the given initial value.- Parameters:
- initialValue- the initial value
 
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AtomicLongpublic AtomicLong()Creates a new AtomicLong with initial value0.
 
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Method Details- 
getpublic final long get()Returns the current value, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Returns:
- the current value
 
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setpublic final void set(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setVolatile(java.lang.Object...).- Parameters:
- newValue- the new value
 
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lazySetpublic final void lazySet(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).- Parameters:
- newValue- the new value
- Since:
- 1.6
 
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getAndSetpublic final long getAndSet(long newValue) Atomically sets the value tonewValueand returns the old value, with memory effects as specified byVarHandle.getAndSet(java.lang.Object...).- Parameters:
- newValue- the new value
- Returns:
- the previous value
 
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compareAndSetpublic final boolean compareAndSet(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...).- Parameters:
- 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(long, long)andcompareAndSet(long, long)). To avoid confusion over plain or volatile memory effects it is recommended that the methodweakCompareAndSetPlain(long, long)be used instead.Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- See Also:
 
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weakCompareAndSetPlainpublic final boolean weakCompareAndSetPlain(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetPlain(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
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getAndIncrementpublic final long getAndIncrement()Atomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to getAndAdd(1).- Returns:
- the previous value
 
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getAndDecrementpublic final long getAndDecrement()Atomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to getAndAdd(-1).- Returns:
- the previous value
 
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getAndAddpublic final long getAndAdd(long delta) Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).- Parameters:
- delta- the value to add
- Returns:
- the previous value
 
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incrementAndGetpublic final long incrementAndGet()Atomically increments the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to addAndGet(1).- Returns:
- the updated value
 
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decrementAndGetpublic final long decrementAndGet()Atomically decrements the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).Equivalent to addAndGet(-1).- Returns:
- the updated value
 
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addAndGetpublic final long addAndGet(long delta) Atomically adds the given value to the current value, with memory effects as specified byVarHandle.getAndAdd(java.lang.Object...).- Parameters:
- delta- the value to add
- Returns:
- the updated value
 
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getAndUpdateAtomically updates (with memory effects as specified byVarHandle.compareAndSet(java.lang.Object...)) the current value 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:
- 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 current value 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:
- 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 current value 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 as its first argument, and the given update as the second argument.- Parameters:
- 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 current value 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 as its first argument, and the given update as the second argument.- Parameters:
- 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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intValuepublic int intValue()Returns the current value of thisAtomicLongas anintafter a narrowing primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Specified by:
- intValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type int.
- See Java Language Specification:
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5.1.3 Narrowing Primitive Conversion
 
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longValuepublic long longValue()Returns the current value of thisAtomicLongas along, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...). Equivalent toget().
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floatValuepublic float floatValue()Returns the current value of thisAtomicLongas afloatafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Specified by:
- floatValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type float.
- See Java Language Specification:
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5.1.2 Widening Primitive Conversion
 
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doubleValuepublic double doubleValue()Returns the current value of thisAtomicLongas adoubleafter a widening primitive conversion, with memory effects as specified byVarHandle.getVolatile(java.lang.Object...).- Specified by:
- doubleValuein class- Number
- Returns:
- the numeric value represented by this object after conversion
          to type double.
- See Java Language Specification:
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5.1.2 Widening Primitive Conversion
 
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getPlainpublic final long getPlain()Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.- Returns:
- the value
- Since:
- 9
 
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setPlainpublic final void setPlain(long newValue) Sets the value tonewValue, with memory semantics of setting as if the variable was declared non-volatileand non-final.- Parameters:
- newValue- the new value
- Since:
- 9
 
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getOpaquepublic final long getOpaque()Returns the current value, with memory effects as specified byVarHandle.getOpaque(java.lang.Object...).- Returns:
- the value
- Since:
- 9
 
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setOpaquepublic final void setOpaque(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setOpaque(java.lang.Object...).- Parameters:
- newValue- the new value
- Since:
- 9
 
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getAcquirepublic final long getAcquire()Returns the current value, with memory effects as specified byVarHandle.getAcquire(java.lang.Object...).- Returns:
- the value
- Since:
- 9
 
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setReleasepublic final void setRelease(long newValue) Sets the value tonewValue, with memory effects as specified byVarHandle.setRelease(java.lang.Object...).- Parameters:
- newValue- the new value
- Since:
- 9
 
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compareAndExchangepublic final long compareAndExchange(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchange(java.lang.Object...).- Parameters:
- 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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compareAndExchangeAcquirepublic final long compareAndExchangeAcquire(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeAcquire(java.lang.Object...).- Parameters:
- 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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compareAndExchangeReleasepublic final long compareAndExchangeRelease(long expectedValue, long newValue) Atomically sets the value tonewValueif the current value, referred to as the witness value,== expectedValue, with memory effects as specified byVarHandle.compareAndExchangeRelease(java.lang.Object...).- Parameters:
- 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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weakCompareAndSetVolatilepublic final boolean weakCompareAndSetVolatile(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSet(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
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weakCompareAndSetAcquirepublic final boolean weakCompareAndSetAcquire(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetAcquire(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
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weakCompareAndSetReleasepublic final boolean weakCompareAndSetRelease(long expectedValue, long newValue) Possibly atomically sets the value tonewValueif the current value== expectedValue, with memory effects as specified byVarHandle.weakCompareAndSetRelease(java.lang.Object...).- Parameters:
- expectedValue- the expected value
- newValue- the new value
- Returns:
- trueif successful
- Since:
- 9
 
 
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compareAndExchange(long, long)andcompareAndSet(long, long)).